On Tue, Sep 8, 2015 at 2:42 PM, Mick <michaelkintz...@gmail.com> wrote: > On the same hardware I noticed that a CMYK photograph converted to sRGB looked > mostly the same (indistinguishable) on Linux, but the sRGB colours were > brighter on MSWindows. >
If everything is working correctly then the CMYK original and sRGB copy should look identical, with the exception of any out-of-gamut colors (as I understand it, very little of CYMK is out-of-gamut for sRGB). If they're not identical then something is wrong, so I wouldn't assume that Linux is at fault (though it could be if the file looks wrong when created on Linux and viewed on another OS, and both OSes are using calibration). Imagine if your original email read like this: On the same hardware I noticed that when I saved my simple OpenOffice document in MS Word format in Linux, and then opened the MS Word file, the text was identical. I tried doing the same thing on both Windows and OSX and in both cases there were lots of weird symbols in the text of the document. What is wrong with my Linux OpenOffice program? Why doesn't it mke my dcment lok lik ths like the other OSes? or like this: On the same hardware I noticed that when I copied a file from a fat32 USB stick to an ext4 USB stick the md5sum of the files remained unchanged. However, if I perform the copy on OSX or Windows the md5sum changes. What is wrong with my linux filesystem drivers? Why doesn't it randomly modify my data when I try to copy it? And, darn it, why does it seem like I never have to reboot the thing to keep it from crashing? Now if one OS or another isn't properly calibrated to your monitor the same file could have different appearances, and if for whatever reason your viewer for the CYMK file applies calibration data differently than the viewer for the sRGB file that would also cause issues. So, the problem might be in the viewing of the files, or in the conversion. Based solely on the testing you performed I can't really be sure which if any of your conversions are being done correctly. The file might appear unchanged on Linux but it could be a result of cancelling errors in the creation and rendering of the file. However, since the whole goal of the conversion process is to avoid making visible changes to the file to the greatest degree possible, I'd tend to look at the other OSes for problems first. -- Rich
