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Aug
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revised CMYK JPEGs extracted from PDF appear inverted
added 151 characters in body
Apr
28
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Apr
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comment CMYK JPEGs extracted from PDF appear inverted
This is a great reference, thanks!
Apr
23
answered CMYK JPEGs extracted from PDF appear inverted
Jan
12
comment CMYK JPEGs extracted from PDF appear inverted
Great info, but unfortunately this is not an ICC issue. The image contains the proper ICC profile, the pixels are just reversed.
Dec
2
comment CMYK JPEGs extracted from PDF appear inverted
@horatio - I've updated my question with additional information.
Dec
2
revised CMYK JPEGs extracted from PDF appear inverted
added 211 characters in body
Nov
30
comment CMYK JPEGs extracted from PDF appear inverted
@horatio ~ And how would that be lossless? Unless the file output was a different format, that would result in further entropy, which was strictly prohibited by the parameters laid out in the question. You're missing the point. The question is not "How to invert a lot of files," but "How to fix inverse-CMYK encoding losslessly."
Nov
28
revised CMYK JPEGs extracted from PDF appear inverted
added 25 characters in body
Nov
28
comment CMYK JPEGs extracted from PDF appear inverted
@horatio ~ I'm not sure where you're getting your information. The JPEG format supports an arbitrary number of planes, and CMYK JPEGs are readily available. What part of the workflow are you referring to? The DCTDecode streams are written to disk, and when opened in an editor (including Photoshop), they appear color-inverted. There isn't any more workflow.
Nov
27
comment CMYK JPEGs extracted from PDF appear inverted
@e100 ~ I am not certain that actually re-encoding the values losslessly is possible, due to rounding errors and the inherent lossiness of the JPEG spec.
Nov
27
comment CMYK JPEGs extracted from PDF appear inverted
@e100 ~ The DCTDecode stream is extracted bytewise. I would presume the actual number of files to process is irrelevant. A process that works on one would work on all.
Nov
27
revised CMYK JPEGs extracted from PDF appear inverted
added 50 characters in body
Nov
27
comment CMYK JPEGs extracted from PDF appear inverted
@e100 ~ How exactly would that be batch automated?
Nov
27
revised Color loss during colorspace conversions
deleted 7 characters in body