Legacy ImageMagick Discussions Archive

If you use -strip, you remove the profile. see http://www.imagemagick.org/script/comma ... .php#strip. You would then get displayed differences. The profile is important.

If the printer needs a CMYK profile, then you would need to convert to that. I do not know what profiles are acceptable to your printing operation. The best suggestion is to do some test prints with the sRGB profile and see if that works.

However, I do not believe that PNG supports CMYK directly. It may allow a CMYK profile. That is something that some one else, such as glennrp, would need to answer.

PNG doesn't support CMYK pixels, and therefore a CMYK profile would be senseless because the profile has to match the pixels, although libpng currently might not reject it.

so to summise, a CMYK png is a no no for Print purposes? Or is a cmyk png not possible for display purposes ?, a CMYK jpeg is a no no for display purposes, a CMYK gif ? not sure why anyone would bother a CMYK bitmap ? and of course a CMYK tiff which is fine ...
Is there any way in a script to enable output based on input ? something like CMYK PSD only keep colorspace for tiff the other formats need to be converted to sRGB ...
RGB PSD do convert i need to be able to 'pivot' based on input but am struggling with how to script this in ubuntu 12.04 .....

why is it not OK to convert all formats to use sRGB profile?

If it works, don't complicate your processing.

good question ! i did ask myself this , although the image is perfect on screen and in PSHOP, when printed its washed out the blacks have disappeared ... this is from our original CMYK PSD converted to profile swop and converted again to the sRGB.icc..
if we print the original its blacker ... is there anyway to compensate for this ? Or is this just a bad bit of IM coding on my part ?

the below command
+profile '*' -profile /media/psf/DATA/USWebCoatedSWOP.icc -profile /media/psf/DATA/sRGB_IEC61966-2-1_black_scaled.icc -black-point-compensation -intent Relative

You code looks fine. but I have not used blackpoint compensation or -intent relative (usually default -intent which I believe is perceptual for png output)

thanks fred .. any reason an icc profile to icc profile print job would be any different ?

briandenks wrote:thanks fred .. any reason an icc profile to icc profile print job would be any different ?

Not sure what you mean? If there is a profile for the image, the printer should respect that profile. But you may need to find out what the printer accepts for profiles. Are you printing this yourself or sending to a printing service?

printing it ourselves, but a fairly high spec workgroup canon printer..

but we are doing CMYK file without profile, add profile convert to sRGB add profile then finally to the printer ..
The difference is the print is lighter with less black, perhaps cuase im using black_scaled_icc ?

I don't know about black_scaled_icc I use sRGB.icc. But I have little experience with printing using profiles.

I don't understand the question, so ignore this if it isn't helpful.

High-end Canon printers come with printer driver software and profiles. You need to use (within the driver) the appropriate profile for the printer and paper stock.

The question is: what files may be sent to the printer driver? It will almost certainly accept TIFF, PNG, JPG etc that are sRGB, or with any other profile. It may accept PSD files. In any case, the driver should convert from the profile in the file to the one specified by the user, that is appropriate for the paper etc.

I've had some preliminary luck converting a CMYK jpg using -profile sRGB.icm -profile printer'sprofile.icc, I assume this first converts to sRGB then applies the specific printer profile. The results have been dead-on color wise as changing the mode from cmyk>rgb in PS (for some reason PS is ok going from cmyk>rgb, but rgb>cmyk buggers the color).