OCRmyPDF/tests/test_main.py

# © 2015-19 James R. Barlow: github.com/jbarlow83
#
# This file is part of OCRmyPDF.
#
# OCRmyPDF is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# OCRmyPDF is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.

import logging
import os
import shutil
from math import isclose
from pathlib import Path
from subprocess import PIPE, run

import PIL
import pytest
from PIL import Image

import ocrmypdf
import pikepdf
from ocrmypdf.exceptions import ExitCode, MissingDependencyError
from ocrmypdf.exec import ghostscript, qpdf, tesseract
from ocrmypdf.leptonica import Pix
from ocrmypdf.pdfa import file_claims_pdfa
from ocrmypdf.pdfinfo import Colorspace, Encoding, PdfInfo

# pytest.helpers is dynamic
# pylint: disable=no-member,redefined-outer-name

check_ocrmypdf = pytest.helpers.check_ocrmypdf
run_ocrmypdf = pytest.helpers.run_ocrmypdf
spoof = pytest.helpers.spoof


RENDERERS = ['hocr', 'sandwich']


@pytest.fixture(scope='session')
def spoof_tesseract_crash(tmp_path_factory):
    return spoof(tmp_path_factory, tesseract='tesseract_crash.py')


@pytest.fixture(scope='session')
def spoof_tesseract_big_image_error(tmp_path_factory):
    return spoof(tmp_path_factory, tesseract='tesseract_big_image_error.py')


@pytest.fixture(scope='session')
def spoof_no_tess_no_pdfa(tmp_path_factory):
    return spoof(
        tmp_path_factory, tesseract='tesseract_noop.py', gs='gs_pdfa_failure.py'
    )


@pytest.fixture(scope='session')
def spoof_no_tess_pdfa_warning(tmp_path_factory):
    return spoof(
        tmp_path_factory, tesseract='tesseract_noop.py', gs='gs_feature_elision.py'
    )


@pytest.fixture(scope='session')
def spoof_no_tess_gs_render_fail(tmp_path_factory):
    return spoof(
        tmp_path_factory, tesseract='tesseract_noop.py', gs='gs_render_failure.py'
    )


@pytest.fixture(scope='session')
def spoof_no_tess_gs_raster_fail(tmp_path_factory):
    return spoof(
        tmp_path_factory, tesseract='tesseract_noop.py', gs='gs_raster_failure.py'
    )


def test_quick(spoof_tesseract_cache, resources, outpdf):
    check_ocrmypdf(resources / 'ccitt.pdf', outpdf, env=spoof_tesseract_cache)


def test_deskew(spoof_tesseract_noop, resources, outdir):
    # Run with deskew
    deskewed_pdf = check_ocrmypdf(
        resources / 'skew.pdf', outdir / 'skew.pdf', '-d', env=spoof_tesseract_noop
    )

    # Now render as an image again and use Leptonica to find the skew angle
    # to confirm that it was deskewed
    log = logging.getLogger()

    deskewed_png = outdir / 'deskewed.png'

    ghostscript.rasterize_pdf(
        deskewed_pdf,
        deskewed_png,
        xres=150,
        yres=150,
        raster_device='pngmono',
        log=log,
        pageno=1,
    )

    pix = Pix.open(deskewed_png)
    skew_angle, _skew_confidence = pix.find_skew()

    print(skew_angle)
    assert -0.5 < skew_angle < 0.5, "Deskewing failed"


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))

    output_pdf = check_ocrmypdf(
        resources / 'congress.jpg',
        outdir / 'test_remove_bg.pdf',
        '--remove-background',
        '--image-dpi',
        '150',
        env=spoof_tesseract_noop,
    )

    log = logging.getLogger()

    output_png = outdir / 'remove_bg.png'

    ghostscript.rasterize_pdf(
        output_pdf,
        output_png,
        xres=100,
        yres=100,
        raster_device='png16m',
        log=log,
        pageno=1,
    )

    # The output image should contain pure white and black
    im = Image.open(output_png)
    assert im.getextrema() == ((0, 255), (0, 255), (0, 255))


# This will run 5 * 2 * 2 = 20 test cases
@pytest.mark.parametrize(
    "pdf", ['palette.pdf', 'cmyk.pdf', 'ccitt.pdf', 'jbig2.pdf', 'lichtenstein.pdf']
)
@pytest.mark.parametrize("renderer", ['sandwich', 'hocr'])
@pytest.mark.parametrize("output_type", ['pdf', 'pdfa'])
def test_exotic_image(
    spoof_tesseract_cache, pdf, renderer, output_type, resources, outdir
):
    outfile = outdir / f'test_{pdf}_{renderer}.pdf'
    check_ocrmypdf(
        resources / pdf,
        outfile,
        '-dc' if pytest.helpers.have_unpaper() else '-d',
        '-v',
        '1',
        '--output-type',
        output_type,
        '--sidecar',
        '--skip-text',
        '--pdf-renderer',
        renderer,
        env=spoof_tesseract_cache,
    )

    assert outfile.with_suffix('.pdf.txt').exists()


@pytest.mark.parametrize('renderer', RENDERERS)
def test_oversample(spoof_tesseract_cache, renderer, resources, outpdf):
    oversampled_pdf = check_ocrmypdf(
        resources / 'skew.pdf',
        outpdf,
        '--oversample',
        '350',
        '-f',
        '--pdf-renderer',
        renderer,
        env=spoof_tesseract_cache,
    )

    pdfinfo = PdfInfo(oversampled_pdf)

    print(pdfinfo[0].xres)
    assert abs(pdfinfo[0].xres - 350) < 1


def test_repeat_ocr(resources, no_outpdf):
    p, _, _ = run_ocrmypdf(resources / 'graph_ocred.pdf', no_outpdf)
    assert p.returncode != 0


def test_force_ocr(spoof_tesseract_cache, resources, outpdf):
    out = check_ocrmypdf(
        resources / 'graph_ocred.pdf', outpdf, '-f', env=spoof_tesseract_cache
    )
    pdfinfo = PdfInfo(out)
    assert pdfinfo[0].has_text


def test_skip_ocr(spoof_tesseract_cache, resources, outpdf):
    out = check_ocrmypdf(
        resources / 'graph_ocred.pdf', outpdf, '-s', env=spoof_tesseract_cache
    )
    pdfinfo = PdfInfo(out)
    assert pdfinfo[0].has_text


def test_redo_ocr(spoof_tesseract_cache, resources, outpdf):
    in_ = resources / 'graph_ocred.pdf'
    before = PdfInfo(in_, detailed_page_analysis=True)
    out = outpdf
    out = check_ocrmypdf(in_, out, '--redo-ocr')
    after = PdfInfo(out, detailed_page_analysis=True)
    assert before[0].has_text and after[0].has_text
    assert (
        before[0].get_textareas() != after[0].get_textareas()
    ), "Expected text to be different after re-OCR"


def test_argsfile(spoof_tesseract_noop, resources, outdir):
    path_argsfile = outdir / 'test_argsfile.txt'
    with open(str(path_argsfile), 'w') as argsfile:
        print(
            '--title',
            'ArgsFile Test',
            '--author',
            'Test Cases',
            sep='\n',
            end='\n',
            file=argsfile,
        )
    check_ocrmypdf(
        resources / 'graph.pdf',
        path_argsfile,
        '@' + str(outdir / 'test_argsfile.txt'),
        env=spoof_tesseract_noop,
    )


@pytest.mark.parametrize('renderer', RENDERERS)
def test_ocr_timeout(renderer, resources, outpdf):
    out = check_ocrmypdf(
        resources / 'skew.pdf',
        outpdf,
        '--tesseract-timeout',
        '0',
        '--pdf-renderer',
        renderer,
    )
    pdfinfo = PdfInfo(out)
    assert not pdfinfo[0].has_text


def test_skip_big(spoof_tesseract_cache, resources, outpdf):
    out = check_ocrmypdf(
        resources / 'jbig2.pdf', outpdf, '--skip-big', '1', env=spoof_tesseract_cache
    )
    pdfinfo = PdfInfo(out)
    assert not pdfinfo[0].has_text


@pytest.mark.parametrize('renderer', RENDERERS)
@pytest.mark.parametrize('output_type', ['pdf', 'pdfa'])
def test_maximum_options(
    spoof_tesseract_cache, renderer, output_type, resources, outpdf
):
    check_ocrmypdf(
        resources / 'multipage.pdf',
        outpdf,
        '-d',
        '-ci' if pytest.helpers.have_unpaper() else None,
        '-f',
        '-k',
        '--oversample',
        '300',
        '--remove-background',
        '--skip-big',
        '10',
        '--title',
        'Too Many Weird Files',
        '--author',
        'py.test',
        '--pdf-renderer',
        renderer,
        '--output-type',
        output_type,
        env=spoof_tesseract_cache,
    )


def test_tesseract_missing_tessdata(resources, no_outpdf):
    env = os.environ.copy()
    env['TESSDATA_PREFIX'] = '/tmp'

    p, _, err = run_ocrmypdf(
        resources / 'graph_ocred.pdf', no_outpdf, '-v', '1', '--skip-text', env=env
    )
    assert p.returncode == ExitCode.missing_dependency, err


def test_invalid_input_pdf(resources, no_outpdf):
    p, out, err = run_ocrmypdf(resources / 'invalid.pdf', no_outpdf)
    assert p.returncode == ExitCode.input_file, err


def test_blank_input_pdf(resources, outpdf):
    p, out, err = run_ocrmypdf(resources / 'blank.pdf', outpdf)
    assert p.returncode == ExitCode.ok


def test_force_ocr_on_pdf_with_no_images(spoof_tesseract_crash, resources, no_outpdf):
    # As a correctness test, make sure that --force-ocr on a PDF with no
    # content still triggers tesseract. If tesseract crashes, then it was
    # called.
    p, _, err = run_ocrmypdf(
        resources / 'blank.pdf', no_outpdf, '--force-ocr', env=spoof_tesseract_crash
    )
    assert p.returncode == ExitCode.child_process_error, err
    assert not os.path.exists(no_outpdf)


@pytest.mark.skipif(
    pytest.helpers.is_macos() and pytest.helpers.running_in_travis(),
    reason="takes too long to install language packs in Travis macOS homebrew",
)
def test_german(spoof_tesseract_cache, resources, outdir):
    # Produce a sidecar too - implicit test that system locale is set up
    # properly. It is fine that we are testing -l deu on a French file because
    # we are exercising the functionality not going for accuracy.
    sidecar = outdir / 'francais.txt'
    p, out, err = run_ocrmypdf(
        resources / 'francais.pdf',
        outdir / 'francais.pdf',
        '-l',
        'deu',  # more commonly installed
        '--sidecar',
        sidecar,
        env=spoof_tesseract_cache,
    )
    print(os.environ)
    assert (
        p.returncode == ExitCode.ok
    ), "This test may fail if Tesseract language packs are missing"


def test_klingon(resources, outpdf):
    p, out, err = run_ocrmypdf(resources / 'francais.pdf', outpdf, '-l', 'klz')
    assert p.returncode == ExitCode.missing_dependency


def test_missing_docinfo(spoof_tesseract_noop, resources, outpdf):
    p, out, err = run_ocrmypdf(
        resources / 'missing_docinfo.pdf',
        outpdf,
        '-l',
        'eng',
        '--skip-text',
        env=spoof_tesseract_noop,
    )
    assert p.returncode == ExitCode.ok, err


def test_uppercase_extension(spoof_tesseract_noop, resources, outdir):
    shutil.copy(str(resources / "skew.pdf"), str(outdir / "UPPERCASE.PDF"))

    check_ocrmypdf(
        outdir / "UPPERCASE.PDF", outdir / "UPPERCASE_OUT.PDF", env=spoof_tesseract_noop
    )


def test_input_file_not_found(no_outpdf):
    input_file = "does not exist.pdf"
    p, out, err = run_ocrmypdf(input_file, no_outpdf)
    assert p.returncode == ExitCode.input_file
    assert input_file in out or input_file in err


def test_input_file_not_a_pdf(no_outpdf):
    input_file = __file__  # Try to OCR this file
    p, out, err = run_ocrmypdf(input_file, no_outpdf)
    assert p.returncode == ExitCode.input_file
    assert input_file in out or input_file in err


def test_encrypted(resources, no_outpdf):
    p, out, err = run_ocrmypdf(resources / 'skew-encrypted.pdf', no_outpdf)
    assert p.returncode == ExitCode.encrypted_pdf
    assert out.find('encrypted')


@pytest.mark.parametrize('renderer', RENDERERS)
def test_pagesegmode(renderer, spoof_tesseract_cache, resources, outpdf):
    check_ocrmypdf(
        resources / 'skew.pdf',
        outpdf,
        '--tesseract-pagesegmode',
        '7',
        '-v',
        '1',
        '--pdf-renderer',
        renderer,
        env=spoof_tesseract_cache,
    )


@pytest.mark.parametrize('renderer', RENDERERS)
def test_tesseract_crash(renderer, spoof_tesseract_crash, resources, no_outpdf):
    p, out, err = run_ocrmypdf(
        resources / 'ccitt.pdf',
        no_outpdf,
        '-v',
        '1',
        '--pdf-renderer',
        renderer,
        env=spoof_tesseract_crash,
    )
    assert p.returncode == ExitCode.child_process_error
    assert not os.path.exists(no_outpdf)
    assert "ERROR" in err


def test_tesseract_crash_autorotate(spoof_tesseract_crash, resources, no_outpdf):
    p, out, err = run_ocrmypdf(
        resources / 'ccitt.pdf', no_outpdf, '-r', env=spoof_tesseract_crash
    )
    assert p.returncode == ExitCode.child_process_error
    assert not os.path.exists(no_outpdf)
    assert "ERROR" in err
    print(out)
    print(err)


@pytest.mark.parametrize('renderer', RENDERERS)
@pytest.mark.slow
def test_tesseract_image_too_big(
    renderer, spoof_tesseract_big_image_error, resources, outpdf
):
    check_ocrmypdf(
        resources / 'hugemono.pdf',
        outpdf,
        '-r',
        '--pdf-renderer',
        renderer,
        '--max-image-mpixels',
        '0',
        env=spoof_tesseract_big_image_error,
    )


def test_algo4(resources, spoof_tesseract_noop, outpdf):
    p, _, _ = run_ocrmypdf(
        resources / 'encrypted_algo4.pdf', outpdf, env=spoof_tesseract_noop
    )
    assert p.returncode == ExitCode.encrypted_pdf


@pytest.mark.parametrize('renderer', RENDERERS)
def test_non_square_resolution(renderer, spoof_tesseract_cache, resources, outpdf):
    # Confirm input image is non-square resolution
    in_pageinfo = PdfInfo(resources / 'aspect.pdf')
    assert in_pageinfo[0].xres != in_pageinfo[0].yres

    check_ocrmypdf(
        resources / 'aspect.pdf',
        outpdf,
        '--pdf-renderer',
        renderer,
        env=spoof_tesseract_cache,
    )

    out_pageinfo = PdfInfo(outpdf)

    # Confirm resolution was kept the same
    assert in_pageinfo[0].xres == out_pageinfo[0].xres
    assert in_pageinfo[0].yres == out_pageinfo[0].yres


@pytest.mark.parametrize('renderer', RENDERERS)
def test_convert_to_square_resolution(
    renderer, spoof_tesseract_cache, resources, outpdf
):
    # Confirm input image is non-square resolution
    in_pageinfo = PdfInfo(resources / 'aspect.pdf')
    assert in_pageinfo[0].xres != in_pageinfo[0].yres

    # --force-ocr requires means forced conversion to square resolution
    check_ocrmypdf(
        resources / 'aspect.pdf',
        outpdf,
        '--force-ocr',
        '--pdf-renderer',
        renderer,
        env=spoof_tesseract_cache,
    )

    out_pageinfo = PdfInfo(outpdf)

    in_p0, out_p0 = in_pageinfo[0], out_pageinfo[0]

    # Resolution show now be equal
    assert out_p0.xres == out_p0.yres

    # Page size should match input page size
    assert isclose(in_p0.width_inches, out_p0.width_inches)
    assert isclose(in_p0.height_inches, out_p0.height_inches)

    # Because we rasterized the page to produce a new image, it should occupy
    # the entire page
    out_im_w = out_p0.images[0].width / out_p0.images[0].xres
    out_im_h = out_p0.images[0].height / out_p0.images[0].yres
    assert isclose(out_p0.width_inches, out_im_w)
    assert isclose(out_p0.height_inches, out_im_h)


def test_image_to_pdf(spoof_tesseract_noop, resources, outpdf):
    check_ocrmypdf(
        resources / 'crom.png', outpdf, '--image-dpi', '200', env=spoof_tesseract_noop
    )


def test_jbig2_passthrough(spoof_tesseract_cache, resources, outpdf):
    out = check_ocrmypdf(
        resources / 'jbig2.pdf',
        outpdf,
        '--output-type',
        'pdf',
        '--pdf-renderer',
        'hocr',
        env=spoof_tesseract_cache,
    )
    out_pageinfo = PdfInfo(out)
    assert out_pageinfo[0].images[0].enc == Encoding.jbig2


def test_masks(spoof_tesseract_noop, resources, outpdf):
    assert (
        ocrmypdf.ocr(
            resources / 'masks.pdf', outpdf, tesseract_env=spoof_tesseract_noop
        )
        == ExitCode.ok
    )


def test_linearized_pdf_and_indirect_object(spoof_tesseract_noop, resources, outpdf):
    check_ocrmypdf(resources / 'epson.pdf', outpdf, env=spoof_tesseract_noop)


def test_ghostscript_pdfa_failure(spoof_no_tess_no_pdfa, resources, outpdf):
    p, out, err = run_ocrmypdf(
        resources / 'ccitt.pdf', outpdf, env=spoof_no_tess_no_pdfa
    )
    assert (
        p.returncode == ExitCode.pdfa_conversion_failed
    ), "Unexpected return when PDF/A fails"


def test_ghostscript_feature_elision(spoof_no_tess_pdfa_warning, resources, outpdf):
    check_ocrmypdf(resources / 'ccitt.pdf', outpdf, env=spoof_no_tess_pdfa_warning)


def test_very_high_dpi(spoof_tesseract_cache, resources, outpdf):
    "Checks for a Decimal quantize error with high DPI, etc"
    check_ocrmypdf(resources / '2400dpi.pdf', outpdf, env=spoof_tesseract_cache)
    pdfinfo = PdfInfo(outpdf)

    image = pdfinfo[0].images[0]
    assert isclose(image.xres, image.yres)
    assert isclose(image.xres, 2400)


def test_overlay(spoof_tesseract_noop, resources, outpdf):
    check_ocrmypdf(
        resources / 'overlay.pdf', outpdf, '--skip-text', env=spoof_tesseract_noop
    )


def test_destination_not_writable(spoof_tesseract_noop, resources, outdir):
    if os.getuid() == 0 or os.geteuid() == 0:
        pytest.xfail(reason="root can write to anything")
    protected_file = outdir / 'protected.pdf'
    protected_file.touch()
    protected_file.chmod(0o400)  # Read-only
    p, out, err = run_ocrmypdf(
        resources / 'jbig2.pdf', protected_file, env=spoof_tesseract_noop
    )
    assert p.returncode == ExitCode.file_access_error, "Expected error"


def test_tesseract_config_valid(resources, outdir):
    cfg_file = outdir / 'test.cfg'
    with cfg_file.open('w') as f:
        f.write(
            '''\
load_system_dawg 0
language_model_penalty_non_dict_word 0
language_model_penalty_non_freq_dict_word 0
'''
        )

    check_ocrmypdf(
        resources / 'ccitt.pdf', outdir / 'out.pdf', '--tesseract-config', cfg_file
    )


@pytest.mark.parametrize('renderer', RENDERERS)
def test_tesseract_config_notfound(renderer, resources, outdir):
    cfg_file = outdir / 'nofile.cfg'

    p, out, err = run_ocrmypdf(
        resources / 'ccitt.pdf',
        outdir / 'out.pdf',
        '--pdf-renderer',
        renderer,
        '--tesseract-config',
        cfg_file,
    )
    assert "Can't open" in err, "No error message about missing config file"
    assert p.returncode == ExitCode.ok, err


@pytest.mark.parametrize('renderer', RENDERERS)
def test_tesseract_config_invalid(renderer, resources, outdir):
    cfg_file = outdir / 'test.cfg'
    with cfg_file.open('w') as f:
        f.write(
            '''\
THIS FILE IS INVALID
'''
        )

    p, out, err = run_ocrmypdf(
        resources / 'ccitt.pdf',
        outdir / 'out.pdf',
        '--pdf-renderer',
        renderer,
        '--tesseract-config',
        cfg_file,
    )
    assert "parameter not found" in err.lower(), "No error message"
    assert p.returncode == ExitCode.invalid_config


@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_after = outdir / 'sidecar.txt'

    with word_list.open('w') as f:
        f.write('cromulent\n')  # a perfectly cromulent word

    check_ocrmypdf(
        resources / 'crom.png',
        outdir / 'out.pdf',
        '--image-dpi',
        150,
        '--sidecar',
        sidecar_after,
        '--user-words',
        word_list,
    )


def test_form_xobject(spoof_tesseract_noop, resources, outpdf):
    check_ocrmypdf(
        resources / 'formxobject.pdf', outpdf, '--force-ocr', env=spoof_tesseract_noop
    )


@pytest.mark.parametrize('renderer', RENDERERS)
def test_pagesize_consistency(renderer, resources, outpdf):

    first_page_dimensions = pytest.helpers.first_page_dimensions

    infile = resources / 'linn.pdf'

    before_dims = first_page_dimensions(infile)

    check_ocrmypdf(
        infile,
        outpdf,
        '--pdf-renderer',
        renderer,
        '--clean' if pytest.helpers.have_unpaper() else None,
        '--deskew',
        '--remove-background',
        '--clean-final' if pytest.helpers.have_unpaper() else None,
    )

    after_dims = first_page_dimensions(outpdf)

    assert isclose(before_dims[0], after_dims[0])
    assert isclose(before_dims[1], after_dims[1])


def test_skip_big_with_no_images(spoof_tesseract_noop, resources, outpdf):
    check_ocrmypdf(
        resources / 'blank.pdf',
        outpdf,
        '--skip-big',
        '5',
        '--force-ocr',
        env=spoof_tesseract_noop,
    )


def test_gs_render_failure(spoof_no_tess_gs_render_fail, resources, outpdf):
    p, out, err = run_ocrmypdf(
        resources / 'blank.pdf', outpdf, env=spoof_no_tess_gs_render_fail
    )
    print(err)
    assert p.returncode == ExitCode.child_process_error


def test_gs_raster_failure(spoof_no_tess_gs_raster_fail, resources, outpdf):
    p, out, err = run_ocrmypdf(
        resources / 'ccitt.pdf', outpdf, env=spoof_no_tess_gs_raster_fail
    )
    print(err)
    assert p.returncode == ExitCode.child_process_error


@pytest.mark.skipif(
    '8.0.0' <= qpdf.version() <= '8.0.1',
    reason="qpdf regression on pages with no contents",
)
def test_no_contents(spoof_tesseract_noop, resources, outpdf):
    check_ocrmypdf(
        resources / 'no_contents.pdf', outpdf, '--force-ocr', env=spoof_tesseract_noop
    )


@pytest.mark.parametrize(
    'image', ['baiona.png', 'baiona_gray.png', 'baiona_alpha.png', 'congress.jpg']
)
def test_compression_preserved(
    spoof_tesseract_noop, ocrmypdf_exec, resources, image, outpdf
):
    input_file = str(resources / image)
    output_file = str(outpdf)

    im = Image.open(input_file)
    # Runs: ocrmypdf - output.pdf < testfile
    with open(input_file, 'rb') as input_stream:
        p_args = ocrmypdf_exec + [
            '--optimize',
            '0',
            '--image-dpi',
            '150',
            '--output-type',
            'pdf',
            '-',
            output_file,
        ]
        p = run(
            p_args,
            stdout=PIPE,
            stderr=PIPE,
            stdin=input_stream,
            universal_newlines=True,
            env=spoof_tesseract_noop,
        )

        if im.mode in ('RGBA', 'LA'):
            # If alpha image is input, expect an error
            assert p.returncode != ExitCode.ok and 'alpha' in p.stderr
            return

        assert p.returncode == ExitCode.ok, p.stderr

    pdfinfo = PdfInfo(output_file)

    pdfimage = pdfinfo[0].images[0]

    if input_file.endswith('.png'):
        assert pdfimage.enc != Encoding.jpeg, "Lossless compression changed to lossy!"
    elif input_file.endswith('.jpg'):
        assert pdfimage.enc == Encoding.jpeg, "Lossy compression changed to lossless!"
    if im.mode.startswith('RGB') or im.mode.startswith('BGR'):
        assert pdfimage.color == Colorspace.rgb, "Colorspace changed"
    elif im.mode.startswith('L'):
        assert pdfimage.color == Colorspace.gray, "Colorspace changed"


@pytest.mark.parametrize(
    'image,compression',
    [
        ('baiona.png', 'jpeg'),
        ('baiona_gray.png', 'lossless'),
        ('congress.jpg', 'lossless'),
    ],
)
def test_compression_changed(
    spoof_tesseract_noop, ocrmypdf_exec, resources, image, compression, outpdf
):
    input_file = str(resources / image)
    output_file = str(outpdf)

    im = Image.open(input_file)

    # Runs: ocrmypdf - output.pdf < testfile
    with open(input_file, 'rb') as input_stream:
        p_args = ocrmypdf_exec + [
            '--image-dpi',
            '150',
            '--output-type',
            'pdfa',
            '--optimize',
            '0',
            '--pdfa-image-compression',
            compression,
            '-',
            output_file,
        ]
        p = run(
            p_args,
            stdout=PIPE,
            stderr=PIPE,
            stdin=input_stream,
            universal_newlines=True,
            env=spoof_tesseract_noop,
        )
        assert p.returncode == ExitCode.ok, p.stderr

    pdfinfo = PdfInfo(output_file)

    pdfimage = pdfinfo[0].images[0]

    if compression == "jpeg":
        assert pdfimage.enc == Encoding.jpeg
    else:
        if ghostscript.jpeg_passthrough_available():
            # Ghostscript 9.23 adds JPEG passthrough, which allows a JPEG to be
            # copied without transcoding - so report
            if image.endswith('jpg'):
                assert pdfimage.enc == Encoding.jpeg
        else:
            assert pdfimage.enc not in (Encoding.jpeg, Encoding.jpeg2000)

    if im.mode.startswith('RGB') or im.mode.startswith('BGR'):
        assert pdfimage.color == Colorspace.rgb, "Colorspace changed"
    elif im.mode.startswith('L'):
        assert pdfimage.color == Colorspace.gray, "Colorspace changed"


def test_sidecar_pagecount(spoof_tesseract_cache, resources, outpdf):
    sidecar = outpdf.with_suffix('.txt')
    check_ocrmypdf(
        resources / 'multipage.pdf',
        outpdf,
        '--skip-text',
        '--sidecar',
        sidecar,
        env=spoof_tesseract_cache,
    )

    pdfinfo = PdfInfo(resources / 'multipage.pdf')
    num_pages = len(pdfinfo)

    with open(sidecar, 'r') as f:
        ocr_text = f.read()

    # There should a formfeed between each pair of pages, so the count of
    # formfeeds is the page count less one
    assert (
        ocr_text.count('\f') == num_pages - 1
    ), "Sidecar page count does not match PDF page count"


def test_sidecar_nonempty(spoof_tesseract_cache, resources, outpdf):
    sidecar = outpdf.with_suffix('.txt')
    check_ocrmypdf(
        resources / 'ccitt.pdf', outpdf, '--sidecar', sidecar, env=spoof_tesseract_cache
    )

    with open(sidecar, 'r') as f:
        ocr_text = f.read()
    assert 'the' in ocr_text


@pytest.mark.parametrize('pdfa_level', ['1', '2', '3'])
def test_pdfa_n(spoof_tesseract_cache, pdfa_level, resources, outpdf):
    if pdfa_level == '3' and ghostscript.version() < '9.19':
        pytest.xfail(reason='Ghostscript >= 9.19 required')

    check_ocrmypdf(
        resources / 'ccitt.pdf',
        outpdf,
        '--output-type',
        'pdfa-' + pdfa_level,
        env=spoof_tesseract_cache,
    )

    pdfa_info = file_claims_pdfa(outpdf)
    assert pdfa_info['conformance'] == f'PDF/A-{pdfa_level}B'


@pytest.mark.skipif(
    PIL.__version__ < '5.0.0', reason="Pillow < 5.0.0 doesn't raise the exception"
)
@pytest.mark.slow
def test_decompression_bomb(resources, outpdf):
    p, out, err = run_ocrmypdf(resources / 'hugemono.pdf', outpdf)
    assert 'decompression bomb' in err

    p, out, err = run_ocrmypdf(
        resources / 'hugemono.pdf', outpdf, '--max-image-mpixels', '2000'
    )
    assert p.returncode == 0


def test_text_curves(spoof_tesseract_noop, resources, outpdf):
    check_ocrmypdf(resources / 'vector.pdf', outpdf, env=spoof_tesseract_noop)

    info = PdfInfo(outpdf)
    assert len(info.pages[0].images) == 0, "added images to the vector PDF"

    check_ocrmypdf(
        resources / 'vector.pdf', outpdf, '--force-ocr', env=spoof_tesseract_noop
    )

    info = PdfInfo(outpdf)
    assert len(info.pages[0].images) != 0, "force did not rasterize"


def test_output_is_dir(spoof_tesseract_noop, resources, outdir):
    p, out, err = run_ocrmypdf(
        resources / 'trivial.pdf', outdir, '--force-ocr', env=spoof_tesseract_noop
    )
    assert p.returncode == ExitCode.file_access_error
    assert 'is not a writable file' in err


def test_output_is_symlink(spoof_tesseract_noop, resources, outdir):
    sym = Path(outdir / 'this_is_a_symlink')
    sym.symlink_to(outdir / 'out.pdf')
    p, out, err = run_ocrmypdf(
        resources / 'trivial.pdf', sym, '--force-ocr', env=spoof_tesseract_noop
    )
    assert p.returncode == ExitCode.ok, err
    assert (outdir / 'out.pdf').stat().st_size > 0, 'target file not created'


def test_livecycle(resources, no_outpdf):
    p, _, err = run_ocrmypdf(resources / 'livecycle.pdf', no_outpdf)

    assert p.returncode == ExitCode.input_file, err


def test_version_check():
    from ocrmypdf.exec import get_version

    with pytest.raises(MissingDependencyError):
        get_version('NOT_FOUND_UNLIKELY_ON_PATH')

    with pytest.raises(MissingDependencyError):
        get_version('sh', version_arg='-c')

    with pytest.raises(MissingDependencyError):
        get_version('echo')


@pytest.mark.parametrize(
    'threshold, optimize, output_type, expected',
    [
        [1.0, 0, 'pdfa', False],
        [1.0, 0, 'pdf', False],
        [0.0, 0, 'pdfa', True],
        [0.0, 0, 'pdf', True],
        [1.0, 1, 'pdfa', False],
        [1.0, 1, 'pdf', False],
        [0.0, 1, 'pdfa', True],
        [0.0, 1, 'pdf', True],
    ],
)
def test_fast_web_view(
    spoof_tesseract_noop, resources, outpdf, threshold, optimize, output_type, expected
):
    check_ocrmypdf(
        resources / 'trivial.pdf',
        outpdf,
        '--fast-web-view',
        threshold,
        '--optimize',
        optimize,
        '--output-type',
        output_type,
        env=spoof_tesseract_noop,
    )
    with pikepdf.open(outpdf) as pdf:
        assert pdf.is_linearized == expected


def test_image_dpi_not_image(caplog, spoof_tesseract_noop, resources, outpdf):
    check_ocrmypdf(
        resources / 'trivial.pdf',
        outpdf,
        '--image-dpi',
        '100',
        env=spoof_tesseract_noop,
    )
    assert '--image-dpi is being ignored' in caplog.text