def test_remove_background(resources, outdir):
# Ensure the input image does not contain pure white/black
with Image.open(resources / 'congress.jpg') as im:
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',
'--plugin',
'tests/plugins/tesseract_noop.py',
)
output_png = outdir / 'remove_bg.png'
ghostscript.rasterize_pdf(
output_pdf,
output_png,
raster_device='png16m',
raster_dpi=Resolution(100, 100),
pageno=1,
)
# The output image should contain pure white and black
with Image.open(output_png) as im:
assert im.getextrema() == ((0, 255), (0, 255), (0, 255))
def test_deskew(resources, outdir):
# Run with deskew
deskewed_pdf = check_ocrmypdf(
resources / 'skew.pdf',
outdir / 'skew.pdf',
'-d',
'--plugin',
'tests/plugins/tesseract_noop.py',
)
# Now render as an image again and use Leptonica to find the skew angle
# to confirm that it was deskewed
deskewed_png = outdir / 'deskewed.png'
ghostscript.rasterize_pdf(
deskewed_pdf,
deskewed_png,
raster_device='pngmono',
raster_dpi=Resolution(150, 150),
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 rasterize(pdf, pageno, png):
if png.exists():
print(png)
return
ghostscript.rasterize_pdf(
pdf,
png,
raster_device='pngmono',
raster_dpi=Resolution(100, 100),
pageno=pageno,
rotation=0,
)
def test_mono_not_inverted(resources, outdir):
infile = resources / '2400dpi.pdf'
opt.main(infile, outdir / 'out.pdf', level=3)
rasterize_pdf(
outdir / 'out.pdf',
outdir / 'im.png',
raster_device='pnggray',
raster_dpi=Resolution(10, 10),
)
with Image.open(fspath(outdir / 'im.png')) as im:
assert im.getpixel((0, 0)) == 255, "Expected white background"
def rasterize_pdf_page(
input_file,
output_file,
raster_device,
raster_dpi,
pageno,
page_dpi,
rotation,
filter_vector,
):
ghostscript.rasterize_pdf(
input_file,
output_file,
raster_device=raster_device,
raster_dpi=raster_dpi,
pageno=pageno,
page_dpi=page_dpi,
rotation=rotation,
filter_vector=filter_vector,
)
return output_file
def test_rasterize_size(francais, outdir):
path, pdf = francais
page_size_pts = (pdf.pages[0].MediaBox[2], pdf.pages[0].MediaBox[3])
assert pdf.pages[0].MediaBox[0] == pdf.pages[0].MediaBox[1] == 0
page_size = (page_size_pts[0] / Decimal(72), page_size_pts[1] / Decimal(72))
target_size = Decimal('50.0'), Decimal('30.0')
forced_dpi = Resolution(42.0, 4242.0)
rasterize_pdf(
path,
outdir / 'out.png',
raster_device='pngmono',
raster_dpi=Resolution(
target_size[0] / page_size[0], target_size[1] / page_size[1]
),
page_dpi=forced_dpi,
)
with Image.open(outdir / 'out.png') as im:
assert im.size == target_size
assert im.info['dpi'] == forced_dpi
def test_rasterize_rotated(francais, outdir, caplog):
path, pdf = francais
page_size_pts = (pdf.pages[0].MediaBox[2], pdf.pages[0].MediaBox[3])
assert pdf.pages[0].MediaBox[0] == pdf.pages[0].MediaBox[1] == 0
page_size = (page_size_pts[0] / Decimal(72), page_size_pts[1] / Decimal(72))
target_size = Decimal('50.0'), Decimal('30.0')
forced_dpi = Resolution(42.0, 4242.0)
caplog.set_level(logging.DEBUG)
rasterize_pdf(
path,
outdir / 'out.png',
raster_device='pngmono',
raster_dpi=Resolution(
target_size[0] / page_size[0], target_size[1] / page_size[1]
),
page_dpi=forced_dpi,
rotation=90,
)
with Image.open(outdir / 'out.png') as im:
assert im.size == (target_size[1], target_size[0])
assert im.info['dpi'] == (forced_dpi[1], forced_dpi[0])
