PreTeXtBook
ImageMagick warning when converting grayscale PDF to PNG
Performing a conversion of latex-image in the sample article, and repeatedly get error messages like the following. But not on every image (many are color). Cursory Googl'ing doesn't suggest a fix that might not harm color images (i.e. a universal argument/switch we can add).
convert-im6.q16: profile 'icc': 'RGB ': RGB color space not permitted on grayscale PNG `tikz-electronics.png' @ warning/png.c/MagickPNGWarningHandler/1667.
This has been there for a long time. I've interpreted it as a harmless warning that you get if your images happen to be black and white.
OK, thanks. Doesn't seem to a problem for me, either. But I figured somebody might get concerned. I was trying to provoke a different error. ;-)
Still good to have it recorded as an issue, with your comment. I'll close it after a while if nothing surfaces.
One question I have is if it's something in the PDF itself that suggests to ImageMagick to use the RGB color space. (Something which can be overruled with the right invocation of convert.)
Because maybe making this go away is not about adjusting how convert is used, but instead is about adjusting how the PDF is built.