Remove unpaper from macOS build

Homebrew seems to be having issues with its deps?

azure-pipelines.yml

@@ -149,12 +149,6 @@ stages:
       - job: "macOS_Mojave"
         pool:
           vmImage: "macos-10.14"
-        strategy:
-          matrix:
-            Python37:
-              python.version: ""
-            Python38:
-              python.version: "python@3.8"
         steps:
           # https://github.com/actions/virtual-environments/issues/664
           # - task: UsePythonVersion@0
@@ -163,11 +157,8 @@ stages:
           - bash: |
               brew update
               brew unlink python@2
-              if [ "$(python.version)" != "" ]; then
+              brew upgrade python
-                brew upgrade $(python.version)
+              echo "Using Python `python3 --version`"
-              else
-                echo "Using Python `python3 --version`"
-              fi
             displayName: "Update brew and Python"
           - bash: |
               brew install \
@@ -177,8 +168,7 @@ stages:
                 leptonica \
                 openjpeg \
                 pngquant \
-                tesseract \
+                tesseract
-                unpaper
             displayName: "Install system packages"
           - bash: |
               pip3 install --upgrade pip

docs/release_notes.rst

@@ -12,6 +12,21 @@ may be unreliable. Use the API to depend on precise behavior.
 The public API may be useful in scripts that launch OCRmyPDF processes or that
 wish to use some of its features for working with PDFs.
 
+v11.1.0
+=======
+
+-  Fixed page rotation issues: #634, #589.
+-  Fixed some cases where optimization created an invalid image such as a
+   1-bit "RGB" iamge: #629, #620.
+-  Page numbers are now displayed in debug logs when pages are being grafted.
+-  ocrmypdf.optimize.rewrite_png and ocrmypdf.optimize.rewrite_png_as_g4 were
+   marked deprecated. Strictly speaking these should have been internal APIs,
+   but they were never hidden.
+-  As a precaution, pikepdf mmap-based file access has been disabled due to a
+   rare race condition that causes a crash when certain objects are deallocated.
+   The problem is likely in pikepdf's dependency pybind11.
+-  Extended the example plugin to demonstrate conversion to mono.
+
 v11.0.2
 =======
 

misc/example_plugin.py

@@ -30,6 +30,7 @@ log = logging.getLogger(__name__)
 @hookimpl
 def add_options(parser):
     parser.add_argument('--grayscale-ocr', action='store_true')
+    parser.add_argument('--mono-page', action='store_true')
 
 
 @hookimpl
@@ -52,7 +53,13 @@ def filter_ocr_image(page, image):
 
 @hookimpl
 def filter_page_image(page, image_filename):
-    output = image_filename.with_suffix('.jpg')
+    if page.options.mono_page:
-    with Image.open(image_filename) as im:
+        with Image.open(image_filename) as im:
-        im.save(output)
+            im = im.convert('1')
-    return output
+            im.save(image_filename)
+        return image_filename
+    else:
+        output = image_filename.with_suffix('.jpg')
+        with Image.open(image_filename) as im:
+            im.save(output)
+        return output

src/ocrmypdf/_graft.py

@@ -109,7 +109,6 @@ class OcrGrafter:
         if textpdf and not self.font:
             self.font, self.font_key = self._find_font(textpdf)
 
-        emplaced_page = False
         content_rotation = self.pdfinfo[pageno].rotation
         path_image = Path(image).resolve() if image else None
         if path_image is not None and path_image != self.path_base:
@@ -123,17 +122,21 @@ class OcrGrafter:
                 local_image_page = self.pdf_base.pages[-1]
                 self.pdf_base.pages[pageno].emplace(local_image_page)
                 del self.pdf_base.pages[-1]
-            emplaced_page = True
+            # The pdf_image_page will always be created with any /Rotate applied
+            # applied already
+            content_rotation = 0
 
-        if emplaced_page:
+        if content_rotation != 0:
-            content_rotation = autorotate_correction
+            # Text can be misaligned on a /Rotate'd page.
-        text_rotation = autorotate_correction
+            # That is because we rasterize pages with /Rotate applied,
-        text_misaligned = (text_rotation - content_rotation) % 360
+            # so that the OCR image text is upright and comes back upright.
-        log.debug(
+            text_misaligned = (autorotate_correction - content_rotation) % 360
-            f"Rotations for page {pageno}: [text, auto, misalign, content] = "
+            log.debug(
-            f"{text_rotation}, {autorotate_correction}, "
+                f"Text rotation: (autorotate, content) -> text misalignment = "
-            f"{text_misaligned}, {content_rotation}"
+                f"({autorotate_correction}, {content_rotation}) -> {text_misaligned}"
-        )
+            )
+        else:
+            text_misaligned = 0
 
         if textpdf and self.font:
             # Graft the text layer onto this page, whether new or old
@@ -143,15 +146,18 @@ class OcrGrafter:
                 textpdf=textpdf,
                 font=self.font,
                 font_key=self.font_key,
-                rotation=text_misaligned,
+                text_rotation=text_misaligned,
                 procset=self.procset,
                 strip_old_text=strip_old,
             )
 
-        # Correct the rotation if applicable
+        # Correct the page rotation
-        self.pdf_base.pages[pageno].Rotate = (
+        page_rotation = (content_rotation - autorotate_correction) % 360
-            content_rotation - autorotate_correction
+        self.pdf_base.pages[pageno].Rotate = page_rotation
-        ) % 360
+        log.debug(
+            f"Page rotation: (content, auto) -> page = "
+            f"({content_rotation}, {autorotate_correction}) -> {page_rotation}"
+        )
 
         if self.emplacements % MAX_REPLACE_PAGES == 0:
             self.save_and_reload()
@@ -226,7 +232,7 @@ class OcrGrafter:
         font: pikepdf.Object,
         font_key: pikepdf.Object,
         procset: pikepdf.Object,
-        rotation: int,
+        text_rotation: int,
         strip_old_text: bool,
     ):
         """Insert the text layer from text page 0 on to pdf_base at page_num"""
@@ -256,13 +262,13 @@ class OcrGrafter:
             corner = pikepdf.PdfMatrix().translated(mediabox[0], mediabox[1])
             # -rotation because the input is a clockwise angle and this formula
             # uses CCW
-            rotation = -rotation % 360
+            text_rotation = -text_rotation % 360
-            rotate = pikepdf.PdfMatrix().rotated(rotation)
+            rotate = pikepdf.PdfMatrix().rotated(text_rotation)
 
             # Because of rounding of DPI, we might get a text layer that is not
             # identically sized to the target page. Scale to adjust. Normally this
             # is within 0.998.
-            if rotation in (90, 270):
+            if text_rotation in (90, 270):
                 wt, ht = ht, wt
             scale_x = wp / wt
             scale_y = hp / ht

src/ocrmypdf/_sync.py

@@ -252,15 +252,19 @@ def exec_concurrent(context: PdfContext):
     ocrgraft = OcrGrafter(context)
 
     def update_page(result: PageResult, pbar):
-        sidecars[result.pageno] = result.text
+        try:
-        pbar.update()
+            tls.pageno = result.pageno + 1
-        ocrgraft.graft_page(
+            sidecars[result.pageno] = result.text
-            pageno=result.pageno,
+            pbar.update()
-            image=result.pdf_page_from_image,
+            ocrgraft.graft_page(
-            textpdf=result.ocr,
+                pageno=result.pageno,
-            autorotate_correction=result.orientation_correction,
+                image=result.pdf_page_from_image,
-        )
+                textpdf=result.ocr,
-        pbar.update()
+                autorotate_correction=result.orientation_correction,
+            )
+            pbar.update()
+        finally:
+            tls.pageno = None
 
     exec_progress_pool(
         use_threads=context.options.use_threads,

src/ocrmypdf/_validation.py

@@ -308,17 +308,6 @@ def check_closed_streams(options):  # pragma: no cover
     return True
 
 
-def log_page_orientations(pdfinfo):
-    direction = {0: 'n', 90: 'e', 180: 's', 270: 'w'}
-    orientations = []
-    for n, page in enumerate(pdfinfo):
-        angle = page.rotation or 0
-        if angle != 0:
-            orientations.append('{0}{1}'.format(n + 1, direction.get(angle, '')))
-    if orientations:
-        log.info('Page orientations detected: %s', ' '.join(orientations))
-
-
 def create_input_file(options, work_folder: Path) -> Tuple[Path, str]:
     if options.input_file == '-':
         # stdin

src/ocrmypdf/helpers.py

@@ -213,11 +213,15 @@ def clamp(n: T, smallest: T, largest: T) -> T:
 
 
 def pikepdf_enable_mmap():
-    try:
+    # try:
-        if pikepdf._qpdf.set_access_default_mmap(True):
+    #     if pikepdf._qpdf.set_access_default_mmap(True):
-            log.debug("pikepdf mmap enabled")
+    #         log.debug("pikepdf mmap enabled")
-    except AttributeError:
+    # except AttributeError:
-        log.debug("pikepdf mmap not available")
+    #     log.debug("pikepdf mmap not available")
+    # We found a race condition probably related to pybind issue #2252 that can
+    # cause a crash. For now, disable pikepdf mmap to be on the safe side.
+    log.debug("pikepdf mmap disabled")
+    return
 
 
 def deprecated(func):

src/ocrmypdf/leptonica.py

@@ -58,6 +58,24 @@ if not _libpath:
         ---------------------------------------------------------------------
         """
     )
+if os.name == 'nt':  
+    # On Windows, recent versions of libpng require zlib. We have to make sure 
+    # the zlib version being loaded is the same one that libpng was built with. 
+    # This tries to import zlib from Tesseract's installation folder, falling back
+    # to find_library() if liblept is being loaded from somewhere else.
+    # Loading zlib from other places could cause a version mismatch
+    _zlib_path = os.path.join(os.path.dirname(_libpath), 'zlib1.dll')
+    if not os.path.exists(_zlib_path):
+        _zlib_path = find_library('zlib')
+    try:
+        zlib = ffi.dlopen(_zlib_path)
+    except ffi.error as e:
+        raise MissingDependencyError(
+            """
+            Could not load the zlib library. It could be that Tesseract is not installed properly,
+            we can't find the installation on your system PATH environment variable.
+            """
+        ) from e
 try:
     lept = ffi.dlopen(_libpath)
     lept.setMsgSeverity(lept.L_SEVERITY_WARNING)

src/ocrmypdf/optimize.py

@@ -10,6 +10,7 @@ import sys
 import tempfile
 from collections import defaultdict
 from functools import partial
+from io import BytesIO
 from os import fspath
 from pathlib import Path
 from typing import (
@@ -27,6 +28,7 @@ from typing import (
     Union,
 )
 
+import img2pdf
 import pikepdf
 from pikepdf import Dictionary, Name, Object, Pdf, PdfImage
 from PIL import Image
@@ -37,7 +39,7 @@ from ocrmypdf._concurrent import exec_progress_pool
 from ocrmypdf._exec import jbig2enc, pngquant
 from ocrmypdf._jobcontext import PdfContext
 from ocrmypdf.exceptions import OutputFileAccessError
-from ocrmypdf.helpers import safe_symlink
+from ocrmypdf.helpers import deprecated, safe_symlink
 
 log = logging.getLogger(__name__)
 
@@ -393,6 +395,30 @@ def transcode_jpegs(pike: Pdf, jpegs: Sequence[Xref], root: Path, options) -> No
         im_obj.write(compdata.read(), filter=Name.DCTDecode)
 
 
+def _transcode_png(pike: Pdf, filename: Path, xref: Xref) -> bool:
+    output = filename.with_suffix('.png.pdf')
+    with output.open('wb') as f:
+        img2pdf.convert(fspath(filename), outputstream=f)
+
+    with pikepdf.open(output) as pdf_image:
+        foreign_image = next(pdf_image.pages[0].images.values())
+        local_image = pike.copy_foreign(foreign_image)
+
+        im_obj = pike.get_object(xref, 0)
+        im_obj.write(
+            local_image.read_raw_bytes(),
+            filter=local_image.Filter,
+            decode_parms=local_image.DecodeParms,
+        )
+
+        del_keys = set(im_obj.keys()) - set(local_image.keys())
+        for key in local_image.keys():
+            if key != Name.Length:
+                im_obj[key] = local_image[key]
+        for key in del_keys:
+            del im_obj[key]
+
+
 def transcode_pngs(
     pike: Pdf,
     images: Sequence[Xref],
@@ -435,34 +461,11 @@ def transcode_pngs(
         )
 
     for xref in modified:
-        im_obj = pike.get_object(xref, 0)
+        filename = png_name(root, xref)
-        try:
+        _transcode_png(pike, filename, xref)
-            pix = leptonica.Pix.open(png_name(root, xref))
-            if pix.mode == '1':
-                compdata = pix.generate_pdf_ci_data(leptonica.lept.L_G4_ENCODE, 0)
-            else:
-                compdata = leptonica.CompressedData.open(png_name(root, xref))
-        except leptonica.LeptonicaError as e:
-            # Most likely this means file not found, i.e. quantize did not
-            # produce an improved version
-            log.error(e)
-            continue
-
-        # If re-coded image is larger don't use it - we test here because
-        # pngquant knows the size of the temporary output file but not the actual
-        # object in the PDF
-        if len(compdata) > int(im_obj.stream_dict.Length):
-            log.debug(
-                f"pngquant: pngquant did not improve over original image "
-                f"{len(compdata)} > {int(im_obj.stream_dict.Length)}"
-            )
-            continue
-        if compdata.type == leptonica.lept.L_FLATE_ENCODE:
-            rewrite_png(pike, im_obj, compdata)
-        elif compdata.type == leptonica.lept.L_G4_ENCODE:
-            rewrite_png_as_g4(pike, im_obj, compdata)
 
 
+@deprecated
 def rewrite_png_as_g4(pike: Pdf, im_obj: Object, compdata) -> None:
     im_obj.BitsPerComponent = 1
     im_obj.Width = compdata.w
@@ -483,6 +486,7 @@ def rewrite_png_as_g4(pike: Pdf, im_obj: Object, compdata) -> None:
     return
 
 
+@deprecated
 def rewrite_png(pike: Pdf, im_obj: Object, compdata) -> None:
     # When a PNG is inserted into a PDF, we more or less copy the IDAT section from
     # the PDF and transfer the rest of the PNG headers to PDF image metadata.

src/ocrmypdf/pluginspec.py

@@ -154,11 +154,29 @@ def filter_page_image(page: 'PageContext', image_filename: Path) -> Path:
     produced for a given page, this function will not be called. This is not
     the image that will be shown to OCR.
 
-    ocrmypdf will create the PDF page based on the image format used. If you
+    If the function does not want to modify the image, it should return
+    ``image_filename``. The hook may overwrite ``image_filename`` with a new file.
+
+    The output image should preserve the same physical unit dimensions, that is
+    (width * dpi_x, height * dpi_y). That is, if the image is resized, the DPI
+    must be adjusted by the reciprocal. If this is not preserved, the PDF page
+    will be resized and the OCR layer misaligned. OCRmyPDF does not nothing
+    to enforce these constraints; it is up to the plugin to do sensible things.
+
+    OCRmyPDF will create the PDF page based on the image format used. If you
     convert the image to a JPEG, the output page will be created as a JPEG, etc.
-    Note that the ocrmypdf image optimization stage may ultimately chose a
+    If you change the colorspace, that change will be kept. Note that the
+    OCRmyPDF image optimization stage, if enabled, may ultimately chose a
     different format.
 
+    If the return value is a file that does not exist, ``FileNotFoundError``
+    will occur. The return value should be a path to a file in the same folder
+    as ``image_filename``.
+
+    Implementation detail: If the value returned is falsy, OCRmyPDF will ignore
+    the return value and assume the input file was unmodified. This is deprecated.
+    To leave the image unmodified, ``image_filename`` should be returned.
+
     Note:
         This hook will be called from child processes. Modifying global state
         will not affect the main process or other child processes.