I thought I'd give a shot at adding spot colors to the GIMP TIFF implementation.
If I understand, I need to look at /gimp/plug-ins/common/tiff.c and
add some of the functionality found in /gimp/app/xcf/(?)
(specifically, the portion that assigns the channel color and
opacity), and have tiff.c write the channels to file following the
TIFF 6 spec.
Please correct me if I'm way off-base...
I've see a separate bug (feature request) regarding saving spot
channels in PSD files - perhaps adding the channels to TIFF will be
easier, since the spec is readily available... (and add pretty much
the same functionality).
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