I have an application I have developed which is generating RGB PNG images with text on them via imageMagic, like so:
convert -size 1000x1000 -density 300 xc:white -pointsize 24 \ -fill "rgb(0,0,0)" -annotate +500+500 'Josh Test' Jtest.png
It's working great. However I need to be able to generate CMYK output as well, the same images, but in CMYK rather than RGB. InkScape can't do this. I thought I could just use a CMYK color:
convert -colorspace cmyk -density 300 xc:white -pointsize 24 \ -fill "cmyk(0,0,0,0)" -annotate +500+500 'Josh Test' Jtest.pdf
However the resulting image is not 100% black, but 100% cyan, 100% magenta, 100% yellow and 0% black. Actual colors look even worse. This is because ImageMagic does all drawing in an RGB space and converts to CMYK:
Drawing requires the RGBA color model. Internally, images are stored as RGB(A) or CMY(A)K.
I cannot generate RGB images and convert to CMYK, the colors won't be right. They must be CMYK the whole way through. How can I generate CMYK images under linux?