Details
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Type: Bug
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Status: Closed
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Priority: Major
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Resolution: Duplicate
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Affects Version/s: 3.0, 4.0.1
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Fix Version/s: 4.1.3
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Component/s: Core/Parsing
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Labels:None
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Environment:ICEpdf 2.7.1
Description
The main text of the document is using cmyk and when using the alternative2 ->
rgb algorithm is a pretty close match to what adobe is generating. However the
Images uses an indexed cmyk colour space which seem to map correctly however we
see heavy greens on some of the images. I've done some tracing and can't find
anything that is out of place.
I suspect there is something incorrect in how we apply the colour profile when
building the image in Stream.makeImageWithRasterFromBytes.
rgb algorithm is a pretty close match to what adobe is generating. However the
Images uses an indexed cmyk colour space which seem to map correctly however we
see heavy greens on some of the images. I've done some tracing and can't find
anything that is out of place.
I suspect there is something incorrect in how we apply the colour profile when
building the image in Stream.makeImageWithRasterFromBytes.
The Stream class has its own CMYK -> RGB conversion algorithm, which we could try replacing with Patrick's alternative2 algorithm. The existing algorithm is not an actual spec one, but is derived from a spec, but modified because certain CMYK image PDF cases were quite different in the brightness/lightness. Potentially there might be some gamma value or rendering intent that should be used to affect the CMYK conversion.