v9.0.2 release notes

Previously we attempted to reinsert all PNGs, but it appears to be
unlikely that Leptonica's API is actually capable of optimizing the PNG
before it inserts it.

In any event qpdf has gained image optimization capabilities as well
which we coudld borrow.

.docker/alpine.dockerfile

@@ -14,7 +14,7 @@ RUN \
   && apk add --update \
   python3-dev \
   py3-setuptools \
-  jbig2enc@testing \
+  jbig2enc@community \
   ghostscript \
   qpdf@community \
   qpdf-dev@community \

.travis.yml

@@ -127,7 +127,7 @@ script:
 
 deploy:
   # release for main pypi
-  # 3.6 is considered the build leader and does the deploy, otherwise there is
+  # 3.7 is considered the build leader and does the deploy, otherwise there is
   # a race and all versions will try to deploy
   # OTOH if we ever need separate binary wheels then each version needs its
   # own deploy
@@ -139,5 +139,5 @@ deploy:
     on:
       branch: master
       tags: true
-      condition: $TRAVIS_PYTHON_VERSION == "3.6" && $TRAVIS_OS_NAME == "linux"
+      condition: $TRAVIS_PYTHON_VERSION == "3.7" && $TRAVIS_OS_NAME == "linux"
     skip_upload_docs: true

docs/cookbook.rst

@@ -165,8 +165,8 @@ might remove desirable content, especially from poor quality scans.
 -  ``--deskew`` will correct pages were scanned at a skewed angle by
    rotating them back into place. Skew determination and correction is
    performed using `Postl's variance of line
-   sums <http://www.leptonica.com/skew-measurement.html>`__ algorithm as
-   implemented in `Leptonica <http://www.leptonica.com/index.html>`__.
+   sums <http://www.leptonica.org/skew-measurement.html>`__ algorithm as
+   implemented in `Leptonica <http://www.leptonica.org/index.html>`__.
 -  ``--clean`` uses
    `unpaper <https://www.flameeyes.eu/projects/unpaper>`__ to clean up
    pages before OCR, but does not alter the final output. This makes it

docs/installation.rst

@@ -21,7 +21,7 @@ installing the Python binary wheels.
 Installing on Linux
 ===================
 
-Debian and Ubuntu 16.10 or newer
+Debian and Ubuntu 18.04 or newer
 --------------------------------
 
 .. |deb-stable| image:: https://repology.org/badge/version-for-repo/debian_stable/ocrmypdf.svg
@@ -33,27 +33,29 @@ Debian and Ubuntu 16.10 or newer
 .. |deb-unstable| image:: https://repology.org/badge/version-for-repo/debian_unstable/ocrmypdf.svg
     :alt: Debian unstable
 
-.. |ubu-1710| image:: https://repology.org/badge/version-for-repo/ubuntu_17_10/ocrmypdf.svg
-    :alt: Ubuntu 17.10
-
 .. |ubu-1804| image:: https://repology.org/badge/version-for-repo/ubuntu_18_04/ocrmypdf.svg
     :alt: Ubuntu 18.04 LTS
 
 .. |ubu-1810| image:: https://repology.org/badge/version-for-repo/ubuntu_18_10/ocrmypdf.svg
     :alt: Ubuntu 18.10
 
+.. |ubu-1904| image:: https://repology.org/badge/version-for-repo/ubuntu_19_04/ocrmypdf.svg
+    :alt: Ubuntu 19.04
 
-+-------------------------------------------+
-| **OCRmyPDF versions in Debian & Ubuntu**  |
-+-------------------------------------------+
-| |latest|                                  |
-+-------------------------------------------+
-| |deb-stable| |deb-testing| |deb-unstable| |
-+-------------------------------------------+
-| |ubu-1710| |ubu-1804| |ubu-1810|          |
-+-------------------------------------------+
+.. |ubu-1910| image:: https://repology.org/badge/version-for-repo/ubuntu_19_10/ocrmypdf.svg
+    :alt: Ubuntu 19.10
 
-Users of Debian 9 ("stretch") or later or Ubuntu 16.10 or later may
++-----------------------------------------------+
+| **OCRmyPDF versions in Debian & Ubuntu**      |
++-----------------------------------------------+
+| |latest|                                      |
++-----------------------------------------------+
+| |deb-stable| |deb-testing| |deb-unstable|     |
++-----------------------------------------------+
+| |ubu-1804| |ubu-1810| |ubu-1904| |ubu-1910|   |
++-----------------------------------------------+
+
+Users of Debian 9 ("stretch") or later or Ubuntu 18.04 or later may
 simply
 
 .. code-block:: bash
@@ -64,7 +66,8 @@ As indicated in the table above, Debian and Ubuntu releases may lag
 behind the latest version. If the version available for your platform is
 out of date, you could opt to install the latest version from source.
 See `Installing HEAD revision from
-sources <#installing-head-revision-from-sources>`__.
+sources <#installing-head-revision-from-sources>`__. Ubuntu 16.10 to 17.10
+inclusive also had ocrmypdf, but these versions are end of life.
 
 For full details on version availability for your platform, check the
 `Debian Package Tracker <https://tracker.debian.org/pkg/ocrmypdf>`__ or
@@ -81,19 +84,22 @@ For full details on version availability for your platform, check the
 Fedora 29 or newer
 ------------------
 
-.. |fedora-29| image:: https://repology.org/badge/version-for-repo/fedora29/ocrmypdf.svg
+.. |fedora-29| image:: https://repology.org/badge/version-for-repo/fedora_29/ocrmypdf.svg
     :alt: Fedora 29
 
+.. |fedora-30| image:: https://repology.org/badge/version-for-repo/fedora_30/ocrmypdf.svg
+    :alt: Fedora 30
+
 .. |fedora-rawhide| image:: https://repology.org/badge/version-for-repo/fedora_rawhide/ocrmypdf.svg
     :alt: Fedore Rawhide
 
-+------------------------------+
-| **OCRmyPDF version**         |
-+------------------------------+
-| |latest|                     |
-+------------------------------+
-| |fedora-29| |fedora-rawhide| |
-+------------------------------+
++-----------------------------------------------+
+| **OCRmyPDF version**                          |
++-----------------------------------------------+
+| |latest|                                      |
++-----------------------------------------------+
+| |fedora-29| |fedora-30| |fedora-rawhide|      |
++-----------------------------------------------+
 
 Users of Fedora 29 later may simply
 
@@ -507,7 +513,7 @@ manager. ``pip`` cannot provide them.
 -  Python 3.6 or newer
 -  Ghostscript 9.15 or newer
 -  qpdf 8.1.0 or newer
--  Tesseract 4.0.0-alpha or newer
+-  Tesseract 4.0.0-beta or newer
 
 As of ocrmypdf 7.2.1, the following versions are recommended:
 

docs/release_notes.rst

@@ -13,14 +13,31 @@ Note that it is licensed under GPLv3, so scripts that
 ``import ocrmypdf`` and are released publicly should probably also be
 licensed under GPLv3.
 
+v9.0.2
+======
+
+-  The image optimizer now skips optimizing flate (PNG) encoded images in some
+   situations where the optimization effort was likely wasted.
+-  The image optimizer now ignores images that specify arbitrary decode arrays,
+   since these are rare.
+-  Fixed an issue that caused inversion of black and white in monochrome images.
+   We are not certain but the problem seems to be linked to Leptonica 1.76.0 and
+   older.
+-  Fixed some cases where the test suite failed or produced unexpected if
+   English or German Tesseract language packs were not installed.
+-  Fixed a runtime error if the Tesseract English language is not installed.
+-  Improved explicit closing of Pillow images after use.
+-  Actually fixed of Alpine Docker image build.
+-  Changed to pikepdf 1.6.3.
+
 v9.0.1
 ======
 
 -  Fixed test suite failing when either of optional dependencies unpaper and
    pngquant were missing.
--  Fixed Alpine Docker image build.
+-  Attempted fix of Alpine Docker image build.
 -  Documented that FreeBSD ports are now available.
--  Changed to pikepdf 1.6.1 (also for Alpine Docker).
+-  Changed to pikepdf 1.6.1.
 
 v9.0.0
 ======

requirements/test.txt

@@ -1,6 +1,6 @@
-pytest >= 4.4.1, < 5
+pytest >= 5.0.0
 pytest-helpers-namespace >= 2019.1.8
-pytest-xdist == 1.28.0
+pytest-xdist >= 1.29.0  # For DumpError fix
 pytest-cov >= 2.6.1
 python-xmp-toolkit   # requires apt-get install libexempi3
                      # or brew install exempi

src/ocrmypdf/_pipeline.py

@@ -54,9 +54,9 @@ def triage_image_file(input_file, output_file, options, log):
         # Recover the original filename
         log.error(str(e).replace(input_file, options.input_file))
         raise UnsupportedImageFormatError() from e
-    else:
-        log.info("Input file is an image")
 
+    with im:
+        log.info("Input file is an image")
         if 'dpi' in im.info:
             if im.info['dpi'] <= (96, 96) and not options.image_dpi:
                 log.info("Image size: (%d, %d)" % im.size)
@@ -89,7 +89,6 @@ def triage_image_file(input_file, output_file, options, log):
             elif im.mode == 'CMYK':
                 log.info('Input CMYK image has no ICC profile, not usable')
                 raise UnsupportedImageFormatError()
-        im.close()
 
     try:
         log.info("Image seems valid. Try converting to PDF...")

src/ocrmypdf/_validation.py

@@ -107,7 +107,7 @@ def check_options_output(options):
         options.pdf_renderer = 'sandwich'
 
     if options.pdf_renderer == 'sandwich' and not tesseract.has_textonly_pdf(
-        options.tesseract_env
+        options.tesseract_env, languages
     ):
         raise MissingDependencyError(
             "You are using an alpha version of Tesseract 4.0 that does not support "

src/ocrmypdf/exec/pngquant.py

@@ -40,8 +40,7 @@ def available():
 
 def quantize(input_file, output_file, quality_min, quality_max):
     if input_file.endswith('.jpg'):
-        im = Image.open(input_file)
-        with NamedTemporaryFile(suffix='.png') as tmp:
+        with Image.open(input_file) as im, NamedTemporaryFile(suffix='.png') as tmp:
             im.save(tmp)
             args = [
                 'pngquant',

src/ocrmypdf/exec/tesseract.py

@@ -61,13 +61,13 @@ def v4(tesseract_env=None):
     return version(tesseract_env) >= '4'
 
 
-def has_textonly_pdf(tesseract_env=None):
+def has_textonly_pdf(tesseract_env=None, langs=None):
     """Does Tesseract have textonly_pdf capability?
 
     Available in v4.00.00alpha since January 2017. Best to
-    parse the parameter list
+    parse the parameter list.
     """
-    args_tess = ['tesseract', '--print-parameters', 'pdf']
+    args_tess = tess_base_args(langs, engine_mode=None) + ['--print-parameters', 'pdf']
     params = ''
     try:
         proc = run(
@@ -233,8 +233,8 @@ def _generate_null_hocr(output_hocr, output_sidecar, image):
     the same size as the input image."""
     from PIL import Image
 
-    im = Image.open(image)
-    w, h = im.size
+    with Image.open(image) as im:
+        w, h = im.size
 
     with open(output_hocr, 'w', encoding="utf-8") as f:
         f.write(HOCR_TEMPLATE.format(w, h))
@@ -358,7 +358,7 @@ def generate_pdf(
     if pagesegmode is not None:
         args_tesseract.extend(['--psm', str(pagesegmode)])
 
-    if text_only and has_textonly_pdf(tesseract_env):
+    if text_only and has_textonly_pdf(tesseract_env, language):
         args_tesseract.extend(['-c', 'textonly_pdf=1'])
 
     if user_words:

src/ocrmypdf/exec/unpaper.py

@@ -42,33 +42,30 @@ def run(input_file, output_file, dpi, log, mode_args):
 
     SUFFIXES = {'1': '.pbm', 'L': '.pgm', 'RGB': '.ppm'}
 
-    im = Image.open(input_file)
-    if im.mode not in SUFFIXES.keys():
-        log.info("Converting image to other colorspace")
+    with TemporaryDirectory() as tmpdir, Image.open(input_file) as im:
+        if im.mode not in SUFFIXES.keys():
+            log.info("Converting image to other colorspace")
+            try:
+                if im.mode == 'P' and len(im.getcolors()) == 2:
+                    im = im.convert(mode='1')
+                else:
+                    im = im.convert(mode='RGB')
+            except IOError as e:
+                im.close()
+                raise MissingDependencyError(
+                    "Could not convert image with type " + im.mode
+                ) from e
+
         try:
-            if im.mode == 'P' and len(im.getcolors()) == 2:
-                im = im.convert(mode='1')
-            else:
-                im = im.convert(mode='RGB')
-        except IOError as e:
-            im.close()
+            suffix = SUFFIXES[im.mode]
+        except KeyError:
             raise MissingDependencyError(
-                "Could not convert image with type " + im.mode
+                "Failed to convert image to a supported format."
             ) from e
 
-    try:
-        suffix = SUFFIXES[im.mode]
-    except KeyError:
-        im.close()
-        raise MissingDependencyError(
-            "Failed to convert image to a supported format."
-        ) from e
-
-    with TemporaryDirectory() as tmpdir:
         input_pnm = os.path.join(tmpdir, f'input{suffix}')
         output_pnm = os.path.join(tmpdir, f'output{suffix}')
         im.save(input_pnm, format='PPM')
-        im.close()
 
         # To prevent any shenanigans from accepting arbitrary parameters in
         # --unpaper-args, we:
@@ -95,10 +92,12 @@ def run(input_file, output_file, dpi, log, mode_args):
             log.debug(proc.stdout)
             # unpaper sets dpi to 72; fix this
             try:
-                Image.open(output_pnm).save(output_file, dpi=(dpi, dpi))
+                with Image.open(output_pnm) as imout:
+                    imout.save(output_file, dpi=(dpi, dpi))
             except (FileNotFoundError, OSError):
                 raise SubprocessOutputError(
-                    "unpaper: failed to produce the expected output file. Called with: "
+                    "unpaper: failed to produce the expected output file. "
+                    + " Called with: "
                     + str(args_unpaper)
                 ) from None
 

src/ocrmypdf/optimize.py

@@ -73,6 +73,9 @@ def extract_image_filter(pike, root, log, image, xref):
     if filtdp[0] == Name.JPXDecode:
         return None  # Don't do JPEG2000
 
+    if Name.Decode in image:
+        return None  # Don't mess with custom Decode tables
+
     return pim, filtdp
 
 
@@ -104,6 +107,10 @@ def extract_image_generic(*, pike, root, log, image, xref, options):
         return None
     pim, filtdp = result
 
+    # Don't try to PNG-optimize 1bpp images, since JBIG2 does it better.
+    if pim.bits_per_component == 1:
+        return None
+
     if filtdp[0] == Name.DCTDecode and options.optimize >= 2:
         # This is a simple heuristic derived from some training data, that has
         # about a 70% chance of guessing whether the JPEG is high quality,
@@ -343,6 +350,7 @@ def transcode_jpegs(pike, jpegs, root, log, options):
 
 
 def transcode_pngs(pike, images, image_name_fn, root, log, options):
+    modified = set()
     if options.optimize >= 2:
         png_quality = (
             max(10, options.png_quality - 10),
@@ -363,6 +371,7 @@ def transcode_pngs(pike, images, image_name_fn, root, log, options):
                         png_quality[1],
                     )
                 )
+                modified.add(xref)
             with tqdm(
                 desc="PNGs",
                 total=len(futures),
@@ -372,10 +381,14 @@ def transcode_pngs(pike, images, image_name_fn, root, log, options):
                 for _future in concurrent.futures.as_completed(futures):
                     pbar.update()
 
-    for xref in images:
+    for xref in modified:
         im_obj = pike.get_object(xref, 0)
         try:
-            compdata = leptonica.CompressedData.open(png_name(root, 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
@@ -391,62 +404,83 @@ def transcode_pngs(pike, images, image_name_fn, root, log, options):
                 f"{len(compdata)} > {int(im_obj.stream_dict.Length)}"
             )
             continue
+        if compdata.type == leptonica.lept.L_FLATE_ENCODE:
+            return rewrite_png(pike, im_obj, compdata, log)
+        elif compdata.type == leptonica.lept.L_G4_ENCODE:
+            return rewrite_png_as_g4(pike, im_obj, compdata, log)
 
-        # 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.
-        # One thing we have to do is tell the PDF reader whether a predictor was used
-        # on the image before Flate encoding. (Typically one is.)
-        # According to Leptonica source, PDF readers don't actually need us
-        # to specify the correct predictor, they just need a value of either:
-        #   1 - no predictor
-        #   10-14 - there is a predictor
-        # Leptonica's compdata->predictor only tells TRUE or FALSE
-        # From there the PNG decoder can infer the rest from the file.
-        # In practice the predictor should be Paeth, 14, so we'll use that.
-        # See:
-        #   - PDF RM 7.4.4.4 Table 10
-        #   - https://github.com/DanBloomberg/leptonica/blob/master/src/pdfio2.c#L757
-        predictor = 14 if compdata.predictor > 0 else 1
-        dparms = Dictionary(Predictor=predictor)
-        if predictor > 1:
-            dparms.BitsPerComponent = compdata.bps  # Yes, this is redundant
-            dparms.Colors = compdata.spp
-            dparms.Columns = compdata.w
 
-        im_obj.BitsPerComponent = compdata.bps
-        im_obj.Width = compdata.w
-        im_obj.Height = compdata.h
+def rewrite_png_as_g4(pike, im_obj, compdata, log):
+    im_obj.BitsPerComponent = 1
+    im_obj.Width = compdata.w
+    im_obj.Height = compdata.h
 
-        if compdata.ncolors > 0:
-            # .ncolors is the number of colors in the palette, not the number of
-            # colors used in a true color image
-            palette_pdf_string = compdata.get_palette_pdf_string()
-            palette_data = pikepdf.Object.parse(palette_pdf_string)
-            palette_stream = pikepdf.Stream(pike, bytes(palette_data))
-            palette = [
-                Name.Indexed,
-                Name.DeviceRGB,
-                compdata.ncolors - 1,
-                palette_stream,
-            ]
-            cs = palette
-        else:
-            if compdata.spp == 1:
-                # PDF interprets binary-1 as black in 1bpp, but PNG sets
-                # black to 0 for 1bpp. Create a palette that informs the PDF
-                # of the mapping - seems cleaner to go this way but pikepdf
-                # needs to be patched to support it.
-                # palette = [Name.Indexed, Name.DeviceGray, 1, b"\xff\x00"]
-                # cs = palette
-                cs = Name.DeviceGray
-            elif compdata.spp == 3:
-                cs = Name.DeviceRGB
-            elif compdata.spp == 4:
-                cs = Name.DeviceCMYK
-        if compdata.bps == 1:
-            im_obj.Decode = [1, 0]  # Bit of a kludge but this inverts photometric too
-        im_obj.ColorSpace = cs
-        im_obj.write(compdata.read(), filter=Name.FlateDecode, decode_parms=dparms)
+    im_obj.write(compdata.read())
+
+    log.debug(f"PNG to G4 {im_obj.objgen}")
+    if Name.Predictor in im_obj:
+        del im_obj.Predictor
+    if Name.DecodeParms in im_obj:
+        del im_obj.DecodeParms
+    im_obj.DecodeParms = Dictionary(
+        K=-1, BlackIs1=bool(compdata.minisblack), Columns=compdata.w
+    )
+
+    im_obj.Filter = Name.CCITTFaxDecode
+    return
+
+
+def rewrite_png(pike, im_obj, compdata, log):
+    # 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.
+    # One thing we have to do is tell the PDF reader whether a predictor was used
+    # on the image before Flate encoding. (Typically one is.)
+    # According to Leptonica source, PDF readers don't actually need us
+    # to specify the correct predictor, they just need a value of either:
+    #   1 - no predictor
+    #   10-14 - there is a predictor
+    # Leptonica's compdata->predictor only tells TRUE or FALSE
+    # 10-14 means the actual predictor is specified in the data, so for any
+    # number >= 10 the PDF reader will use whatever the PNG data specifies.
+    # In practice Leptonica should use Paeth, 14, but 15 seems to be the
+    # designated value for "optimal". So we will use 15.
+    # See:
+    #   - PDF RM 7.4.4.4 Table 10
+    #   - https://github.com/DanBloomberg/leptonica/blob/master/src/pdfio2.c#L757
+    predictor = 15 if compdata.predictor > 0 else 1
+    dparms = Dictionary(Predictor=predictor)
+    if predictor > 1:
+        dparms.BitsPerComponent = compdata.bps  # Yes, this is redundant
+        dparms.Colors = compdata.spp
+        dparms.Columns = compdata.w
+
+    im_obj.BitsPerComponent = compdata.bps
+    im_obj.Width = compdata.w
+    im_obj.Height = compdata.h
+
+    log.debug(
+        f"PNG {im_obj.objgen}: palette={compdata.ncolors} spp={compdata.spp} bps={compdata.bps}"
+    )
+    if compdata.ncolors > 0:
+        # .ncolors is the number of colors in the palette, not the number of
+        # colors used in a true color image. The palette string is always
+        # given as RGB tuples even when the image is grayscale; see
+        # https://github.com/DanBloomberg/leptonica/blob/master/src/colormap.c#L2067
+        palette_pdf_string = compdata.get_palette_pdf_string()
+        palette_data = pikepdf.Object.parse(palette_pdf_string)
+        palette_stream = pikepdf.Stream(pike, bytes(palette_data))
+        palette = [Name.Indexed, Name.DeviceRGB, compdata.ncolors - 1, palette_stream]
+        cs = palette
+    else:
+        # ncolors == 0 means we are using a colorspace without a palette
+        if compdata.spp == 1:
+            cs = Name.DeviceGray
+        elif compdata.spp == 3:
+            cs = Name.DeviceRGB
+        elif compdata.spp == 4:
+            cs = Name.DeviceCMYK
+    im_obj.ColorSpace = cs
+    im_obj.write(compdata.read(), filter=Name.FlateDecode, decode_parms=dparms)
 
 
 def optimize(input_file, output_file, context, save_settings):

tests/spoof/tesseract_badutf8.py

@@ -52,7 +52,7 @@ def main():
     elif sys.argv[1] == '--list-langs':
         print('List of available languages (1):\neng', file=sys.stderr)
         sys.exit(0)
-    elif sys.argv[1] == '--print-parameters':
+    elif sys.argv[-2] == '--print-parameters':
         print("Some parameters", file=sys.stderr)
         print("textonly_pdf\t1\tSome help text")
         sys.exit(0)

tests/spoof/tesseract_big_image_error.py

@@ -44,7 +44,7 @@ def main():
     elif sys.argv[1] == '--list-langs':
         print('List of available languages (1):\neng\n', file=sys.stderr)
         sys.exit(0)
-    elif sys.argv[1] == '--print-parameters':
+    elif sys.argv[-2] == '--print-parameters':
         print('A parameter list would go here\ntextonly_pdf 0\n', file=sys.stderr)
         sys.exit(0)
     elif sys.argv[-2] == 'hocr':

tests/spoof/tesseract_cache.py

@@ -100,6 +100,8 @@ def main():
     # Convert non-standard but supported -psm to --psm
     sys.argv = ['--psm' if arg == '-psm' else arg for arg in sys.argv]
 
+    if '_OCRMYPDF_TEST_INFILE' not in os.environ:
+        real_tesseract()  # test not properly set up
     source = os.environ['_OCRMYPDF_TEST_INFILE']  # required
     args = parser.parse_args()
 

tests/spoof/tesseract_crash.py

@@ -50,7 +50,7 @@ def main():
     elif sys.argv[1] == '--list-langs':
         print('List of available languages (1):\neng', file=sys.stderr)
         sys.exit(0)
-    elif sys.argv[1] == '--print-parameters':
+    elif sys.argv[-2] == '--print-parameters':
         print('A parameter list would go here\ntextonly_pdf 0\n', file=sys.stderr)
         sys.exit(0)
     elif sys.argv[-2] == 'hocr':

tests/spoof/tesseract_noop.py

@@ -76,7 +76,7 @@ def main():
     elif sys.argv[1] == '--list-langs':
         print('List of available languages (1):\neng', file=sys.stderr)
         sys.exit(0)
-    elif sys.argv[1] == '--print-parameters':
+    elif sys.argv[-2] == '--print-parameters':
         print("Some parameters", file=sys.stderr)
         print("textonly_pdf\t1\tSome help text")
         sys.exit(0)

tests/test_lept.py

@@ -38,7 +38,8 @@ def test_colormap_backgroundnorm(resources):
 def crom_pix(resources):
     pix = lept.Pix.open(resources / 'crom.png')
     im = Image.open(resources / 'crom.png')
-    return pix, im
+    yield pix, im
+    im.close()
 
 
 def test_pix_basic(crom_pix):

tests/test_main.py

@@ -118,8 +118,8 @@ def test_deskew(spoof_tesseract_noop, resources, outdir):
 
 def test_remove_background(spoof_tesseract_noop, resources, outdir):
     # Ensure the input image does not contain pure white/black
-    im = Image.open(resources / 'congress.jpg')
-    assert im.getextrema() != ((0, 255), (0, 255), (0, 255))
+    with Image.open(resources / 'congress.jpg') as im:
+        assert im.getextrema() != ((0, 255), (0, 255), (0, 255))
 
     output_pdf = check_ocrmypdf(
         resources / 'congress.jpg',
@@ -145,8 +145,8 @@ def test_remove_background(spoof_tesseract_noop, resources, outdir):
     )
 
     # The output image should contain pure white and black
-    im = Image.open(output_png)
-    assert im.getextrema() == ((0, 255), (0, 255), (0, 255))
+    with Image.open(output_png) as im:
+        assert im.getextrema() == ((0, 255), (0, 255), (0, 255))
 
 
 # This will run 5 * 2 * 2 = 20 test cases
@@ -349,10 +349,9 @@ def test_german(spoof_tesseract_cache, resources, outdir):
         sidecar,
         env=spoof_tesseract_cache,
     )
-    print(os.environ)
-    assert (
-        p.returncode == ExitCode.ok
-    ), "This test may fail if Tesseract language packs are missing"
+    if 'deu' not in tesseract.languages():
+        pytest.xfail(reason="tesseract-deu language pack not installed")
+    assert p.returncode == ExitCode.ok, "Requires tesseract deu language pack"
 
 
 def test_klingon(resources, outpdf):
@@ -652,26 +651,11 @@ THIS FILE IS INVALID
     assert p.returncode == ExitCode.invalid_config
 
 
-@pytest.mark.skipif(tesseract.v4(), reason='arg has no effect in 4.0-beta1')
-def test_user_words(resources, outdir):
+@pytest.mark.skipif(not tesseract.has_user_words(), reason='not functional until 4.1.0')
+def test_user_words_ocr(resources, outdir):
+    # Does not actually test if --user-words causes output to differ
     word_list = outdir / 'wordlist.txt'
-    sidecar_before = outdir / 'sidecar_before.txt'
-    sidecar_after = outdir / 'sidecar_after.txt'
-
-    # Don't know how to make this test pass on various versions and platforms
-    # so weaken to merely testing that the argument is accepted
-    consistent = False
-
-    if consistent:
-        check_ocrmypdf(
-            resources / 'crom.png',
-            outdir / 'out.pdf',
-            '--image-dpi',
-            150,
-            '--sidecar',
-            sidecar_before,
-        )
-        assert 'cromulent' not in sidecar_before.open().read()
+    sidecar_after = outdir / 'sidecar.txt'
 
     with word_list.open('w') as f:
         f.write('cromulent\n')  # a perfectly cromulent word
@@ -687,9 +671,6 @@ def test_user_words(resources, outdir):
         word_list,
     )
 
-    if consistent:
-        assert 'cromulent' in sidecar_after.open().read()
-
 
 def test_form_xobject(spoof_tesseract_noop, resources, outpdf):
     check_ocrmypdf(
@@ -810,6 +791,7 @@ def test_compression_preserved(
         assert pdfimage.color == Colorspace.rgb, "Colorspace changed"
     elif im.mode.startswith('L'):
         assert pdfimage.color == Colorspace.gray, "Colorspace changed"
+    im.close()
 
 
 @pytest.mark.parametrize(
@@ -871,6 +853,7 @@ def test_compression_changed(
         assert pdfimage.color == Colorspace.rgb, "Colorspace changed"
     elif im.mode.startswith('L'):
         assert pdfimage.color == Colorspace.gray, "Colorspace changed"
+    im.close()
 
 
 def test_sidecar_pagecount(spoof_tesseract_cache, resources, outpdf):

tests/test_optimize.py

@@ -48,11 +48,11 @@ def test_mono_not_inverted(resources, outdir):
         xres=10,
         yres=10,
         raster_device='pnggray',
-        log=logging.getLogger(name='test_mono_flip'),
+        log=logging.getLogger(name='test_mono_not_inverted'),
     )
 
-    im = Image.open(fspath(outdir / 'im.png'))
-    assert im.getpixel((0, 0)) == 255, "Expected white background"
+    with Image.open(fspath(outdir / 'im.png')) as im:
+        assert im.getpixel((0, 0)) == 255, "Expected white background"
 
 
 @pytest.mark.skipif(not pngquant.available(), reason='need pngquant')
@@ -110,10 +110,10 @@ def test_flate_to_jbig2(resources, outdir, spoof_tesseract_noop):
     # This test requires an image that pngquant is capable of converting to
     # to 1bpp - so use an existing 1bpp image, convert up, confirm it can
     # convert down
-    im = Image.open(fspath(resources / 'typewriter.png'))
-    assert im.mode in ('1', 'P')
-    im = im.convert('L')
-    im.save(fspath(outdir / 'type8.png'))
+    with Image.open(fspath(resources / 'typewriter.png')) as im:
+        assert im.mode in ('1', 'P')
+        im = im.convert('L')
+        im.save(fspath(outdir / 'type8.png'))
 
     check_ocrmypdf(
         outdir / 'type8.png',

tests/test_rotation.py

@@ -224,12 +224,12 @@ def test_rotate_deskew_timeout(resources, outdir):
 @pytest.mark.parametrize('image_angle', (0, 90, 180, 270))
 def test_rotate_page_level(image_angle, page_angle, resources, outdir):
     def make_rotate_test(prefix, image_angle, page_angle):
-        im = Image.open(fspath(resources / 'typewriter.png'))
-        if image_angle != 0:
-            ccw_angle = -image_angle % 360
-            im = im.transpose(getattr(Image, f'ROTATE_{ccw_angle}'))
         memimg = BytesIO()
-        im.save(memimg, format='PNG')
+        with Image.open(fspath(resources / 'typewriter.png')) as im:
+            if image_angle != 0:
+                ccw_angle = -image_angle % 360
+                im = im.transpose(getattr(Image, f'ROTATE_{ccw_angle}'))
+            im.save(memimg, format='PNG')
         memimg.seek(0)
         mempdf = BytesIO()
         img2pdf.convert(

tests/test_validation.py

@@ -37,15 +37,21 @@ def test_hocr_notlatin_warning(caplog):
 
 
 def test_old_ghostscript(caplog):
-    with patch('ocrmypdf.exec.ghostscript.version', return_value='9.19'):
+    with patch('ocrmypdf.exec.ghostscript.version', return_value='9.19'), patch(
+        'ocrmypdf.exec.tesseract.has_textonly_pdf', return_value=True
+    ):
         vd.check_options_output(make_opts(language='chi_sim', output_type='pdfa'))
         assert 'Ghostscript does not work correctly' in caplog.text
 
-    with patch('ocrmypdf.exec.ghostscript.version', return_value='9.18'):
+    with patch('ocrmypdf.exec.ghostscript.version', return_value='9.18'), patch(
+        'ocrmypdf.exec.tesseract.has_textonly_pdf', return_value=True
+    ):
         with pytest.raises(MissingDependencyError):
             vd.check_options_output(make_opts(output_type='pdfa-3'))
 
-    with patch('ocrmypdf.exec.ghostscript.version', return_value='9.24'):
+    with patch('ocrmypdf.exec.ghostscript.version', return_value='9.24'), patch(
+        'ocrmypdf.exec.tesseract.has_textonly_pdf', return_value=True
+    ):
         with pytest.raises(MissingDependencyError):
             vd.check_dependency_versions(make_opts())