Bump version: v17.5.0

Closes #1615. The token 'end' (case-insensitive) is now accepted as an
alias for the document's last page, e.g. --pages 3-end. Resolution is
deferred until the page count is known from the input PDF.

README_ZH.md

@@ -1,8 +1,3 @@
-# OCRmyPDF 中文说明
-
-我将为您创建一个中文版的 README.md 文件。以下是基于原始英文版本的中文翻译：
-
-```markdown:/Users/huapai/PycharmProjects/OCRmyPDF/README.md
 <!-- SPDX-FileCopyrightText: 2014 Julien Pfefferkorn -->
 <!-- SPDX-FileCopyrightText: 2015 James R. Barlow -->
 <!-- SPDX-License-Identifier: CC-BY-SA-4.0 -->
@@ -16,98 +11,109 @@
 [docs]: https://readthedocs.org/projects/ocrmypdf/badge/?version=latest "RTD"
 [pyversions]: https://img.shields.io/pypi/pyversions/ocrmypdf "支持的 Python 版本"
 
-OCRmyPDF 为扫描的 PDF 文件添加 OCR 文本层，使其可以被搜索或复制粘贴。
+OCRmyPDF 会为扫描版 PDF 文件添加 OCR 文本层，使其可以搜索或复制粘贴。
 
 ```bash
-ocrmypdf                      # 这是一个可脚本化的命令行程序
+ocrmypdf                      # 它是一个可脚本化的命令行程序
-   -l eng+fra                 # 支持多种语言
+   -l eng+fra                 # 它支持多种语言
-   --rotate-pages             # 可以修正旋转错误的页面
+   --rotate-pages             # 它可以修正旋转方向错误的页面
-   --deskew                   # 可以校正倾斜的 PDF！
+   --deskew                   # 它可以校正歪斜的 PDF！
-   --title "My PDF"           # 可以更改输出元数据
+   --title "My PDF"           # 它可以更改输出元数据
-   --jobs 4                   # 默认使用多核心处理
+   --jobs 4                   # 它默认使用多个 CPU 核心
-   --output-type pdfa         # 默认生成 PDF/A 格式
+   --output-type pdfa         # 它默认生成 PDF/A
    input_scanned.pdf          # 接受 PDF 输入（或图像）
    output_searchable.pdf      # 生成经过验证的 PDF 输出
 ```
 
-[查看发布说明了解最新变更的详情](https://ocrmypdf.readthedocs.io/en/latest/release_notes.html)。
+[查看发布说明，了解最新变更详情](https://ocrmypdf.readthedocs.io/en/latest/release_notes.html)。
 
-## 主要特点
+## 主要功能
 
 - 从普通 PDF 生成可搜索的 [PDF/A](https://en.wikipedia.org/?title=PDF/A) 文件
-- 准确地将 OCR 文本放置在图像下方，便于复制/粘贴
+- 将 OCR 文本准确放置在图像下方，便于复制/粘贴
 - 保持原始嵌入图像的精确分辨率
-- 在可能的情况下，以"无损"操作方式插入 OCR 信息，不破坏任何其他内容
+- 在可能时，以“无损”操作插入 OCR 信息，不干扰任何其他内容
 - 优化 PDF 图像，通常生成比输入文件更小的文件
-- 如果需要，在执行 OCR 前对图像进行校正和/或清理
+- 按需在执行 OCR 前校正和/或清理图像
 - 验证输入和输出文件
-- 在所有可用的 CPU 核心上分配工作
+- 在所有可用 CPU 核心间分配工作
 - 使用 [Tesseract OCR](https://github.com/tesseract-ocr/tesseract) 引擎识别超过 [100 种语言](https://github.com/tesseract-ocr/tessdata)
-- 保护您的私人数据安全
+- 保护你的私有数据。
-- 适当扩展以处理包含数千页的文件
+- 可以妥善扩展，处理包含数千页的文件。
-- 在数百万 PDF 上经过实战测试
+- 已在数百万份 PDF 上经过实战检验。
 
-<img src="misc/screencast/demo.svg" alt="终端会话中的 OCRmyPDF 演示">
+<img src="misc/screencast/demo.svg" alt="OCRmyPDF 在终端会话中的演示">
 
 详情请参阅[文档](https://ocrmypdf.readthedocs.io/en/latest/)。
 
-## 开发动机
+## 动机
 
-我在网上搜索免费的命令行工具来对 PDF 文件进行 OCR：我找到了很多，但没有一个真正令人满意：
+我曾在网上寻找一款免费的命令行工具来对 PDF 文件执行 OCR：我找到了很多，但没有一个真正令人满意：
 
-- 要么它们生成的 PDF 文件中文本位置错误（使复制/粘贴变得不可能）
+- 要么生成的 PDF 文件中文本位于图像下方的错误位置（导致无法复制/粘贴）
-- 要么它们不处理重音和多语言字符
+- 要么无法处理重音字符和多语言字符
-- 要么它们改变了嵌入图像的分辨率
+- 要么会改变嵌入图像的分辨率
-- 要么它们生成了体积巨大的 PDF 文件
+- 要么生成的 PDF 文件大得离谱
-- 要么它们在尝试 OCR 时崩溃
+- 要么在尝试 OCR 时崩溃
-- 要么它们不生成有效的 PDF 文件
+- 要么无法生成有效的 PDF 文件
-- 最重要的是，它们都不生成 PDF/A 文件（专为长期存储设计的格式）
+- 除此之外，它们都不能生成 PDF/A 文件（专为长期存储设计的格式）
 
-...所以我决定开发自己的工具。
+……所以我决定开发自己的工具。
 
 ## 安装
 
-支持 Linux、Windows、macOS 和 FreeBSD。Docker 镜像也可用，同时支持 x64 和 ARM。
+支持 Linux、Windows、macOS 和 FreeBSD。也提供 Docker 镜像，同时支持 x64 和 ARM。
 
-| 操作系统                     | 安装命令                      |
+| 操作系统                      | 安装命令                       |
-| --------------------------- | ----------------------------- |
+| ----------------------------- | ------------------------------ |
-| Debian, Ubuntu              | ``apt install ocrmypdf``      |
+| Debian, Ubuntu                | ``apt install ocrmypdf``       |
-| Windows Subsystem for Linux | ``apt install ocrmypdf``      |
+| Windows Subsystem for Linux   | ``apt install ocrmypdf``       |
-| Fedora                      | ``dnf install ocrmypdf``      |
+| Fedora                        | ``dnf install ocrmypdf``       |
-| macOS (Homebrew)            | ``brew install ocrmypdf``     |
+| macOS (Homebrew)              | ``brew install ocrmypdf``      |
-| macOS (MacPorts)            | ``port install ocrmypdf``     |
+| macOS (MacPorts)              | ``port install ocrmypdf``      |
-| macOS (nix)                 | ``nix-env -i ocrmypdf``       |
+| macOS (nix)                   | ``nix-env -i ocrmypdf``        |
-| LinuxBrew                   | ``brew install ocrmypdf``     |
+| LinuxBrew                     | ``brew install ocrmypdf``      |
-| FreeBSD                     | ``pkg install py-ocrmypdf``   |
+| FreeBSD                       | ``pkg install py-ocrmypdf``    |
-| Ubuntu Snap                 | ``snap install ocrmypdf``     |
+| OpenBSD                       | ``pkg_add ocrmypdf``           |
+| Ubuntu Snap                   | ``snap install ocrmypdf``      |
 
-对于其他用户，[请参阅我们的文档](https://ocrmypdf.readthedocs.io/en/latest/installation.html)了解安装步骤。
+其他用户请[参阅我们的文档](https://ocrmypdf.readthedocs.io/en/latest/installation.html)了解安装步骤。
 
 ## 语言
 
-OCRmyPDF 使用 Tesseract 进行 OCR，并依赖其语言包。对于 Linux 用户，您通常可以找到提供语言包的软件包：
+OCRmyPDF 使用 Tesseract 执行 OCR，并依赖其语言包。对于 Linux 用户，通常可以找到提供语言包的软件包：
 
 ```bash
-# 显示所有 Tesseract 语言包的列表
-apt-cache search tesseract-ocr
 
 # Debian/Ubuntu 用户
-apt-get install tesseract-ocr-chi-sim  # 示例：安装中文简体语言包
+apt-cache search tesseract-ocr # 显示所有 Tesseract 语言包列表
+apt-get install tesseract-ocr-chi-sim  # 示例：安装简体中文语言包
+
 
 # Arch Linux 用户
 pacman -S tesseract-data-eng tesseract-data-deu # 示例：安装英语和德语语言包
 
+# OpenBSD 用户
+pkg_info -aQ tesseract  # 显示所有 Tesseract 语言包列表
+pkg_add tesseract-cym  # 示例：安装威尔士语语言包
+
 # brew macOS 用户
 brew install tesseract-lang
+
+# Fedora 用户
+dnf search tesseract-langpack # 显示所有 Tesseract 语言包列表
+dnf install tesseract-langpack-ita # 示例：安装意大利语语言包
+
+
 ```
 
-然后，您可以向 OCRmyPDF 传递 `-l LANG` 参数，提示它应该搜索哪些语言。可以请求多种语言。
+随后可以向 OCRmyPDF 传递 `-l LANG` 参数，提示它应搜索哪些语言。可以同时请求多种语言。
 
-OCRmyPDF 支持 Tesseract 4.1.1+。它会自动使用在 `PATH` 环境变量中首先找到的版本。在 Windows 上，如果 `PATH` 不提供 Tesseract 二进制文件，我们会根据 Windows 注册表使用已安装的最高版本号。
+OCRmyPDF 支持 Tesseract 4.1.1+。它会自动使用 `PATH` 环境变量中首先找到的版本。在 Windows 上，如果 `PATH` 中没有 Tesseract 二进制文件，我们会根据 Windows 注册表使用已安装的最高版本号。
 
 ## 文档和支持
 
-安装 OCRmyPDF 后，可以通过以下方式访问内置帮助，解释命令语法和选项：
+安装 OCRmyPDF 后，可以通过以下命令访问内置帮助，了解命令语法和选项：
 
 ```bash
 ocrmypdf --help
@@ -115,13 +121,13 @@ ocrmypdf --help
 
 我们的[文档托管在 Read the Docs 上](https://ocrmypdf.readthedocs.io/en/latest/index.html)。
 
-请在我们的 [GitHub issues](https://github.com/ocrmypdf/OCRmyPDF/issues) 页面上报告问题，并遵循问题模板以获得快速响应。
+请在我们的 [GitHub issues](https://github.com/ocrmypdf/OCRmyPDF/issues) 页面报告问题，并遵循 issue 模板以便快速获得响应。
 
 ## 功能演示
 
 ```bash
-# 添加 OCR 层并转换为 PDF/A
+# 添加 OCR 层并要求输出 PDF/A
-ocrmypdf input.pdf output.pdf
+ocrmypdf --output-type pdfa input.pdf output.pdf
 
 # 将图像转换为单页 PDF
 ocrmypdf input.jpg output.pdf
@@ -129,45 +135,53 @@ ocrmypdf input.jpg output.pdf
 # 就地为文件添加 OCR（仅在成功时修改文件）
 ocrmypdf myfile.pdf myfile.pdf
 
-# 使用非英语语言进行 OCR（查找您语言的 ISO 639-3 代码）
+# 使用非英语语言执行 OCR（请查找对应语言的 ISO 639-3 代码）
 ocrmypdf -l fra LeParisien.pdf LeParisien.pdf
 
 # OCR 多语言文档
 ocrmypdf -l eng+fra Bilingual-English-French.pdf Bilingual-English-French.pdf
 
-# 校正（矫正倾斜的页面）
+# 校正歪斜页面
 ocrmypdf --deskew input.pdf output.pdf
 ```
 
-更多功能，请参阅[文档](https://ocrmypdf.readthedocs.io/en/latest/index.html)。
+更多功能请参阅[文档](https://ocrmypdf.readthedocs.io/en/latest/index.html)。
 
 ## 要求
 
-除了所需的 Python 版本外，OCRmyPDF 还需要外部程序安装 Ghostscript 和 Tesseract OCR。OCRmyPDF 是纯 Python 编写的，几乎可以在所有平台上运行：Linux、macOS、Windows 和 FreeBSD。
+除所需的 Python 版本外，OCRmyPDF 还需要安装 Ghostscript 和 Tesseract OCR 这两个外部程序。OCRmyPDF 是纯 Python 项目，几乎可以在所有平台上运行：Linux、macOS、Windows 和 FreeBSD。
 
-## 媒体报道
+## 插件
 
-- [使用 OCRmyPDF 实现无纸化](https://medium.com/@ikirichenko/going-paperless-with-ocrmypdf-e2f36143f46a)
+OCRmyPDF 提供插件接口，允许扩展或替换其能力。以下是我们知道的一些插件：
-- [将扫描文档转换为带有编辑的压缩可搜索 PDF](https://medium.com/@treyharris/converting-a-scanned-document-into-a-compressed-searchable-pdf-with-redactions-63f61c34fe4c)
-- [c't 1-2014, 第 59 页](https://heise.de/-2279695)：在德国领先的 IT 杂志 c't 中详细介绍 OCRmyPDF v1.0
-- [heise Open Source, 09/2014: 使用 OCRmyPDF 进行文本识别](https://heise.de/-2356670)
-- [heise 使用 OCRmyPDF 创建可搜索的 PDF 文档](https://www.heise.de/ratgeber/Durchsuchbare-PDF-Dokumente-mit-OCRmyPDF-erstellen-4607592.html)
-- [优秀实用工具：OCRmyPDF](https://www.linuxlinks.com/excellent-utilities-ocrmypdf-add-ocr-text-layer-scanned-pdfs/)
-- [LinuxUser 使用 OCRmyPDF 和 Scanbd 自动化文本识别](https://www.linux-community.de/ausgaben/linuxuser/2021/06/texterkennung-mit-ocrmypdf-und-scanbd-automatisieren/)
-- [Y Combinator 讨论](https://news.ycombinator.com/item?id=32028752)
 
-## 商业咨询
+- [OCRmyPDF-AppleOCR](https://github.com/mkyt/ocrmypdf-AppleOCR)：用 Apple Vision Framework 替换标准 Tesseract OCR 引擎。需要 macOS。
+- [OCRmyPDF-EasyOCR](https://github.com/ocrmypdf/OCRmyPDF-EasyOCR)：用 EasyOCR 替换标准 Tesseract OCR 引擎；EasyOCR 是基于 PyTorch 的较新 OCR 引擎。强烈建议使用 GPU。
+- [OCRmyPDF-PaddleOCR](https://github.com/clefru/ocrmypdf-paddleocr)：用 PaddleOCR 替换标准 Tesseract OCR 引擎；PaddleOCR 是功能强大的 GPU 加速 OCR 引擎。
 
-如果没有公司和用户选择为功能开发和咨询提供支持，OCRmyPDF 就不会成为今天的软件。我们很乐意讨论所有咨询，无论是扩展现有功能集，还是将 OCRmyPDF 集成到更大的系统中。
+[paperless-ngx](https://docs.paperless-ngx.com/) 将 OCRmyPDF 集成到可搜索的文档管理系统中。
+
+## 新闻与媒体
+
+- [Going paperless with OCRmyPDF](https://medium.com/@ikirichenko/going-paperless-with-ocrmypdf-e2f36143f46a)
+- [Converting a scanned document into a compressed searchable PDF with redactions](https://medium.com/@treyharris/converting-a-scanned-document-into-a-compressed-searchable-pdf-with-redactions-63f61c34fe4c)
+- [c't 1-2014，第 59 页](https://heise.de/-2279695)：德国领先 IT 杂志 c't 对 OCRmyPDF v1.0 的详细介绍
+- [heise Open Source, 09/2014: Texterkennung mit OCRmyPDF](https://heise.de/-2356670)
+- [heise Durchsuchbare PDF-Dokumente mit OCRmyPDF erstellen](https://www.heise.de/ratgeber/Durchsuchbare-PDF-Dokumente-mit-OCRmyPDF-erstellen-4607592.html)
+- [Excellent Utilities: OCRmyPDF](https://www.linuxlinks.com/excellent-utilities-ocrmypdf-add-ocr-text-layer-scanned-pdfs/)
+- [LinuxUser Texterkennung mit OCRmyPDF und Scanbd automatisieren](https://www.linux-community.de/ausgaben/linuxuser/2021/06/texterkennung-mit-ocrmypdf-und-scanbd-automatisieren/)
+- [Y Combinator discussion](https://news.ycombinator.com/item?id=32028752)
+
+## 商务咨询
+
+如果没有公司和用户选择支持功能开发与咨询服务，OCRmyPDF 不会成为今天的软件。无论是扩展现有功能集，还是将 OCRmyPDF 集成到更大的系统中，我们都很乐意讨论各类咨询需求。
 
 ## 许可证
 
-OCRmyPDF 软件根据 Mozilla 公共许可证 2.0 (MPL-2.0) 授权。此许可证允许将 OCRmyPDF 与其他代码集成，包括商业和闭源代码，但要求您发布对 OCRmyPDF 所做的源代码级修改。
+OCRmyPDF 软件采用 Mozilla Public License 2.0 (MPL-2.0) 授权。该许可证允许将 OCRmyPDF 与其他代码集成，包括商业代码和闭源代码，但要求你发布对 OCRmyPDF 所做的源代码级修改。
 
-OCRmyPDF 的某些组件有其他许可证，如标准 SPDX 许可证标识符或 DEP5 版权和许可信息文件所示。一般来说，非核心代码根据 MIT 许可，文档和测试文件根据 Creative Commons ShareAlike 4.0 (CC-BY-SA 4.0) 许可。
+OCRmyPDF 的某些组件采用其他许可证，具体由标准 SPDX 许可证标识符或 DEP5 版权与许可信息文件标明。一般来说，非核心代码采用 MIT 许可证，文档和测试文件采用 Creative Commons ShareAlike 4.0 (CC-BY-SA 4.0) 许可证。
 
 ## 免责声明
 
-本软件按"原样"分发，不提供任何明示或暗示的保证或条件。
+本软件按“原样”分发，不提供任何明示或暗示的保证或条件。
-
-这份中文版 README.md 保留了原始文档的所有重要信息，包括功能介绍、安装说明、语言支持、使用示例等内容，同时保持了原始格式和结构。

docs/advanced.md

@@ -419,6 +419,70 @@ curves. In this case, you may want to use a different color conversion
 strategy. The `--color-conversion-strategy` option allows you to select a
 different strategy, such as `RGB`.
 
+## Advanced Ghostscript tuning
+
+:::{versionadded} 17.5.0
+:::
+
+OCRmyPDF intentionally hides most Ghostscript controls because Ghostscript
+is a legacy code path. The preferred PDF/A pipeline in v17+ uses pypdfium2
+as the rasterizer and verapdf to validate speculative PDF/A output, with
+Ghostscript reserved as a fallback for PDFs that cannot be made compliant
+without it. OCRmyPDF's separate optimizer (controlled by `--optimize`,
+`--jpeg-quality`, `--png-quality`, etc.) is the supported way to shrink
+output PDFs: it gives consistent results across input files, and isolates
+Ghostscript so it can focus on producing a PDF/A with as few image
+transformations as possible.
+
+The two options below are exposed for advanced users who want to tune
+Ghostscript's intermediate PDF/A output directly. Most users will get
+more predictable results from the optimizer.
+
+### `--ghostscript-jpeg-quality Q`
+
+Sets Ghostscript's `-dJPEGQ` switch for images that Ghostscript chooses
+to recompress to JPEG while building a PDF/A. `Q=0` requests maximum
+compression and `Q=100` requests best quality; if the flag is omitted,
+OCRmyPDF passes `95` (the historical default). This only affects images
+Ghostscript transcodes — existing JPEGs pass through unchanged on modern
+Ghostscript releases. For end-to-end JPEG quality tuning, prefer
+`--jpeg-quality`, which is implemented by the OCRmyPDF optimizer and is
+applied independently of whatever Ghostscript decides to do.
+
+Note: setting both `--ghostscript-jpeg-quality` and `--jpeg-quality` can
+result in double JPEG recompression, since the optimizer may re-encode
+images that Ghostscript already recompressed. This can degrade quality
+in subtle ways.
+
+### `--ghostscript-jpeg-maxdpi DPI`
+
+Enables Ghostscript's image downsampling and caps color, grayscale, and
+monochrome image resolution to `DPI`. The downsample threshold is set to
+`1.0`, so any image whose effective DPI exceeds the cap will be
+downsampled.
+
+Reducing JPEG quality is almost always a better trade than downsampling
+at the same compression budget: a 400 DPI JPEG at modest quality usually
+looks much better than a 200 DPI JPEG, because the JPEG codec can spend
+bits where they count. Downsampling is also dangerous for PDFs that
+combine a low-resolution color image with a high-resolution monochrome
+mask — capping the mask resolution can produce visible quality loss.
+For these reasons, prefer `--jpeg-quality` over `--ghostscript-jpeg-maxdpi`
+unless you specifically want to force a hard DPI cap.
+
+Example:
+
+```bash
+ocrmypdf --output-type pdfa \
+    --ghostscript-jpeg-quality 80 \
+    --ghostscript-jpeg-maxdpi 150 \
+    in.pdf out.pdf
+```
+
+These options only take effect when Ghostscript is invoked for PDF/A
+conversion (`--output-type pdfa`, `pdfa-1`, `pdfa-2`, or `pdfa-3`, or
+when `--output-type auto` falls back to Ghostscript).
+
 ## PDF/A output modes
 
 :::{versionchanged} 17.0.0

docs/cookbook.md

@@ -31,6 +31,16 @@ ocrmypdf --output-type pdf input.pdf output.pdf
 ocrmypdf --output-type pdfa --pdfa-image-compression jpeg input.pdf output.pdf
 ```
 
+### Reduce JPEG quality with the optimizer
+
+This is the recommended way to shrink JPEG content in the output. The
+optimizer applies regardless of `--output-type`, so it works on both
+plain PDFs and Ghostscript-produced PDF/A files.
+
+```bash
+ocrmypdf --optimize 2 --jpeg-quality 60 input.pdf output.pdf
+```
+
 ### Modify a file in place
 
 The file will only be overwritten if OCRmyPDF is successful.
@@ -333,12 +343,22 @@ Hyphens denote a range of pages and commas separate page numbers. If you
 prefer to use spaces, quote all of the page numbers:
 `--pages '2, 3, 5, 7'`.
 
+The token `end` (case-insensitive) is an alias for the last page in the
+document. For example, `--pages 3-end` OCRs from page 3 through the
+final page, and `--pages end` OCRs only the last page:
+
+```bash
+ocrmypdf --pages 3-end input.pdf output.pdf
+ocrmypdf --pages end input.pdf output.pdf
+```
+
 OCRmyPDF will warn if your list of page numbers contains duplicates or
-overlapping pages. OCRmyPDF does not currently account for document page
+overlapping pages. (Repeated page numbers are de-duplicated automatically,
-numbers, such as an introduction section of a book that uses Roman
+since the underlying set of pages is what matters.) OCRmyPDF does not
-numerals. It simply counts the number of virtual pieces of paper since
+currently account for document page numbers, such as an introduction
-the start. If your list of pages is out of numerical order, OCRmyPDF
+section of a book that uses Roman numerals. It simply counts the number
-will sort it for you.
+of virtual pieces of paper since the start. If your list of pages is out
+of numerical order, OCRmyPDF will sort it for you.
 
 Regardless of the argument to `--pages`, OCRmyPDF will optimize all
 pages/images in the file and convert it to PDF/A, unless you disable

docs/introduction.md

@@ -183,6 +183,11 @@ v17 addresses through alternative codepaths. When Ghostscript is used:
   `jpeg` or `lossless` to set all images to one type or the other.
   Ghostscript lacks an option to maintain the input image's format.
   (Modern Ghostscript can copy JPEG images without transcoding them.)
+  Advanced users can also tune Ghostscript's image recompression with
+  `--ghostscript-jpeg-quality` and `--ghostscript-jpeg-maxdpi`; see
+  [Advanced Ghostscript tuning](advanced.md#advanced-ghostscript-tuning).
+  Most users should prefer `--jpeg-quality` (applied by the OCRmyPDF
+  optimizer) over those Ghostscript-scoped controls.
 - Ghostscript's PDF/A conversion removes any XMP metadata that is not
   one of the standard XMP metadata namespaces for PDFs. In particular,
   PRISM Metadata is removed.

docs/optimizer.md

@@ -98,7 +98,16 @@ If `pngquant` is installed, OCRmyPDF will use it to perform quantize
 paletted images to reduce their size.
 
 The quality of JPEGs may be lowered, on the assumption that a lower
-quality image may be suitable for storage after OCR.
+quality image may be suitable for storage after OCR. Use `--jpeg-quality`
+to control the optimizer's JPEG quality target. The optimizer is the
+recommended way to reduce JPEG image sizes: it applies consistently
+regardless of whether Ghostscript was used to produce a PDF/A.
+
+If you specifically need to tune Ghostscript's own PDF/A image handling
+(for example, to force a hard DPI cap), see
+[Advanced Ghostscript tuning](advanced.md#advanced-ghostscript-tuning)
+for the separate `--ghostscript-jpeg-quality` and
+`--ghostscript-jpeg-maxdpi` options.
 
 It is not possible to optimize all image types. Uncommon image types may
 be skipped by the optimizer.

docs/releasenotes/version17.md

@@ -3,6 +3,28 @@
 
 # v17
 
+## v17.5.0
+
+- Added support for the ``end`` alias in ``--pages``, denoting the last page
+  of the document. For example, ``--pages 3-end`` OCRs from page 3 through
+  the final page. {issue}`1615`
+- Added ``--ghostscript-jpeg-quality`` and ``--ghostscript-jpeg-maxdpi``
+  advanced options for tuning Ghostscript's PDF/A output. The optimizer's
+  ``--jpeg-quality`` remains the recommended file-size control.
+- Fixed pypdfium2 rasterizer clipping content when the CropBox was smaller
+  than the MediaBox (e.g. JSTOR or cropped PDFs). {issue}`1685`
+- Fixed Form XObject cycle detection in the optimizer's image xref scan.
+  Self-referential or DAG-shaped Form graphs (notably from PowerPoint
+  exports) previously produced floods of recursion warnings and could hang
+  for minutes. {issue}`1321`
+- Tesseract config errors are now surfaced as ``TesseractConfigError`` with
+  actionable guidance, instead of crashing later with a confusing
+  ``FileNotFoundError`` on the missing hOCR output. {issue}`1687`
+- Refreshed the Chinese README translation. Thanks @cislunarspace.
+- Internal refactoring of the ``_exec`` and ``subprocess`` modules to
+  separate probing from execution.
+- CI dependency updates.
+
 ## v17.4.2
 
 - Fixed Python API unconditionally overriding ``PIL.Image.MAX_IMAGE_PIXELS``

misc/completion/ocrmypdf.bash

@@ -46,6 +46,8 @@ __ocrmypdf_arguments()
 --rasterizer                    (PDF page rasterizer)
 --rotate-pages-threshold        (page rotation confidence)
 --pdfa-image-compression        (set PDF/A image compression options)
+--ghostscript-jpeg-quality      (Ghostscript JPEG quality during PDF/A [0..100])
+--ghostscript-jpeg-maxdpi       (cap Ghostscript image DPI during PDF/A)
 --fast-web-view                 (if file size if above this amount in MB linearize PDF)
 --continue-on-soft-render-error (continue after recoverable render errors)
 --plugin                        (name of plugin to import)
@@ -337,6 +339,7 @@ __ocrmypdf_check_previous()
 
         --title|--author|--subject|--keywords|--unpaper-args|--pages|--plugin|\
         --jpeg-quality|--png-quality|--image-dpi|--oversample|--skip-big|--max-image-mpixels|\
+        --ghostscript-jpeg-quality|--ghostscript-jpeg-maxdpi|\
         --tesseract-timeout|--tesseract-non-ocr-timeout|--tesseract-downsample-above|\
         --rotate-pages-threshold|--fast-web-view)
             # argument required but no completions available

misc/completion/ocrmypdf.fish

@@ -102,6 +102,8 @@ function __fish_ocrmypdf_pdfa_compression
     echo -e "lossless\t"(_ "convert color and grayscale images to lossless (PNG)")
 end
 complete -c ocrmypdf -x -l pdfa-image-compression -a '(__fish_ocrmypdf_pdfa_compression)' -d "set PDF/A image compression options"
+complete -c ocrmypdf -x -l ghostscript-jpeg-quality -d "Ghostscript JPEG quality during PDF/A [0..100]"
+complete -c ocrmypdf -x -l ghostscript-jpeg-maxdpi -d "cap Ghostscript image DPI during PDF/A"
 
 complete -c ocrmypdf -x -s j -l jobs -d "how many worker processes to use"
 complete -c ocrmypdf -x -l title -d "set metadata"

pyproject.toml

@@ -6,7 +6,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "ocrmypdf"
-version = "17.4.2"
+version = "17.5.0"
 description = "OCRmyPDF adds an OCR text layer to scanned PDF files, allowing them to be searched"
 readme = "README.md"
 license = "MPL-2.0"

src/ocrmypdf/_exec/_probe.py

@@ -0,0 +1,72 @@
+# SPDX-FileCopyrightText: 2026 James R. Barlow
+# SPDX-License-Identifier: MPL-2.0
+"""Probe helper for external executables.
+
+Each ``ocrmypdf._exec.<tool>`` module describes its external program with a
+module-level :class:`ToolProbe` and delegates ``version()`` / ``available()``
+to it. This separates the "is the tool installed and suitable?" question
+(probing) from the "run the tool" question (execution). Work functions stay
+as pure module-level functions so they are trivially picklable for use in
+subprocess workers.
+"""
+
+from __future__ import annotations
+
+from collections.abc import Mapping
+from dataclasses import dataclass
+
+from packaging.version import Version
+
+from ocrmypdf.exceptions import MissingDependencyError
+from ocrmypdf.subprocess import get_version
+
+
+@dataclass(frozen=True)
+class ToolProbe:
+    """Describes how to detect an external executable and its version.
+
+    Attributes:
+        program: The program name as it appears on PATH (or a full path).
+        version_arg: The argument that elicits a version string.
+        version_regex: A regex with a capturing group that extracts the
+            version from the program's output.
+        version_cls: A :class:`packaging.version.Version` subclass, used for
+            tools with non-standard version strings (e.g. Tesseract).
+        env: Optional environment overrides applied when probing the version.
+        also_catch: Additional exception types that should be treated as
+            "not available" by :meth:`available`. :class:`OSError` is useful
+            for tools like verapdf whose launcher may fail with non-standard
+            errors when the JVM is missing.
+    """
+
+    program: str
+    version_arg: str = '--version'
+    version_regex: str = r'(\d+(\.\d+)*)'
+    version_cls: type[Version] = Version
+    env: Mapping[str, str] | None = None
+    also_catch: tuple[type[BaseException], ...] = ()
+
+    def version(self) -> Version:
+        """Return the installed version of the program.
+
+        Raises:
+            MissingDependencyError: if the program cannot be found or its
+                version string cannot be parsed.
+        """
+        raw = get_version(
+            self.program,
+            version_arg=self.version_arg,
+            regex=self.version_regex,
+            env=self.env,
+        )
+        return self.version_cls(raw)
+
+    def available(self) -> bool:
+        """Return whether a usable version of the program is installed."""
+        try:
+            self.version()
+        except MissingDependencyError:
+            return False
+        except self.also_catch:
+            return False
+        return True

src/ocrmypdf/_exec/ghostscript.py

@@ -16,6 +16,7 @@ from subprocess import PIPE, CalledProcessError
 from packaging.version import Version
 from PIL import Image, UnidentifiedImageError
 
+from ocrmypdf._exec._probe import ToolProbe
 from ocrmypdf.exceptions import (
     ColorConversionNeededError,
     InputFileError,
@@ -23,7 +24,7 @@ from ocrmypdf.exceptions import (
 )
 from ocrmypdf.helpers import Resolution
 from ocrmypdf.pluginspec import GhostscriptRasterDevice
-from ocrmypdf.subprocess import get_version, run, run_polling_stderr
+from ocrmypdf.subprocess import run, run_polling_stderr
 
 COLOR_CONVERSION_STRATEGIES = frozenset(
     [
@@ -69,11 +70,19 @@ class DuplicateFilter(logging.Filter):
             return True
 
 
-log.addFilter(DuplicateFilter(log))
+PROBE = ToolProbe(program=GS)
+version = PROBE.version
+available = PROBE.available
 
 
-def version() -> Version:
+def _ensure_log_filter_installed() -> None:
-    return Version(get_version(GS))
+    """Idempotently attach the duplicate-suppressing filter to the GS logger.
+
+    Called at the top of each work function so the filter is present in the
+    main process *and* in any subprocess worker that calls Ghostscript.
+    """
+    if not any(isinstance(f, DuplicateFilter) for f in log.filters):
+        log.addFilter(DuplicateFilter(log))
 
 
 def _gs_error_reported(stream) -> bool:
@@ -123,6 +132,7 @@ def rasterize_pdf(
         use_cropbox: If True, rasterize the CropBox instead of MediaBox.
             Default is False (use MediaBox).
     """
+    _ensure_log_filter_installed()
     raster_dpi = raster_dpi.round(6)
     if not page_dpi:
         page_dpi = raster_dpi
@@ -268,11 +278,14 @@ def generate_pdfa(
     *,
     compression: str,
     color_conversion_strategy: str,
+    jpeg_quality: int | None = None,
+    jpeg_maxdpi: int | None = None,
     pdf_version: str = '1.5',
     pdfa_part: str = '2',
     progressbar_class=None,
     stop_on_error: bool = False,
 ):
+    _ensure_log_filter_installed()
     # Ghostscript's compression is all or nothing. We can either force all images
     # to JPEG, force all to Flate/PNG, or let it decide how to encode the images.
     # In most case it's best to let it decide.
@@ -307,6 +320,35 @@ def generate_pdfa(
         # Windows has lots of fatal "permission denied" errors
         stop_on_error = False
 
+    # `-dJPEGQ=N` tells Ghostscript to use a JPEG quality of N, IF it decides
+    # to transcode an image to JPEG. When there are existing JPEG images,
+    # Ghostscript uses passthrough mode, so the quality level is not changed.
+    # OCRmyPDF's optimizer separately uses the `--jpeg-quality` command line
+    # option to potentially re-encode JPEG images, regardless of whether
+    # Ghostscript decided to transcode them to JPEG or not.
+    # `jpeg_quality=0` is meaningful to Ghostscript (maximum compression), so
+    # only fall back to the default when the value is None.
+    effective_jpeg_quality = jpeg_quality if jpeg_quality is not None else 95
+
+    # Downsampling images is a blunt-force way to reduce file size and almost
+    # always degrades quality more than lowering JPEG quality at the original
+    # resolution. We expose this for users with very specific needs (e.g.
+    # producing very small files for screen-only viewing); the optimizer is
+    # usually a better choice.
+    downsample_args: list[str] = []
+    if jpeg_maxdpi is not None:
+        downsample_args = [
+            "-dDownsampleColorImages=true",
+            "-dColorImageDownsampleThreshold=1.0",
+            "-dDownsampleGrayImages=true",
+            "-dGrayImageDownsampleThreshold=1.0",
+            "-dDownsampleMonoImages=true",
+            "-dMonoImageDownsampleThreshold=1.0",
+            f"-dColorImageResolution={jpeg_maxdpi}",
+            f"-dGrayImageResolution={jpeg_maxdpi}",
+            f"-dMonoImageResolution={jpeg_maxdpi}",
+        ]
+
     # nb no need to specify ProcessColorModel when ColorConversionStrategy
     # is set; see:
     # https://bugs.ghostscript.com/show_bug.cgi?id=699392
@@ -323,8 +365,9 @@ def generate_pdfa(
         ]
         + (['-dPDFSTOPONERROR'] if stop_on_error else [])
         + compression_args
+        + downsample_args
         + [
-            "-dJPEGQ=95",
+            f"-dJPEGQ={effective_jpeg_quality}",  # See note above on JPEG quality
             "-dSubsetFonts=false",  # Prevents GS from messing up some encodings
             f"-dPDFA={pdfa_part}",
             "-dPDFACompatibilityPolicy=1",

src/ocrmypdf/_exec/jbig2enc.py

@@ -9,21 +9,23 @@ from subprocess import PIPE, CalledProcessError
 
 from packaging.version import Version
 
+from ocrmypdf._exec._probe import ToolProbe
 from ocrmypdf.exceptions import MissingDependencyError
-from ocrmypdf.subprocess import get_version, run
+from ocrmypdf.subprocess import run
+
+_PROBE = ToolProbe(program='jbig2', version_regex=r'jbig2enc (\d+(\.\d+)*).*')
 
 
 def version() -> Version:
     try:
-        version = get_version('jbig2', regex=r'jbig2enc (\d+(\.\d+)*).*')
+        return _PROBE.version()
     except CalledProcessError as e:
         # TeX Live for Windows provides an incompatible jbig2.EXE which may
         # be on the PATH.
         raise MissingDependencyError('jbig2enc') from e
-    return Version(version)
 
 
-def available():
+def available() -> bool:
     try:
         version()
     except MissingDependencyError:

src/ocrmypdf/_exec/pngquant.py

@@ -8,22 +8,12 @@ from __future__ import annotations
 from pathlib import Path
 from subprocess import PIPE
 
-from packaging.version import Version
+from ocrmypdf._exec._probe import ToolProbe
+from ocrmypdf.subprocess import run
 
-from ocrmypdf.exceptions import MissingDependencyError
+PROBE = ToolProbe(program='pngquant', version_regex=r'(\d+(\.\d+)*).*')
-from ocrmypdf.subprocess import get_version, run
+version = PROBE.version
-
+available = PROBE.available
-
-def version() -> Version:
-    return Version(get_version('pngquant', regex=r'(\d+(\.\d+)*).*'))
-
-
-def available():
-    try:
-        version()
-    except MissingDependencyError:
-        return False
-    return True
 
 
 def quantize(input_file: Path, output_file: Path, quality_min: int, quality_max: int):

src/ocrmypdf/_exec/tesseract.py

@@ -17,13 +17,14 @@ from subprocess import PIPE, STDOUT, CalledProcessError, TimeoutExpired
 
 from packaging.version import Version
 
+from ocrmypdf._exec._probe import ToolProbe
 from ocrmypdf.exceptions import (
     MissingDependencyError,
     SubprocessOutputError,
     TesseractConfigError,
 )
 from ocrmypdf.pluginspec import OrientationConfidence
-from ocrmypdf.subprocess import get_version, run
+from ocrmypdf.subprocess import run
 
 log = logging.getLogger(__name__)
 
@@ -115,8 +116,13 @@ class TesseractVersion(Version):
     )
 
 
-def version() -> Version:
+PROBE = ToolProbe(
-    return TesseractVersion(get_version('tesseract', regex=r'tesseract\s(.+)'))
+    program='tesseract',
+    version_regex=r'tesseract\s(.+)',
+    version_cls=TesseractVersion,
+)
+version = PROBE.version
+available = PROBE.available
 
 
 def has_thresholding() -> bool:
@@ -287,9 +293,7 @@ def tesseract_log_output(stream: bytes) -> None:
 
     lines = text.splitlines()
     for line in lines:
-        if line.startswith(
+        if line.startswith(("Tesseract Open Source", "Warning in pixReadMem")):
-            ("Tesseract Open Source", "Warning in pixReadMem")
-        ):
             continue
         elif 'diacritics' in line:
             tlog.warning("lots of diacritics - possibly poor OCR")
@@ -309,6 +313,23 @@ def tesseract_log_output(stream: bytes) -> None:
             tlog.warning(line.strip())
         elif 'read_params_file' in line.lower():
             tlog.error(line.strip())
+            # Tesseract emits "read_params_file: Can't open <name>" when it
+            # cannot locate a config file (e.g. 'hocr', 'txt') in its
+            # tessdata configs/ directory, then exits 0 without producing
+            # the requested output. Promote to a hard error so the user
+            # sees the root cause instead of a downstream FileNotFoundError.
+            if "Can't open" in line:
+                missing = line.split("Can't open", 1)[1].strip()
+            else:
+                missing = line.strip()
+            raise TesseractConfigError(
+                f"Tesseract cannot open its config file '{missing}'. "
+                "This usually means Tesseract is installed but its config "
+                "files are missing from the tessdata configs/ directory. "
+                "On Debian/Ubuntu, ensure the 'tesseract-ocr' package is "
+                "fully installed. If you set TESSDATA_PREFIX, verify its "
+                "configs/ subdirectory contains the required files."
+            )
         else:
             tlog.info(line.strip())
 
@@ -389,6 +410,12 @@ def generate_hocr(
         raise SubprocessOutputError() from e
     else:
         tesseract_log_output(stdout)
+        if not output_hocr.exists():
+            raise SubprocessOutputError(
+                "Tesseract exited successfully but did not produce the "
+                f"expected hOCR output at {output_hocr}. Tesseract output:\n"
+                + (stdout.decode(errors='replace') if stdout else '(empty)')
+            )
         # The sidecar text file will get the suffix .txt; rename it to
         # whatever caller wants it named
         with suppress(FileNotFoundError):
@@ -457,6 +484,12 @@ def generate_pdf(
         stdout = p.stdout
         with suppress(FileNotFoundError):
             prefix.with_suffix('.txt').replace(output_text)
+        if not output_pdf.exists():
+            raise SubprocessOutputError(
+                "Tesseract exited successfully but did not produce the "
+                f"expected PDF output at {output_pdf}. Tesseract output:\n"
+                + (stdout.decode(errors='replace') if stdout else '(empty)')
+            )
     except TimeoutExpired:
         page_timedout(timeout)
         use_skip_page(output_pdf, output_text)

src/ocrmypdf/_exec/unpaper.py

@@ -14,11 +14,11 @@ from pathlib import Path
 from subprocess import PIPE, STDOUT
 from tempfile import TemporaryDirectory
 
-from packaging.version import Version
 from PIL import Image
 
+from ocrmypdf._exec._probe import ToolProbe
 from ocrmypdf.exceptions import SubprocessOutputError
-from ocrmypdf.subprocess import get_version, run
+from ocrmypdf.subprocess import run
 
 # unpaper documentation:
 # https://github.com/Flameeyes/unpaper/blob/main/doc/basic-concepts.md
@@ -46,8 +46,9 @@ class UnpaperImageTooLargeError(Exception):
         super().__init__(self.message)
 
 
-def version() -> Version:
+PROBE = ToolProbe(program='unpaper', version_regex=r'(?m).*?(\d+(\.\d+)(\.\d+)?)')
-    return Version(get_version('unpaper', regex=r'(?m).*?(\d+(\.\d+)(\.\d+)?)'))
+version = PROBE.version
+available = PROBE.available
 
 
 @contextmanager

src/ocrmypdf/_exec/verapdf.py

@@ -11,10 +11,9 @@ from pathlib import Path
 from subprocess import PIPE
 from typing import NamedTuple
 
-from packaging.version import Version
+from ocrmypdf._exec._probe import ToolProbe
-
 from ocrmypdf.exceptions import MissingDependencyError
-from ocrmypdf.subprocess import get_version, run
+from ocrmypdf.subprocess import run
 
 log = logging.getLogger(__name__)
 
@@ -27,18 +26,13 @@ class ValidationResult(NamedTuple):
     message: str
 
 
-def version() -> Version:
+PROBE = ToolProbe(
-    """Get verapdf version."""
+    program='verapdf',
-    return Version(get_version('verapdf', regex=r'veraPDF (\d+(\.\d+)*)'))
+    version_regex=r'veraPDF (\d+(\.\d+)*)',
-
+    also_catch=(OSError,),
-
+)
-def available() -> bool:
+version = PROBE.version
-    """Check if verapdf is available."""
+available = PROBE.available
-    try:
-        version()
-    except (MissingDependencyError, OSError):
-        return False
-    return True
 
 
 def output_type_to_flavour(output_type: str) -> str:

src/ocrmypdf/_options.py

@@ -65,8 +65,34 @@ class TaggedPdfMode(StrEnum):
     ignore = 'ignore'
 
 
-def _pages_from_ranges(ranges: str) -> set[int]:
+def _has_end_alias(ranges: str) -> bool:
-    """Convert page range string to set of page numbers."""
+    """Return True if the page range string uses the ``end`` alias."""
+    return 'end' in ranges.lower()
+
+
+def _resolve_page_token(token: str, total_pages: int | None) -> int:
+    """Convert a single page-number token to a 1-based integer.
+
+    The literal ``end`` (case-insensitive) is resolved to ``total_pages``. If
+    ``total_pages`` is None, an error is raised.
+    """
+    if token.lower() == 'end':
+        if total_pages is None:
+            raise BadArgsError(
+                "'end' was used in --pages but the total page count is not yet "
+                "known"
+            )
+        return total_pages
+    return int(token)
+
+
+def _pages_from_ranges(ranges: str, total_pages: int | None = None) -> set[int]:
+    """Convert page range string to set of 0-based page numbers.
+
+    The token ``end`` (case-insensitive) is an alias for the last page of the
+    document. It is resolved using ``total_pages``; if ``end`` appears in the
+    string and ``total_pages`` is None, a :class:`BadArgsError` is raised.
+    """
     pages: list[int] = []
     page_groups = ranges.replace(' ', '').split(',')
     for group in page_groups:
@@ -75,10 +101,15 @@ def _pages_from_ranges(ranges: str) -> set[int]:
         try:
             start, end = group.split('-')
         except ValueError:
-            pages.append(int(group) - 1)
+            try:
+                pages.append(_resolve_page_token(group, total_pages) - 1)
+            except ValueError:
+                raise BadArgsError(f"invalid page number '{group}'") from None
         else:
             try:
-                new_pages = list(range(int(start) - 1, int(end)))
+                start_n = _resolve_page_token(start, total_pages)
+                end_n = _resolve_page_token(end, total_pages)
+                new_pages = list(range(start_n - 1, end_n))
                 if not new_pages:
                     raise BadArgsError(
                         f"invalid page subrange '{start}-{end}'"
@@ -332,11 +363,19 @@ class OcrOptions(BaseModel):
     @field_validator('pages')
     @classmethod
     def validate_pages_format(cls, v):
-        """Convert page ranges string to set of page numbers."""
+        """Convert page ranges string to set of page numbers.
+
+        If the string uses the ``end`` alias, the original string is preserved
+        so that resolution can happen later, once the document's page count is
+        known.
+        """
         if v is None:
             return v
         if isinstance(v, set):
             return v  # Already processed
+        if _has_end_alias(v):
+            # Defer resolution until total page count is known
+            return v
 
         # Convert string ranges to set of page numbers
         return _pages_from_ranges(v)
@@ -582,6 +621,13 @@ class OcrOptions(BaseModel):
                 value = getattr(self, flat_name)
                 if value is not None:
                     kwargs[field_name] = _convert_value(value)
+            # Plugin-scoped fields that aren't in the central OcrOptions
+            # registry: argparse stores them in extra_attrs under the
+            # namespace_field name.
+            elif flat_name in self.extra_attrs:
+                value = self.extra_attrs[flat_name]
+                if value is not None:
+                    kwargs[field_name] = _convert_value(value)
             # Also check direct field name (for fields like jbig2_lossy)
             elif field_name in OcrOptions.model_fields:
                 value = getattr(self, field_name)

src/ocrmypdf/_pipelines/_common.py

@@ -343,12 +343,17 @@ def setup_pipeline(
 
 
 def do_get_pdfinfo(pdf_path: Path, executor: Executor, options) -> PdfInfo:
-    # Handle pages field - it might be a string that needs conversion
+    # Handle pages field - it might be a string that needs conversion.
+    # A string indicates the ``end`` alias was used and resolution was
+    # deferred; we resolve it now using the document's actual page count.
     check_pages = options.pages
     if isinstance(check_pages, str):
         from ocrmypdf._options import _pages_from_ranges
 
-        check_pages = _pages_from_ranges(check_pages)
+        with Pdf.open(pdf_path) as pdf:
+            total_pages = len(pdf.pages)
+        check_pages = _pages_from_ranges(check_pages, total_pages=total_pages)
+        options.pages = check_pages
 
     return get_pdfinfo(
         pdf_path,

src/ocrmypdf/_version.py

@@ -1,3 +1,3 @@
 # SPDX-FileCopyrightText: 2022 James R. Barlow
 # SPDX-License-Identifier: MPL-2.0
-__version__ = "17.4.2"
+__version__ = "17.5.0"

src/ocrmypdf/builtin_plugins/ghostscript.py

@@ -54,6 +54,27 @@ class GhostscriptOptions(BaseModel):
     pdfa_image_compression: Annotated[
         PdfaImageCompression, Field(description="PDF/A image compression method")
     ] = PdfaImageCompression.AUTO
+    jpeg_quality: Annotated[
+        int | None,
+        Field(
+            ge=0,
+            le=100,
+            description=(
+                "JPEG quality (0-100) for Ghostscript image recompression during "
+                "PDF/A generation; None uses Ghostscript's default."
+            ),
+        ),
+    ] = None
+    jpeg_maxdpi: Annotated[
+        int | None,
+        Field(
+            ge=1,
+            description=(
+                "Maximum DPI for Ghostscript image downsampling during PDF/A "
+                "generation."
+            ),
+        ),
+    ] = None
 
     @classmethod
     def add_arguments_to_parser(cls, parser, namespace: str = 'ghostscript'):
@@ -86,6 +107,35 @@ class GhostscriptOptions(BaseModel):
             "skipped.  Not supported for --output-type=pdf ; that setting "
             "preserves the original compression of all images.",
         )
+        gs.add_argument(
+            '--ghostscript-jpeg-quality',
+            type=int,
+            metavar='Q',
+            default=None,
+            dest=f'{namespace}_jpeg_quality',
+            help=(
+                "Advanced: Set Ghostscript's -dJPEGQ for images that Ghostscript "
+                "transcodes to JPEG during PDF/A generation. 0 is maximum "
+                "compression; 100 is best quality. If omitted, Ghostscript's "
+                "default is used. This only affects images Ghostscript chooses "
+                "to recompress; for general JPEG quality tuning prefer "
+                "--jpeg-quality, which is applied by the OCRmyPDF optimizer."
+            ),
+        )
+        gs.add_argument(
+            '--ghostscript-jpeg-maxdpi',
+            type=int,
+            metavar='DPI',
+            default=None,
+            dest=f'{namespace}_jpeg_maxdpi',
+            help=(
+                "Advanced: Force Ghostscript to downsample color, grayscale, "
+                "and monochrome images in PDF/A output to the given maximum DPI. "
+                "Reducing JPEG quality usually gives better results than "
+                "downsampling at the same file size, and can degrade quality "
+                "of high-resolution monochrome masks."
+            ),
+        )
 
 
 @hookimpl
@@ -352,6 +402,8 @@ def generate_pdfa(
         output_file=output_file,
         compression=context.options.ghostscript.pdfa_image_compression,
         color_conversion_strategy=context.options.ghostscript.color_conversion_strategy,
+        jpeg_quality=context.options.ghostscript.jpeg_quality,
+        jpeg_maxdpi=context.options.ghostscript.jpeg_maxdpi,
         pdf_version=pdf_version,
         pdfa_part=pdfa_part,
         progressbar_class=progressbar_class,

src/ocrmypdf/builtin_plugins/pypdfium.py

@@ -48,27 +48,18 @@ def _open_pdf_document(input_file: Path):
     return pdfium.PdfDocument(input_file)
 
 
-def _calculate_mediabox_crop(page) -> tuple[float, float, float, float]:
+def _expand_cropbox_to_mediabox(page) -> None:
-    """Calculate crop values to expand rendering from CropBox to MediaBox.
+    """Set the page's CropBox to its MediaBox so PDFium renders the full page.
 
-    By default pypdfium2 renders to the CropBox. To render the full MediaBox,
+    PDFium renders to the CropBox by default. Negative ``crop`` values to
-    we need negative crop values to expand the rendering area.
+    ``render()`` are not supported and only pad the output canvas without
-
+    expanding the rendered area — content outside the CropBox is clipped.
-    Returns:
+    The supported approach is to widen the CropBox in memory before rendering.
-        Tuple of (left, bottom, right, top) crop values. Negative values
+    The document is never saved back to disk, so this mutation is local.
-        expand the rendering area beyond the CropBox to the MediaBox.
+    See https://github.com/ocrmypdf/OCRmyPDF/issues/1685.
     """
     mediabox = page.get_mediabox()  # (left, bottom, right, top)
-    cropbox = page.get_cropbox()  # (left, bottom, right, top), defaults to mediabox
+    page.set_cropbox(*mediabox)
-
-    # Calculate how much to expand from cropbox to mediabox
-    # Negative values = expand, positive = shrink
-    return (
-        mediabox[0] - cropbox[0],  # Expand left
-        mediabox[1] - cropbox[1],  # Expand bottom
-        cropbox[2] - mediabox[2],  # Expand right
-        cropbox[3] - mediabox[3],  # Expand top
-    )
 
 
 def _render_page_to_bitmap(
@@ -107,14 +98,13 @@ def _render_page_to_bitmap(
     # Render in grayscale for mono and gray devices (better input for 1-bit conversion)
     grayscale = raster_device.lower() in ('pngmono', 'pnggray', 'jpeggray')
 
-    # Calculate crop to render the appropriate box
     # Default (use_cropbox=False) renders MediaBox for consistency with Ghostscript
-    crop = (0, 0, 0, 0) if use_cropbox else _calculate_mediabox_crop(page)
+    if not use_cropbox:
+        _expand_cropbox_to_mediabox(page)
 
     bitmap = page.render(
         scale=scale,
         rotation=0,  # We already set rotation on the page
-        crop=crop,
         may_draw_forms=True,
         draw_annots=True,
         grayscale=grayscale,

src/ocrmypdf/cli.py

@@ -387,7 +387,8 @@ Online documentation is located at:
         type=str,
         help=(
             "Limit OCR to the specified pages (ranges or comma separated), "
-            "skipping others"
+            "skipping others. The token 'end' is an alias for the last page, "
+            "so e.g. '3-end' OCRs from page 3 to the last page."
         ),
     )
     advanced.add_argument(

src/ocrmypdf/optimize.py

@@ -260,10 +260,19 @@ def _find_image_xrefs_container(
     exclude_xrefs: MutableSet[Xref],
     pageno_for_xref: dict[Xref, int],
     depth: int = 0,
+    visited_forms: MutableSet[Xref] | None = None,
 ):
     """Find all image XRefs or Form XObject and add to the include/exclude sets."""
+    # Form XObjects are not added to include/exclude_xrefs, so the dedup
+    # check below doesn't catch Form-XObject cycles or DAGs. Track them in
+    # a shared set so each Form is only descended into once per document
+    # (issue #1321).
+    if visited_forms is None:
+        visited_forms = set()
     if depth > 10:
-        log.warning("Recursion depth exceeded in _find_image_xrefs_page")
+        # With visited_forms memoization, this is a soft DAG-height guard
+        # rather than a cycle defense, so a debug log is sufficient.
+        log.debug("Recursion depth exceeded in _find_image_xrefs_page")
         return
     try:
         xobjs = container.Resources.XObject
@@ -276,7 +285,9 @@ def _find_image_xrefs_container(
         if xref in include_xrefs or xref in exclude_xrefs:
             continue  # Already processed
         if Name.Subtype in image and image.Subtype == Name.Form:
-            # Recurse into Form XObjects
+            if xref in visited_forms:
+                continue
+            visited_forms.add(xref)
             log.debug(f"Recursing into Form XObject {_imname} in page {pageno}")
             _find_image_xrefs_container(
                 pdf,
@@ -286,6 +297,7 @@ def _find_image_xrefs_container(
                 exclude_xrefs,
                 pageno_for_xref,
                 depth + 1,
+                visited_forms,
             )
             continue
         if Name.SMask in image:

src/ocrmypdf/subprocess/__init__.py

@@ -1,345 +1,31 @@
 # SPDX-FileCopyrightText: 2022 James R. Barlow
 # SPDX-License-Identifier: MPL-2.0
-"""Wrappers to manage subprocess calls."""
+"""Wrappers to manage subprocess calls.
+
+This package is split into three private submodules by concern:
+
+- :mod:`ocrmypdf.subprocess._run` - low-level execution wrappers (``run``,
+  ``run_polling_stderr``) that add OCRmyPDF-aware logging and Windows PATH
+  resolution. Useful as drop-in replacements for :func:`subprocess.run`.
+- :mod:`ocrmypdf.subprocess._version` - version probing (``get_version``).
+- :mod:`ocrmypdf.subprocess._check` - startup validation
+  (``check_external_program``) with platform-aware error messages.
+
+The names below are the stable public API. Importing from the private
+submodules directly is not supported for external code.
+"""
 
 from __future__ import annotations
 
-import logging
+from ocrmypdf.subprocess._check import check_external_program
-import os
+from ocrmypdf.subprocess._run import Args, Environ, run, run_polling_stderr
-import re
+from ocrmypdf.subprocess._version import get_version
-import sys
-from collections.abc import Callable, Mapping, Sequence
-from contextlib import suppress
-from pathlib import Path
-from subprocess import PIPE, STDOUT, CalledProcessError, CompletedProcess, Popen
-from subprocess import run as subprocess_run
 
-from packaging.version import Version
+__all__ = [
-
+    'Args',
-from ocrmypdf.exceptions import MissingDependencyError
+    'Environ',
-
+    'check_external_program',
-# pylint: disable=logging-format-interpolation
+    'get_version',
-
+    'run',
-log = logging.getLogger(__name__)
+    'run_polling_stderr',
-
+]
-Args = Sequence[Path | str]
-Environ = Mapping[str, str] | os._Environ  # pylint: disable=protected-access
-
-
-def run(
-    args: Args,
-    *,
-    env: Environ | None = None,
-    logs_errors_to_stdout: bool = False,
-    check: bool = False,
-    **kwargs,
-) -> CompletedProcess:
-    """Wrapper around :py:func:`subprocess.run`.
-
-    The main purpose of this wrapper is to log subprocess output in an orderly
-    fashion that identifies the responsible subprocess. An additional
-    task is that this function goes to greater lengths to find possible Windows
-    locations of our dependencies when they are not on the system PATH.
-
-    Arguments should be identical to ``subprocess.run``, except for following:
-
-    Args:
-        args: Positional arguments to pass to ``subprocess.run``.
-        env: A set of environment variables. If None, the OS environment is used.
-        logs_errors_to_stdout: If True, indicates that the process writes its error
-            messages to stdout rather than stderr, so stdout should be logged
-            if there is an error. If False, stderr is logged. Could be used with
-            stderr=STDOUT, stdout=PIPE for example.
-        check: If True, raise an exception if the process exits with a non-zero
-            status code. If False, the return value will indicate success or failure.
-        kwargs: Additional arguments to pass to ``subprocess.run``.
-    """
-    args, env, process_log, _text = _fix_process_args(args, env, kwargs)
-
-    stderr = None
-    stderr_name = 'stderr' if not logs_errors_to_stdout else 'stdout'
-    try:
-        proc = subprocess_run(args, env=env, check=check, **kwargs)
-    except CalledProcessError as e:
-        stderr = getattr(e, stderr_name, None)
-        raise
-    else:
-        stderr = getattr(proc, stderr_name, None)
-    finally:
-        if process_log.isEnabledFor(logging.DEBUG) and stderr:
-            with suppress(AttributeError, UnicodeDecodeError):
-                stderr = stderr.decode('utf-8', 'replace')
-            if logs_errors_to_stdout:
-                process_log.debug("stdout/stderr = %s", stderr)
-            else:
-                process_log.debug("stderr = %s", stderr)
-    return proc
-
-
-def run_polling_stderr(
-    args: Args,
-    *,
-    callback: Callable[[str], None],
-    check: bool = False,
-    env: Environ | None = None,
-    **kwargs,
-) -> CompletedProcess:
-    """Run a process like ``ocrmypdf.subprocess.run``, and poll stderr.
-
-    Every line of produced by stderr will be forwarded to the callback function.
-    The intended use is monitoring progress of subprocesses that output their
-    own progress indicators. In addition, each line will be logged if debug
-    logging is enabled.
-
-    Requires stderr to be opened in text mode for ease of handling errors. In
-    addition the expected encoding= and errors= arguments should be set. Note
-    that if stdout is already set up, it need not be binary.
-    """
-    args, env, process_log, text = _fix_process_args(args, env, kwargs)
-    assert text, "Must use text=True"
-
-    with Popen(args, env=env, **kwargs) as proc:
-        lines = []
-        while proc.poll() is None:
-            if proc.stderr is None:
-                continue
-            for msg in iter(proc.stderr.readline, ''):
-                if process_log.isEnabledFor(logging.DEBUG):
-                    process_log.debug(msg.strip())
-                callback(msg)
-                lines.append(msg)
-        stderr = ''.join(lines)
-
-        if check and proc.returncode != 0:
-            raise CalledProcessError(proc.returncode, args, output=None, stderr=stderr)
-        return CompletedProcess(args, proc.returncode, None, stderr=stderr)
-
-
-def _fix_process_args(
-    args: Args, env: Environ | None, kwargs
-) -> tuple[Args, Environ, logging.Logger, bool]:
-    if not env:
-        env = os.environ
-
-    # Search in spoof path if necessary
-    program = str(args[0])
-
-    if sys.platform == 'win32':
-        # pylint: disable=import-outside-toplevel
-        from ocrmypdf.subprocess._windows import fix_windows_args
-
-        args = fix_windows_args(program, args, env)
-
-    log.debug("Running: %s", args)
-    process_log = log.getChild(os.path.basename(program))
-    text = bool(kwargs.get('text', False))
-
-    return args, env, process_log, text
-
-
-def get_version(
-    program: str,
-    *,
-    version_arg: str = '--version',
-    regex=r'(\d+(\.\d+)*)',
-    env: Environ | None = None,
-) -> str:
-    """Get the version of the specified program.
-
-    Arguments:
-        program: The program to version check.
-        version_arg: The argument needed to ask for its version, e.g. ``--version``.
-        regex: A regular expression to parse the program's output and obtain the
-            version.
-        env: Custom ``os.environ`` in which to run program.
-    """
-    args_prog = [program, version_arg]
-    try:
-        proc = run(
-            args_prog,
-            close_fds=True,
-            text=True,
-            stdout=PIPE,
-            stderr=STDOUT,
-            check=True,
-            env=env,
-        )
-        output: str = proc.stdout
-    except FileNotFoundError as e:
-        raise MissingDependencyError(
-            f"Could not find program '{program}' on the PATH"
-        ) from e
-    except CalledProcessError as e:
-        if e.returncode != 0:
-            log.exception(e)
-            raise MissingDependencyError(
-                f"Ran program '{program}' but it exited with an error:\n{e.output}"
-            ) from e
-        raise MissingDependencyError(
-            f"Could not find program '{program}' on the PATH"
-        ) from e
-
-    match = re.match(regex, output.strip())
-    if not match:
-        raise MissingDependencyError(
-            f"The program '{program}' did not report its version. "
-            f"Message was:\n{output}"
-        )
-    version = match.group(1)
-
-    return version
-
-
-MISSING_PROGRAM = '''
-The program '{program}' could not be executed or was not found on your
-system PATH.
-'''
-
-MISSING_OPTIONAL_PROGRAM = '''
-The program '{program}' could not be executed or was not found on your
-system PATH.  This program is required when you use the
-{required_for} arguments.  You could try omitting these arguments, or install
-the package.
-'''
-
-MISSING_RECOMMEND_PROGRAM = '''
-The program '{program}' could not be executed or was not found on your
-system PATH.  This program is recommended when using the {required_for} arguments,
-but not required, so we will proceed.  For best results, install the program.
-'''
-
-OLD_VERSION = '''
-OCRmyPDF requires '{program}' {need_version} or higher.  Your system appears
-to have {found_version}.  Please update this program.
-'''
-
-OLD_VERSION_REQUIRED_FOR = '''
-OCRmyPDF requires '{program}' {need_version} or higher when run with the
-{required_for} arguments.  {program} {found_version} is installed.
-
-If you omit these arguments, OCRmyPDF may be able to
-proceed.  For best results, update the program.
-'''
-
-OSX_INSTALL_ADVICE = '''
-If you have homebrew installed, try these command to install the missing
-package:
-    brew install {package}
-'''
-
-LINUX_INSTALL_ADVICE = '''
-On systems with the aptitude package manager (Debian, Ubuntu), try these
-commands:
-    sudo apt update
-    sudo apt install {package}
-
-On RPM-based systems (Red Hat, Fedora), try this command:
-    sudo dnf install {package}
-'''
-
-WINDOWS_INSTALL_ADVICE = '''
-If not already installed, install the Chocolatey package manager. Then use
-a command prompt to install the missing package:
-    choco install {package}
-'''
-
-
-def _get_platform() -> str:
-    if sys.platform.startswith('freebsd'):
-        return 'freebsd'
-    elif sys.platform.startswith('linux'):
-        return 'linux'
-    elif sys.platform.startswith('win'):
-        return 'windows'
-    return sys.platform
-
-
-def _error_trailer(program: str, package: str | Mapping[str, str], **kwargs) -> None:
-    del kwargs
-    if isinstance(package, Mapping):
-        package = package.get(_get_platform(), program)
-
-    if _get_platform() == 'darwin':
-        log.info(OSX_INSTALL_ADVICE.format(**locals()))
-    elif _get_platform() == 'linux':
-        log.info(LINUX_INSTALL_ADVICE.format(**locals()))
-    elif _get_platform() == 'windows':
-        log.info(WINDOWS_INSTALL_ADVICE.format(**locals()))
-
-
-def _error_missing_program(
-    program: str, package: str, required_for: str | None, recommended: bool
-) -> None:
-    # pylint: disable=unused-argument
-    if recommended:
-        log.warning(MISSING_RECOMMEND_PROGRAM.format(**locals()))
-    elif required_for:
-        log.error(MISSING_OPTIONAL_PROGRAM.format(**locals()))
-    else:
-        log.error(MISSING_PROGRAM.format(**locals()))
-    _error_trailer(**locals())
-
-
-def _error_old_version(
-    program: str,
-    package: str,
-    need_version: str,
-    found_version: str,
-    required_for: str | None,
-) -> None:
-    # pylint: disable=unused-argument
-    if required_for:
-        log.error(OLD_VERSION_REQUIRED_FOR.format(**locals()))
-    else:
-        log.error(OLD_VERSION.format(**locals()))
-    _error_trailer(**locals())
-
-
-def check_external_program(
-    *,
-    program: str,
-    package: str,
-    version_checker: Callable[[], Version],
-    need_version: str | Version,
-    required_for: str | None = None,
-    recommended: bool = False,
-    version_parser: type[Version] = Version,
-) -> None:
-    """Check for required version of external program and raise exception if not.
-
-    Args:
-        program: The name of the program to test.
-        package: The name of a software package that typically supplies this program.
-            Usually the same as program.
-        version_checker: A callable without arguments that retrieves the installed
-            version of program.
-        need_version: The minimum required version.
-        required_for: The name of an argument of feature that requires this program.
-        recommended: If this external program is recommended, instead of raising
-            an exception, log a warning and allow execution to continue.
-        version_parser: A class that should be used to parse and compare version
-            numbers. Used when version numbers do not follow standard conventions.
-    """
-    if not isinstance(need_version, Version):
-        need_version = version_parser(need_version)
-    try:
-        found_version = version_checker()
-    except (CalledProcessError, FileNotFoundError) as e:
-        _error_missing_program(program, package, required_for, recommended)
-        if not recommended:
-            raise MissingDependencyError(program) from e
-        return
-    except MissingDependencyError:
-        _error_missing_program(program, package, required_for, recommended)
-        if not recommended:
-            raise
-        return
-
-    if found_version and found_version < need_version:
-        _error_old_version(
-            program, package, str(need_version), str(found_version), required_for
-        )
-        if not recommended:
-            raise MissingDependencyError(program)
-
-    log.debug('Found %s %s', program, found_version)

src/ocrmypdf/subprocess/_check.py

@@ -0,0 +1,171 @@
+# SPDX-FileCopyrightText: 2022 James R. Barlow
+# SPDX-License-Identifier: MPL-2.0
+"""Validate that required external programs are installed and new enough."""
+
+from __future__ import annotations
+
+import logging
+import sys
+from collections.abc import Callable, Mapping
+from subprocess import CalledProcessError
+
+from packaging.version import Version
+
+from ocrmypdf.exceptions import MissingDependencyError
+
+log = logging.getLogger('ocrmypdf.subprocess')
+
+
+MISSING_PROGRAM = '''
+The program '{program}' could not be executed or was not found on your
+system PATH.
+'''
+
+MISSING_OPTIONAL_PROGRAM = '''
+The program '{program}' could not be executed or was not found on your
+system PATH.  This program is required when you use the
+{required_for} arguments.  You could try omitting these arguments, or install
+the package.
+'''
+
+MISSING_RECOMMEND_PROGRAM = '''
+The program '{program}' could not be executed or was not found on your
+system PATH.  This program is recommended when using the {required_for} arguments,
+but not required, so we will proceed.  For best results, install the program.
+'''
+
+OLD_VERSION = '''
+OCRmyPDF requires '{program}' {need_version} or higher.  Your system appears
+to have {found_version}.  Please update this program.
+'''
+
+OLD_VERSION_REQUIRED_FOR = '''
+OCRmyPDF requires '{program}' {need_version} or higher when run with the
+{required_for} arguments.  {program} {found_version} is installed.
+
+If you omit these arguments, OCRmyPDF may be able to
+proceed.  For best results, update the program.
+'''
+
+OSX_INSTALL_ADVICE = '''
+If you have homebrew installed, try these command to install the missing
+package:
+    brew install {package}
+'''
+
+LINUX_INSTALL_ADVICE = '''
+On systems with the aptitude package manager (Debian, Ubuntu), try these
+commands:
+    sudo apt update
+    sudo apt install {package}
+
+On RPM-based systems (Red Hat, Fedora), try this command:
+    sudo dnf install {package}
+'''
+
+WINDOWS_INSTALL_ADVICE = '''
+If not already installed, install the Chocolatey package manager. Then use
+a command prompt to install the missing package:
+    choco install {package}
+'''
+
+
+def _get_platform() -> str:
+    if sys.platform.startswith('freebsd'):
+        return 'freebsd'
+    elif sys.platform.startswith('linux'):
+        return 'linux'
+    elif sys.platform.startswith('win'):
+        return 'windows'
+    return sys.platform
+
+
+def _error_trailer(program: str, package: str | Mapping[str, str], **kwargs) -> None:
+    del kwargs
+    if isinstance(package, Mapping):
+        package = package.get(_get_platform(), program)
+
+    if _get_platform() == 'darwin':
+        log.info(OSX_INSTALL_ADVICE.format(**locals()))
+    elif _get_platform() == 'linux':
+        log.info(LINUX_INSTALL_ADVICE.format(**locals()))
+    elif _get_platform() == 'windows':
+        log.info(WINDOWS_INSTALL_ADVICE.format(**locals()))
+
+
+def _error_missing_program(
+    program: str, package: str, required_for: str | None, recommended: bool
+) -> None:
+    # pylint: disable=unused-argument
+    if recommended:
+        log.warning(MISSING_RECOMMEND_PROGRAM.format(**locals()))
+    elif required_for:
+        log.error(MISSING_OPTIONAL_PROGRAM.format(**locals()))
+    else:
+        log.error(MISSING_PROGRAM.format(**locals()))
+    _error_trailer(**locals())
+
+
+def _error_old_version(
+    program: str,
+    package: str,
+    need_version: str,
+    found_version: str,
+    required_for: str | None,
+) -> None:
+    # pylint: disable=unused-argument
+    if required_for:
+        log.error(OLD_VERSION_REQUIRED_FOR.format(**locals()))
+    else:
+        log.error(OLD_VERSION.format(**locals()))
+    _error_trailer(**locals())
+
+
+def check_external_program(
+    *,
+    program: str,
+    package: str,
+    version_checker: Callable[[], Version],
+    need_version: str | Version,
+    required_for: str | None = None,
+    recommended: bool = False,
+    version_parser: type[Version] = Version,
+) -> None:
+    """Check for required version of external program and raise exception if not.
+
+    Args:
+        program: The name of the program to test.
+        package: The name of a software package that typically supplies this program.
+            Usually the same as program.
+        version_checker: A callable without arguments that retrieves the installed
+            version of program.
+        need_version: The minimum required version.
+        required_for: The name of an argument of feature that requires this program.
+        recommended: If this external program is recommended, instead of raising
+            an exception, log a warning and allow execution to continue.
+        version_parser: A class that should be used to parse and compare version
+            numbers. Used when version numbers do not follow standard conventions.
+    """
+    if not isinstance(need_version, Version):
+        need_version = version_parser(need_version)
+    try:
+        found_version = version_checker()
+    except (CalledProcessError, FileNotFoundError) as e:
+        _error_missing_program(program, package, required_for, recommended)
+        if not recommended:
+            raise MissingDependencyError(program) from e
+        return
+    except MissingDependencyError:
+        _error_missing_program(program, package, required_for, recommended)
+        if not recommended:
+            raise
+        return
+
+    if found_version and found_version < need_version:
+        _error_old_version(
+            program, package, str(need_version), str(found_version), required_for
+        )
+        if not recommended:
+            raise MissingDependencyError(program)
+
+    log.debug('Found %s %s', program, found_version)

src/ocrmypdf/subprocess/_run.py

@@ -0,0 +1,137 @@
+# SPDX-FileCopyrightText: 2022 James R. Barlow
+# SPDX-License-Identifier: MPL-2.0
+"""Low-level wrappers around :py:mod:`subprocess`.
+
+These functions exist to give OCRmyPDF child processes uniform logging
+behavior and to route through any platform-specific PATH fix-ups before
+invocation. They are intended as drop-in replacements for
+:py:func:`subprocess.run` in contexts where that routing is desirable
+(for example, plugin-provided tools).
+"""
+
+from __future__ import annotations
+
+import logging
+import os
+import sys
+from collections.abc import Callable, Mapping, Sequence
+from contextlib import suppress
+from pathlib import Path
+from subprocess import CalledProcessError, CompletedProcess, Popen
+from subprocess import run as subprocess_run
+
+log = logging.getLogger('ocrmypdf.subprocess')
+
+Args = Sequence[Path | str]
+Environ = Mapping[str, str] | os._Environ  # pylint: disable=protected-access
+
+
+def run(
+    args: Args,
+    *,
+    env: Environ | None = None,
+    logs_errors_to_stdout: bool = False,
+    check: bool = False,
+    **kwargs,
+) -> CompletedProcess:
+    """Wrapper around :py:func:`subprocess.run`.
+
+    The main purpose of this wrapper is to log subprocess output in an orderly
+    fashion that identifies the responsible subprocess. An additional
+    task is that this function goes to greater lengths to find possible Windows
+    locations of our dependencies when they are not on the system PATH.
+
+    Arguments should be identical to ``subprocess.run``, except for following:
+
+    Args:
+        args: Positional arguments to pass to ``subprocess.run``.
+        env: A set of environment variables. If None, the OS environment is used.
+        logs_errors_to_stdout: If True, indicates that the process writes its error
+            messages to stdout rather than stderr, so stdout should be logged
+            if there is an error. If False, stderr is logged. Could be used with
+            stderr=STDOUT, stdout=PIPE for example.
+        check: If True, raise an exception if the process exits with a non-zero
+            status code. If False, the return value will indicate success or failure.
+        kwargs: Additional arguments to pass to ``subprocess.run``.
+    """
+    args, env, process_log, _text = _fix_process_args(args, env, kwargs)
+
+    stderr = None
+    stderr_name = 'stderr' if not logs_errors_to_stdout else 'stdout'
+    try:
+        proc = subprocess_run(args, env=env, check=check, **kwargs)
+    except CalledProcessError as e:
+        stderr = getattr(e, stderr_name, None)
+        raise
+    else:
+        stderr = getattr(proc, stderr_name, None)
+    finally:
+        if process_log.isEnabledFor(logging.DEBUG) and stderr:
+            with suppress(AttributeError, UnicodeDecodeError):
+                stderr = stderr.decode('utf-8', 'replace')
+            if logs_errors_to_stdout:
+                process_log.debug("stdout/stderr = %s", stderr)
+            else:
+                process_log.debug("stderr = %s", stderr)
+    return proc
+
+
+def run_polling_stderr(
+    args: Args,
+    *,
+    callback: Callable[[str], None],
+    check: bool = False,
+    env: Environ | None = None,
+    **kwargs,
+) -> CompletedProcess:
+    """Run a process like ``ocrmypdf.subprocess.run``, and poll stderr.
+
+    Every line of produced by stderr will be forwarded to the callback function.
+    The intended use is monitoring progress of subprocesses that output their
+    own progress indicators. In addition, each line will be logged if debug
+    logging is enabled.
+
+    Requires stderr to be opened in text mode for ease of handling errors. In
+    addition the expected encoding= and errors= arguments should be set. Note
+    that if stdout is already set up, it need not be binary.
+    """
+    args, env, process_log, text = _fix_process_args(args, env, kwargs)
+    assert text, "Must use text=True"
+
+    with Popen(args, env=env, **kwargs) as proc:
+        lines = []
+        while proc.poll() is None:
+            if proc.stderr is None:
+                continue
+            for msg in iter(proc.stderr.readline, ''):
+                if process_log.isEnabledFor(logging.DEBUG):
+                    process_log.debug(msg.strip())
+                callback(msg)
+                lines.append(msg)
+        stderr = ''.join(lines)
+
+        if check and proc.returncode != 0:
+            raise CalledProcessError(proc.returncode, args, output=None, stderr=stderr)
+        return CompletedProcess(args, proc.returncode, None, stderr=stderr)
+
+
+def _fix_process_args(
+    args: Args, env: Environ | None, kwargs
+) -> tuple[Args, Environ, logging.Logger, bool]:
+    if not env:
+        env = os.environ
+
+    # Search in spoof path if necessary
+    program = str(args[0])
+
+    if sys.platform == 'win32':
+        # pylint: disable=import-outside-toplevel
+        from ocrmypdf.subprocess._windows import fix_windows_args
+
+        args = fix_windows_args(program, args, env)
+
+    log.debug("Running: %s", args)
+    process_log = log.getChild(os.path.basename(program))
+    text = bool(kwargs.get('text', False))
+
+    return args, env, process_log, text

src/ocrmypdf/subprocess/_version.py

@@ -0,0 +1,73 @@
+# SPDX-FileCopyrightText: 2022 James R. Barlow
+# SPDX-License-Identifier: MPL-2.0
+"""Extract version strings from external programs."""
+
+from __future__ import annotations
+
+import logging
+import re
+from subprocess import PIPE, STDOUT, CalledProcessError
+
+from ocrmypdf.exceptions import MissingDependencyError
+from ocrmypdf.subprocess._run import Environ
+
+log = logging.getLogger('ocrmypdf.subprocess')
+
+
+def get_version(
+    program: str,
+    *,
+    version_arg: str = '--version',
+    regex=r'(\d+(\.\d+)*)',
+    env: Environ | None = None,
+) -> str:
+    """Get the version of the specified program.
+
+    Arguments:
+        program: The program to version check.
+        version_arg: The argument needed to ask for its version, e.g. ``--version``.
+        regex: A regular expression to parse the program's output and obtain the
+            version.
+        env: Custom ``os.environ`` in which to run program.
+    """
+    # Late import of the public ``run`` so that tests patching
+    # ``ocrmypdf.subprocess.run`` affect this function. Binding ``run`` at
+    # module load time would capture the real implementation and bypass the
+    # patch.
+    from ocrmypdf import subprocess as _sp
+
+    args_prog = [program, version_arg]
+    try:
+        proc = _sp.run(
+            args_prog,
+            close_fds=True,
+            text=True,
+            stdout=PIPE,
+            stderr=STDOUT,
+            check=True,
+            env=env,
+        )
+        output: str = proc.stdout
+    except FileNotFoundError as e:
+        raise MissingDependencyError(
+            f"Could not find program '{program}' on the PATH"
+        ) from e
+    except CalledProcessError as e:
+        if e.returncode != 0:
+            log.exception(e)
+            raise MissingDependencyError(
+                f"Ran program '{program}' but it exited with an error:\n{e.output}"
+            ) from e
+        raise MissingDependencyError(
+            f"Could not find program '{program}' on the PATH"
+        ) from e
+
+    match = re.match(regex, output.strip())
+    if not match:
+        raise MissingDependencyError(
+            f"The program '{program}' did not report its version. "
+            f"Message was:\n{output}"
+        )
+    version = match.group(1)
+
+    return version

tests/test_ghostscript.py

@@ -137,6 +137,129 @@ def test_rasterize_low_dpi_one_axis(francais, outdir):
         assert im.info['dpi'] == forced_dpi
 
 
+def test_generate_pdfa_default_jpeg_quality(outdir):
+    """When jpeg_quality is None, Ghostscript receives -dJPEGQ=95 (default)."""
+    with (
+        patch('ocrmypdf._exec.ghostscript.version', return_value=Version('10.05.1')),
+        patch('ocrmypdf._exec.ghostscript.run_polling_stderr') as run_mock,
+    ):
+        run_mock.return_value = subprocess.CompletedProcess(
+            ['gs'], returncode=0, stdout='', stderr=''
+        )
+        ghostscript.generate_pdfa(
+            pdf_pages=[outdir / 'input.pdf'],
+            output_file=outdir / 'out.pdf',
+            compression='auto',
+            color_conversion_strategy='LeaveColorUnchanged',
+        )
+
+    args = run_mock.call_args.args[0]
+    assert '-dJPEGQ=95' in args
+    # No downsample switches when jpeg_maxdpi is not set
+    assert not any(a.startswith('-dDownsampleColorImages') for a in args)
+    assert not any(a.startswith('-dColorImageResolution') for a in args)
+
+
+def test_generate_pdfa_uses_user_jpeg_quality(outdir):
+    with (
+        patch('ocrmypdf._exec.ghostscript.version', return_value=Version('10.05.1')),
+        patch('ocrmypdf._exec.ghostscript.run_polling_stderr') as run_mock,
+    ):
+        run_mock.return_value = subprocess.CompletedProcess(
+            ['gs'], returncode=0, stdout='', stderr=''
+        )
+        ghostscript.generate_pdfa(
+            pdf_pages=[outdir / 'input.pdf'],
+            output_file=outdir / 'out.pdf',
+            compression='jpeg',
+            color_conversion_strategy='RGB',
+            jpeg_quality=72,
+        )
+
+    args = run_mock.call_args.args[0]
+    assert '-dJPEGQ=72' in args
+    assert '-dJPEGQ=95' not in args
+
+
+def test_generate_pdfa_jpeg_quality_zero_is_max_compression(outdir):
+    """Explicit jpeg_quality=0 must reach Ghostscript as -dJPEGQ=0.
+
+    Ghostscript accepts 0 as a valid quality value (maximum compression);
+    it must not be silently replaced by the default 95.
+    """
+    with (
+        patch('ocrmypdf._exec.ghostscript.version', return_value=Version('10.05.1')),
+        patch('ocrmypdf._exec.ghostscript.run_polling_stderr') as run_mock,
+    ):
+        run_mock.return_value = subprocess.CompletedProcess(
+            ['gs'], returncode=0, stdout='', stderr=''
+        )
+        ghostscript.generate_pdfa(
+            pdf_pages=[outdir / 'input.pdf'],
+            output_file=outdir / 'out.pdf',
+            compression='jpeg',
+            color_conversion_strategy='RGB',
+            jpeg_quality=0,
+        )
+
+    args = run_mock.call_args.args[0]
+    assert '-dJPEGQ=0' in args
+    assert '-dJPEGQ=95' not in args
+
+
+def test_generate_pdfa_honors_jpeg_maxdpi(outdir):
+    with (
+        patch('ocrmypdf._exec.ghostscript.version', return_value=Version('10.05.1')),
+        patch('ocrmypdf._exec.ghostscript.run_polling_stderr') as run_mock,
+    ):
+        run_mock.return_value = subprocess.CompletedProcess(
+            ['gs'], returncode=0, stdout='', stderr=''
+        )
+        ghostscript.generate_pdfa(
+            pdf_pages=[outdir / 'input.pdf'],
+            output_file=outdir / 'out.pdf',
+            compression='auto',
+            color_conversion_strategy='LeaveColorUnchanged',
+            jpeg_maxdpi=300,
+        )
+
+    args = run_mock.call_args.args[0]
+    assert '-dJPEGQ=95' in args
+    assert '-dDownsampleColorImages=true' in args
+    assert '-dColorImageDownsampleThreshold=1.0' in args
+    assert '-dDownsampleGrayImages=true' in args
+    assert '-dGrayImageDownsampleThreshold=1.0' in args
+    assert '-dDownsampleMonoImages=true' in args
+    assert '-dMonoImageDownsampleThreshold=1.0' in args
+    assert '-dColorImageResolution=300' in args
+    assert '-dGrayImageResolution=300' in args
+    assert '-dMonoImageResolution=300' in args
+
+
+def test_ghostscript_jpeg_options_via_cli(resources, outpdf):
+    """End-to-end: CLI flags reach the ghostscript plugin namespace."""
+    with patch(
+        'ocrmypdf._exec.ghostscript.generate_pdfa',
+        wraps=ghostscript.generate_pdfa,
+    ) as gen_mock:
+        run_ocrmypdf_api(
+            resources / 'francais.pdf',
+            outpdf,
+            '--output-type',
+            'pdfa',
+            '--ghostscript-jpeg-quality',
+            '60',
+            '--ghostscript-jpeg-maxdpi',
+            '150',
+            '--plugin',
+            'tests/plugins/tesseract_noop.py',
+        )
+    assert gen_mock.called
+    call_kwargs = gen_mock.call_args.kwargs
+    assert call_kwargs['jpeg_quality'] == 60
+    assert call_kwargs['jpeg_maxdpi'] == 150
+
+
 def test_gs_render_failure(resources, outpdf, caplog):
     exitcode = run_ocrmypdf_api(
         resources / 'blank.pdf',
@@ -176,9 +299,9 @@ def test_ghostscript_pdfa_failure(resources, outpdf, caplog):
         '--plugin',
         'tests/plugins/gs_pdfa_failure.py',
     )
-    assert (
+    assert exitcode == ExitCode.pdfa_conversion_failed, (
-        exitcode == ExitCode.pdfa_conversion_failed
+        "Unexpected return when PDF/A fails"
-    ), "Unexpected return when PDF/A fails"
+    )
 
 
 def test_ghostscript_feature_elision(resources, outpdf):
@@ -439,7 +562,9 @@ class TestGs106JpegCorruptionRepair:
                     repaired_bytes_list.append(obj.read_raw_bytes())
 
         assert len(repaired_bytes_list) == len(original_bytes_list)
-        for orig, repaired_bytes in zip(original_bytes_list, repaired_bytes_list, strict=False):
+        for orig, repaired_bytes in zip(
+            original_bytes_list, repaired_bytes_list, strict=False
+        ):
             assert orig == repaired_bytes, "Repaired bytes should match original"
 
         # Check that error/warning was logged

tests/test_optimize.py

@@ -215,6 +215,46 @@ def test_find_formx(resources):
         assert pagenos[xref] == 0
 
 
+def test_find_formx_circular_reference(resources, tmp_path, caplog):
+    """Regression for issue #1321.
+
+    Some PDFs (notably PowerPoint exports) contain Form XObjects that
+    reference themselves or each other in a cycle. The recursion guard in
+    _find_image_xrefs_container only deduplicates *image* xrefs, so a Form
+    XObject cycle would re-enter every branch until the depth limit fired,
+    producing thousands of "Recursion depth exceeded" warnings (and minutes
+    of wall-clock time on real-world inputs).
+    """
+    import logging
+
+    src = resources / 'formxobject.pdf'
+    out = tmp_path / 'circular_form.pdf'
+    with pikepdf.open(src) as pdf:
+        # /Form1 lives at xref 10. Replace its Resources.XObject with three
+        # entries that all point back to /Form1 itself, creating a fan-out
+        # cycle of branching factor 3.
+        form = pdf.pages[0].obj.Resources.XObject.Form1
+        form.Resources.XObject = Dictionary(
+            {'/Fm0': form, '/Fm1': form, '/Fm2': form}
+        )
+        pdf.save(out)
+
+    caplog.set_level(logging.WARNING, logger='ocrmypdf.optimize')
+    with pikepdf.open(out) as pdf:
+        opt._find_image_xrefs(pdf)
+
+    n_warnings = sum(
+        1
+        for r in caplog.records
+        if 'Recursion depth exceeded' in r.getMessage()
+    )
+    # Without the fix this is in the tens of thousands.
+    assert n_warnings == 0, (
+        f"Form XObject cycle should be detected without depth-limit warnings; "
+        f"got {n_warnings}"
+    )
+
+
 def test_extract_image_filter_with_pdf_image():
     image = Dictionary()
     image.Subtype = Name.Image

tests/test_page_numbers.py

@@ -42,6 +42,35 @@ def test_pages(pages, result):
         assert _pages_from_ranges(pages) == result
 
 
+@pytest.mark.parametrize(
+    'pages, total_pages, result',
+    [
+        ['end', 10, {9}],
+        ['END', 10, {9}],
+        ['1-end', 3, {0, 1, 2}],
+        ['3-end', 5, {2, 3, 4}],
+        ['end-end', 7, {6}],
+        ['1,end', 4, {0, 3}],
+        ['2-4,end', 10, {1, 2, 3, 9}],
+        ['end,end,end', 5, {4}],
+        ['end-1', 5, BadArgsError],  # empty range when end > 1
+    ],
+)
+def test_pages_end_alias(pages, total_pages, result):
+    if isinstance(result, type):
+        with pytest.raises(result):
+            _pages_from_ranges(pages, total_pages=total_pages)
+    else:
+        assert _pages_from_ranges(pages, total_pages=total_pages) == result
+
+
+def test_end_alias_requires_total_pages():
+    with pytest.raises(BadArgsError, match="total page count"):
+        _pages_from_ranges('1-end')
+    with pytest.raises(BadArgsError, match="total page count"):
+        _pages_from_ranges('end')
+
+
 def test_nonmonotonic_warning(caplog):
     pages = _pages_from_ranges('1, 3, 2')
     assert pages == {0, 1, 2}
@@ -61,3 +90,33 @@ def test_limited_pages(multipage, outpdf):
     assert not pi.pages[0].has_text
     assert pi.pages[4].has_text
     assert pi.pages[5].has_text
+
+
+def test_limited_pages_end_alias(multipage, outpdf):
+    # multipage has 6 pages; 5-end == pages 5..6
+    ocrmypdf.ocr(
+        multipage,
+        outpdf,
+        pages='5-end',
+        optimize=0,
+        output_type='pdf',
+        plugins=['tests/plugins/tesseract_cache.py'],
+    )
+    pi = PdfInfo(outpdf)
+    assert not pi.pages[0].has_text
+    assert pi.pages[4].has_text
+    assert pi.pages[5].has_text
+
+
+def test_pages_end_alone(multipage, outpdf):
+    ocrmypdf.ocr(
+        multipage,
+        outpdf,
+        pages='end',
+        optimize=0,
+        output_type='pdf',
+        plugins=['tests/plugins/tesseract_cache.py'],
+    )
+    pi = PdfInfo(outpdf)
+    assert not pi.pages[0].has_text
+    assert pi.pages[5].has_text

tests/test_tesseract.py

@@ -128,7 +128,6 @@ def test_timeout(caplog):
         (b'Error in boxClipToRectangle', ''),
         (b'an unexpected error', 'an unexpected error'),
         (b'a dire warning', 'a dire warning'),
-        (b'read_params_file something', 'read_params_file'),
         (b'an innocent message', 'innocent'),
         (b'\x7f\x7f\x80innocent unicode failure', 'innocent'),
     ],
@@ -148,6 +147,13 @@ def test_tesseract_log_output_raises(caplog):
     assert 'not found' in caplog.text
 
 
+def test_tesseract_log_output_raises_on_missing_config(caplog):
+    with pytest.raises(tesseract.TesseractConfigError) as excinfo:
+        tesseract.tesseract_log_output(b"read_params_file: Can't open hocr")
+    assert 'hocr' in excinfo.value.args[0]
+    assert 'read_params_file' in caplog.text
+
+
 def test_blocked_language(resources, no_outpdf):
     infile = resources / 'masks.pdf'
     for bad_lang in ['osd', 'equ']: