Fix page rotation regression

Page size fixes in commit b26749 did accounted for a "kept" rotation, but not a corrected rotation. Fixes #730.
2021-02-15 01:47:09 -08:00
parent 8770fff968
commit 064f935699
4 changed files with 169 additions and 4 deletions
@@ -584,7 +584,9 @@ def create_visible_page_jpg(image: Path, page_context: PageContext) -> Path:
    return output_file


-def create_pdf_page_from_image(image: Path, page_context: PageContext):
+def create_pdf_page_from_image(
+    image: Path, page_context: PageContext, orientation_correction
+):
    # We rasterize a square DPI version of each page because most image
    # processing tools don't support rectangular DPI. Use the square DPI as it
    # accurately describes the image. It would be possible to resample the image
@@ -595,7 +597,8 @@ def create_pdf_page_from_image(image: Path, page_context: PageContext):

    pageinfo = page_context.pageinfo
    pagesize = 72.0 * float(pageinfo.width_inches), 72.0 * float(pageinfo.height_inches)
-    if pageinfo.rotation % 180 == 90:
+    effective_rotation = (pageinfo.rotation - orientation_correction) % 360
+    if effective_rotation % 180 == 90:
        pagesize = pagesize[1], pagesize[0]

    # This create a single page PDF
@@ -607,6 +610,7 @@ def create_pdf_page_from_image(image: Path, page_context: PageContext):
            imfile, with_pdfrw=False, layout_fun=layout_fun, outputstream=pdf
        )
        log.debug('convert done')
+
    return output_file


@@ -204,7 +204,7 @@ def exec_page_sync(page_context: PageContext):
        if filtered_image:
            visible_image_out = filtered_image
        pdf_page_from_image_out = create_pdf_page_from_image(
-            visible_image_out, page_context
+            visible_image_out, page_context, orientation_correction
        )

    if options.pdf_renderer.startswith('hocr'):
@@ -0,0 +1,112 @@
+# © 2020 James R. Barlow: github.com/jbarlow83
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+"""Tesseract no-op/fixed rotate plugin
+
+To quickly run tests where getting OCR output is not necessary and we want to test
+the rotation pipeline.
+
+In 'hocr' mode, create a .hocr file that specifies no text found.
+
+In 'pdf' mode, convert the image to PDF using another program.
+
+In orientation check mode, report 0, 90, 180, 270... based on page number.
+"""
+
+import pikepdf
+from PIL import Image
+
+from ocrmypdf import OcrEngine, OrientationConfidence, hookimpl
+from ocrmypdf.helpers import page_number
+
+HOCR_TEMPLATE = '''<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
+    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
+ <head>
+  <title></title>
+  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+  <meta name='ocr-system' content='tesseract 4.0.0' />
+  <meta name='ocr-capabilities' content='ocr_page ocr_carea ocr_par ocr_line ocrx_word'/>
+ </head>
+ <body>
+  <div class='ocr_page' id='page_1' title='image "x.tif"; bbox 0 0 {0} {1}; ppageno 0'>
+   <div class='ocr_carea' id='block_1_1' title="bbox 0 1 {0} {1}">
+    <p class='ocr_par' dir='ltr' id='par_1' title="bbox 0 1 {0} {1}">
+     <span class='ocr_line' id='line_1' title="bbox 0 1 {0} {1}"><span class='ocrx_word' id='word_1' title="bbox 0 1 {0} {1}"> </span>
+     </span>
+    </p>
+   </div>
+  </div>
+ </body>
+</html>'''
+
+
+class FixedRotateNoopOcrEngine(OcrEngine):
+    @staticmethod
+    def version():
+        return '4.0.0'
+
+    @staticmethod
+    def creator_tag(options):
+        tag = '-PDF' if options.pdf_renderer == 'sandwich' else ''
+        return f"NO-OP {tag} {FixedRotateNoopOcrEngine.version()}"
+
+    def __str__(self):
+        return f"NO-OP {FixedRotateNoopOcrEngine.version()}"
+
+    @staticmethod
+    def languages(options):
+        return {'eng'}
+
+    @staticmethod
+    def get_orientation(input_file, options):
+        page = page_number(input_file)
+
+        angle = ((page - 1) * 90) % 360
+
+        return OrientationConfidence(angle=angle, confidence=99.9)
+
+    @staticmethod
+    def generate_hocr(input_file, output_hocr, output_text, options):
+        with Image.open(input_file) as im, open(
+            output_hocr, 'w', encoding='utf-8'
+        ) as f:
+            w, h = im.size
+            f.write(HOCR_TEMPLATE.format(str(w), str(h)))
+        with open(output_text, 'w') as f:
+            f.write('')
+
+    @staticmethod
+    def generate_pdf(input_file, output_pdf, output_text, options):
+        with Image.open(input_file) as im:
+            dpi = im.info['dpi']
+            pagesize = im.size[0] / dpi[0], im.size[1] / dpi[1]
+        ptsize = pagesize[0] * 72, pagesize[1] * 72
+        pdf = pikepdf.new()
+        pdf.add_blank_page(page_size=ptsize)
+        pdf.save(output_pdf, static_id=True)
+        output_text.write_text('')
+
+
+@hookimpl
+def get_ocr_engine():
+    return FixedRotateNoopOcrEngine()
@@ -6,15 +6,17 @@


 from io import BytesIO
+from math import cos, pi, sin
 from os import fspath

 import img2pdf
 import pikepdf
 import pytest
 from PIL import Image
+from reportlab.pdfgen.canvas import Canvas

 from ocrmypdf import leptonica
-from ocrmypdf._exec import ghostscript, tesseract
+from ocrmypdf._exec import ghostscript
 from ocrmypdf._plugin_manager import get_plugin_manager
 from ocrmypdf.helpers import Resolution
 from ocrmypdf.pdfinfo import PdfInfo
@@ -277,3 +279,50 @@ def test_rasterize_rotates(resources, tmp_path):
        filter_vector=False,
    )
    assert Image.open(img).size == (151, 123), "Image not rotated"
+
+
+def test_simulated_scan(outdir):
+    canvas = Canvas(
+        fspath(outdir / 'fakescan.pdf'),
+        pagesize=(209.8, 297.6),
+    )
+
+    page_vars = [(2, 36, 250), (91, 170, 240), (179, 190, 36), (271, 36, 36)]
+
+    for n, page_var in enumerate(page_vars):
+        text = canvas.beginText()
+        text.setFont('Helvetica', 20)
+
+        angle, x, y = page_var
+        cos_a, sin_a = cos(angle / 180.0 * pi), sin(angle / 180.0 * pi)
+
+        text.setTextTransform(cos_a, -sin_a, sin_a, cos_a, x, y)
+        text.textOut(f'Page {n + 1}')
+        canvas.drawText(text)
+        canvas.showPage()
+    canvas.save()
+
+    check_ocrmypdf(
+        outdir / 'fakescan.pdf',
+        outdir / 'out.pdf',
+        '--force-ocr',
+        '--deskew',
+        '--rotate-pages',
+        '--plugin',
+        'tests/plugins/tesseract_debug_rotate.py',
+    )
+
+    with pikepdf.open(outdir / 'out.pdf') as pdf:
+        assert (
+            pdf.pages[1].MediaBox[2] > pdf.pages[1].MediaBox[3]
+        ), "Wrong orientation: not landscape"
+        assert (
+            pdf.pages[3].MediaBox[2] > pdf.pages[3].MediaBox[3]
+        ), "Wrong orientation: Not landscape"
+
+        assert (
+            pdf.pages[0].MediaBox[2] < pdf.pages[0].MediaBox[3]
+        ), "Wrong orientation: Not portrait"
+        assert (
+            pdf.pages[2].MediaBox[2] < pdf.pages[2].MediaBox[3]
+        ), "Wrong orientation: Not portrait"