Python PIL incorrectly decoding TIFF colors (using incorrect colorspace)?

问题

When I use PIL==1.1.7 to load TIFF images, it seems to get the colorspace wrong:

What's going on?

• The .tiff was created using convert test.jpg test.tiff (but seems to happen with other tiff files too)
• It can be found at: http://hul.wolever.net/dump/test.tiff
• The output when PIL.Image.DEBUG = True:

>>> from PIL import Image
>>> Image.DEBUG = True
>>> Image.open("/tmp/test.tiff").show()
tag: ImageWidth (256) - type: short (3) - value: (560,)
tag: ImageLength (257) - type: short (3) - value: (401,)
tag: BitsPerSample (258) - type: short (3) - value: (8, 8, 8)
tag: Compression (259) - type: short (3) - value: (7,)
tag: PhotometricInterpretation (262) - type: short (3) - value: (2,)
tag: FillOrder (266) - type: short (3) - value: (1,)
tag: DocumentName (269) - type: ascii (2) - value: /tmp/lemur.tiff
tag: StripOffsets (273) - type: long (4) - value: (8, 9282, 18712, 28312, 38000, 48730, 59052, 70406, 83010, 95978, 108967, 121029, 133136, 145555, 157411, 168289, 179433, 191157, 202954, 214664, 226914, 238919, 250547, 261871, 273282, 284453)
tag: Orientation (274) - type: short (3) - value: (1,)
tag: SamplesPerPixel (277) - type: short (3) - value: (3,)
tag: RowsPerStrip (278) - type: short (3) - value: (16,)
tag: StripByteCounts (279) - type: long (4) - value: (9274, 9430, 9600, 9688, 10730, 10322, 11354, 12604, 12968, 12989, 12062, 12107, 12419, 11856, 10878, 11144, 11724, 11797, 11710, 12250, 12005, 11628, 11324, 11411, 11171, 2541)
tag: XResolution (282) - type: rational (5) - value: ((1207959552, 16777216),)
tag: YResolution (283) - type: rational (5) - value: ((1207959552, 16777216),)
tag: PlanarConfiguration (284) - type: short (3) - value: (1,)
tag: ResolutionUnit (296) - type: short (3) - value: (1,)
tag: PageNumber (297) - type: short (3) - value: (0, 1)
tag: JPEGTables (347) - type: undefined (7) - value: ????C??

???}!1AQa"q2??#B??R??$3br?  
%&'()*456789:CDEFGHIJSTUVWXYZcdefghijstuvwxyz???????????????????????????????????????????????????????????????????????????
tag: YCbCrSubSampling (530) - type: short (3) - value: (2, 2)
*** Summary ***
- compression: jpeg
- photometric_interpretation: 2
- planar_configuration: 1
- fill_order: 1
- size: (560, 401)
format key: ('II', 2, 1, 1, (8, 8, 8), ())
- raw mode: RGB
- pil mode: RGB

回答1:

This is most likely due to the fact that your TIFF images contain compressed JPEG data generated by Adobe Photoshop, that uses a special marker to indicate the correct colorspace. I guess PIL doesn't know this marker (at least, in a TIFF-embedded JPEG), so it assumes that the image is in YCbCr colorspace (which we can see on the screenshot).

See the detailed answer here, I believe it's exactly your case.

The possible solution for you is to convert your JPEGs with other methods (without compressed JPEG data). For example, if PIL manages to open your JPEGs correctly, you can rewrite the TIFF with PIL:

from PIL import Image
img = Image.open("test.jpg")
tif = Image.new("RGB", img.size)
tif.paste(img)
tif.save('result.tiff')

来源：https://stackoverflow.com/questions/12900656/python-pil-incorrectly-decoding-tiff-colors-using-incorrect-colorspace