问题
I am trying to generate a PDF using a library called wkhtmltopdf to create an RGB pdf. I am then using ghostscript to convert it to a CMYK format, however, the black text that is in the pdf is not pure black [cmyk(0,0,0,1)].
The black color is visible in other channels.
The command for ghostscript is:
gs -dBATCH -dNoOutputFonts -dNOPAUSE -dTextBlackPt=1 -dBlackPtComp=1 -sTextICCProfile -dNOCACHE -sDEVICE=pdfwrite -sProcessColorModel=DeviceCMYK -sColorConversionStrategy=CMYK -sOutputICCProfile=ps_cmyk.icc -sDefaultRGBProfile=srgb.icc -dOverrideICC=true -dRenderIntent=1 -sOutputFile=cmyk11.pdf test-rgb-cmyk.pdf
Any help would be massively appreciated! Been at this for a few days now. Thanks!
Ghostscript version: 9.26 Example pdf: https://drive.google.com/file/d/1nSM05b0O6fEb_0Z1rr2REbOPQAdwolTA/view?usp=drivesdk
回答1:
Almost all the switches you are using will have no effect with the pdfwrite device, they are specific to rendering devices (bitmap output). In particular the -dTextBlackPt, -dBlackPtComp and TextICCProfile will do nothing.
In order to properly colour manage the conversion you need to specify input and output ICC profiles. I'm in a meeting at present but if memory serves you need to alter the default Gray, RGB and CMYK profiles that Ghostscript uses.
Really I'd need to see an example file (as simple as possible) and it would obviously be useful to know which version of Ghostscript you are using. If its not the current version then I'd suggest you upgrade anyway.
来源：https://stackoverflow.com/questions/56486986/black-color-showing-on-cmy-channels-when-converted-to-cmyk-using-ghostscript