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src/img2pdf_test.py: we create our own channel-switching ICC profile

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Johannes 'josch' Schauer 2020-08-09 22:03:47 +02:00
parent 692b54ac67
commit 11907242a5
Signed by: josch
GPG key ID: F2CBA5C78FBD83E1
1 changed files with 200 additions and 42 deletions
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src/img2pdf_test.py Normal file → Executable file
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@ -352,11 +352,13 @@ def compare_ghostscript(tmpdir, img, pdf, gsdevice="png16m", exact=True, icc=Fal
(tmpdir / ("gs-1." + ext)).unlink()
def compare_poppler(tmpdir, img, pdf, exact=True):
def compare_poppler(tmpdir, img, pdf, exact=True, icc=False):
subprocess.check_call(
["pdftocairo", "-r", "96", "-png", str(pdf), str(tmpdir / "poppler")]
)
if exact:
if icc:
raise Exception("not exact with icc")
subprocess.check_call(
[
"compare",
@ -368,18 +370,38 @@ def compare_poppler(tmpdir, img, pdf, exact=True):
]
)
else:
psnr = subprocess.run(
[
"compare",
"-metric",
"PSNR",
str(img),
str(tmpdir / "poppler-1.png"),
"null:",
],
check=False,
stderr=subprocess.PIPE,
).stderr
if icc:
psnr = subprocess.run(
[
"compare",
"-metric",
"PSNR",
"(",
"-profile",
"/usr/share/color/icc/ghostscript/srgb.icc",
"-depth",
"8",
str(img),
")",
str(tmpdir / "poppler-1.png"),
"null:",
],
check=False,
stderr=subprocess.PIPE,
).stderr
else:
psnr = subprocess.run(
[
"compare",
"-metric",
"PSNR",
str(img),
str(tmpdir / "poppler-1.png"),
"null:",
],
check=False,
stderr=subprocess.PIPE,
).stderr
assert psnr != b"0"
psnr = float(psnr.strip(b"0"))
assert psnr != 0 # or otherwise we would use the exact variant
@ -445,9 +467,11 @@ def compare_pdfimages_tiff(tmpdir, img, pdf):
(tmpdir / "images-000.tif").unlink()
def compare_pdfimages_png(tmpdir, img, pdf, exact=True):
def compare_pdfimages_png(tmpdir, img, pdf, exact=True, icc=False):
subprocess.check_call(["pdfimages", "-png", str(pdf), str(tmpdir / "images")])
if exact:
if icc:
raise Exception("not exact with icc")
subprocess.check_call(
[
"compare",
@ -459,18 +483,38 @@ def compare_pdfimages_png(tmpdir, img, pdf, exact=True):
]
)
else:
psnr = subprocess.run(
[
"compare",
"-metric",
"PSNR",
str(img),
str(tmpdir / "images-000.png"),
"null:",
],
check=False,
stderr=subprocess.PIPE,
).stderr
if icc:
psnr = subprocess.run(
[
"compare",
"-metric",
"PSNR",
"(",
"-profile",
"/usr/share/color/icc/ghostscript/srgb.icc",
"-depth",
"8",
str(img),
")",
str(tmpdir / "images-000.png"),
"null:",
],
check=False,
stderr=subprocess.PIPE,
).stderr
else:
psnr = subprocess.run(
[
"compare",
"-metric",
"PSNR",
str(img),
str(tmpdir / "images-000.png"),
"null:",
],
check=False,
stderr=subprocess.PIPE,
).stderr
assert psnr != b"0"
psnr = float(psnr.strip(b"0"))
assert psnr != 0 # or otherwise we would use the exact variant
@ -504,13 +548,7 @@ def tiff_header_for_ccitt(width, height, img_size, ccitt_group=4):
)
###############################################################################
# INPUT FIXTURES #
###############################################################################
@pytest.fixture(scope="session")
def alpha():
def alpha_value():
# gaussian kernel with sigma=3
kernel = numpy.array(
[
@ -548,6 +586,103 @@ def alpha():
return alpha
def icc_profile():
PCS = (0.96420288, 1.0, 0.82490540) # D50 illuminant constants
# approximate X,Y,Z values for white, red, green and blue
white = (0.95, 1.0, 1.09)
red = (0.44, 0.22, 0.014)
green = (0.39, 0.72, 0.1)
blue = (0.14, 0.06, 0.71)
getxyz = lambda v: (round(65536 * v[0]), round(65536 * v[1]), round(65536 * v[2]))
header = (
# header
+4 * b"\0" # cmmsignatures
+ 4 * b"\0" # version
+ b"mntr" # device class
+ b"RGB " # color space
+ b"XYZ " # PCS
+ 12 * b"\0" # datetime
+ b"\x61\x63\x73\x70" # static signature
+ 4 * b"\0" # platform
+ 4 * b"\0" # flags
+ 4 * b"\0" # device manufacturer
+ 4 * b"\0" # device model
+ 8 * b"\0" # device attributes
+ 4 * b"\0" # rendering intents
+ struct.pack(">III", *getxyz(PCS))
+ 4 * b"\0" # creator
+ 16 * b"\0" # identifier
+ 28 * b"\0" # reserved
)
def pad4(s):
if len(s) % 4 == 0:
return s
else:
return s + b"\x00" * (4 - len(s) % 4)
tagdata = [
b"desc\x00\x00\x00\x00" + struct.pack(">I", 5) + b"fake" + 79 * b"\x00",
b"XYZ \x00\x00\x00\x00" + struct.pack(">III", *getxyz(white)),
# by mixing up red, green and blue, we create a test profile
b"XYZ \x00\x00\x00\x00" + struct.pack(">III", *getxyz(blue)), # red
b"XYZ \x00\x00\x00\x00" + struct.pack(">III", *getxyz(red)), # green
b"XYZ \x00\x00\x00\x00" + struct.pack(">III", *getxyz(green)), # blue
# by only supplying two values, we create the most trivial "curve",
# where the remaining values will be linearly interpolated between them
b"curv\x00\x00\x00\x00" + struct.pack(">IHH", 2, 0, 65535),
b"text\x00\x00\x00\x00" + b"no copyright, use freely" + 1 * b"\x00",
]
table = [
(b"desc", 0),
(b"wtpt", 1),
(b"rXYZ", 2),
(b"gXYZ", 3),
(b"bXYZ", 4),
# we use the same curve for all three channels, so the same offset is referenced
(b"rTRC", 5),
(b"gTRC", 5),
(b"bTRC", 5),
(b"cprt", 6),
]
offset = (
lambda n: 4 # total size
+ len(header) # header length
+ 4 # number table entries
+ len(table) * 12 # table length
+ sum([len(pad4(s)) for s in tagdata[:n]])
)
table = struct.pack(">I", len(table)) + b"".join(
[t + struct.pack(">II", offset(o), len(tagdata[o])) for t, o in table]
)
data = b"".join([pad4(s) for s in tagdata])
data = (
struct.pack(">I", 4 + len(header) + len(table) + len(data))
+ header
+ table
+ data
)
return data
###############################################################################
# INPUT FIXTURES #
###############################################################################
@pytest.fixture(scope="session")
def alpha():
return alpha_value()
@pytest.fixture(scope="session")
def tmp_alpha_png(tmp_path_factory, alpha):
tmp_alpha_png = tmp_path_factory.mktemp("alpha_png") / "alpha.png"
@ -659,19 +794,26 @@ def tmp_inverse_png(tmp_path_factory, alpha):
@pytest.fixture(scope="session")
def tmp_icc_png(tmp_path_factory, alpha):
def tmp_icc_profile(tmp_path_factory):
tmp_icc_profile = tmp_path_factory.mktemp("icc_profile") / "fake.icc"
tmp_icc_profile.write_bytes(icc_profile())
yield tmp_icc_profile
tmp_icc_profile.unlink()
@pytest.fixture(scope="session")
def tmp_icc_png(tmp_path_factory, alpha, tmp_icc_profile):
normal16 = alpha[:, :, 0:3]
tmp_icc_png = tmp_path_factory.mktemp("icc_png") / "icc.png"
write_png(
0xFF - normal16 / 0xFFFF * 0xFF,
normal16 / 0xFFFF * 0xFF,
str(tmp_icc_png),
8,
2,
iccp="/usr/share/color/icc/sRGB.icc",
iccp=str(tmp_icc_profile),
)
assert (
hashlib.md5(tmp_icc_png.read_bytes()).hexdigest()
== "d09865464626a87b4e7f398e1f914cca"
== "3058ba4703212fe8c18560e6d1cb61b1"
)
yield tmp_icc_png
tmp_icc_png.unlink()
@ -4249,7 +4391,7 @@ def png_palette8_pdf(tmp_path_factory, tmp_palette8_png, request):
@pytest.fixture(scope="session", params=["internal", "pikepdf", "pdfrw"])
def png_icc_pdf(tmp_path_factory, tmp_icc_png, request):
def png_icc_pdf(tmp_path_factory, tmp_icc_png, tmp_icc_profile, request):
out_pdf = tmp_path_factory.mktemp("png_icc_pdf") / "out.pdf"
subprocess.check_call(
[
@ -4272,7 +4414,7 @@ def png_icc_pdf(tmp_path_factory, tmp_icc_png, request):
assert p.pages[0].Resources.XObject.Im0.ColorSpace[1].Alternate == "/DeviceRGB"
assert (
p.pages[0].Resources.XObject.Im0.ColorSpace[1].read_bytes()
== pathlib.Path("/usr/share/color/icc/sRGB.icc").read_bytes()
== tmp_icc_profile.read_bytes()
)
assert p.pages[0].Resources.XObject.Im0.DecodeParms.BitsPerComponent == 8
assert p.pages[0].Resources.XObject.Im0.DecodeParms.Colors == 3
@ -5319,9 +5461,9 @@ def test_png_palette8(tmp_path_factory, png_palette8_img, png_palette8_pdf):
def test_png_icc(tmp_path_factory, png_icc_img, png_icc_pdf):
tmpdir = tmp_path_factory.mktemp("png_icc")
compare_ghostscript(tmpdir, png_icc_img, png_icc_pdf, icc=True)
# compare_poppler(tmpdir, png_icc_img, png_icc_pdf)
# compare_mupdf(tmpdir, png_icc_img, png_icc_pdf)
# compare_pdfimages_png(tmpdir, png_icc_img, png_icc_pdf)
compare_poppler(tmpdir, png_icc_img, png_icc_pdf, exact=False, icc=True)
# mupdf ignores the ICC profile
compare_pdfimages_png(tmpdir, png_icc_img, png_icc_pdf, exact=False, icc=True)
@pytest.mark.skipif(
@ -6500,3 +6642,19 @@ def test_general(general_input, engine):
orig_img.close()
except AttributeError:
pass
def main():
normal16 = alpha_value()[:, :, 0:3]
pathlib.Path('test.icc').write_bytes(icc_profile())
write_png(
normal16 / 0xFFFF * 0xFF,
"icc.png",
8,
2,
iccp="test.icc",
)
if __name__ == "__main__":
main()