Hi all!

Any way to get a feature "convert image to CMYK and save as.." for users?
My parents-in-law run a small-time magazine, and want a better way of managing the growing library. We have several mac's and pc's and up to 6 users, using one Q-nap home server. Hoping Zenphoto is what im looking for, but it needs to be able to full-fill some criteria. We need Tiff images in the CMYK colour space to be able to print correctly though. Is it possible?

The GD library does not support CMYK conversion, if I'm not mistaken. You would need to use ImageMagick/Imagick or GraphicsMagick/Gmagick, and to that end you could create a small script using one of these to accomplish what you want.

With ImageMagick or GraphicsMagick, you would need to have PHP make a command line call to the appropriate program using `exec()` with `convert -colorspace CMYK` to convert.

With Imagick, you could use something like this:

`
function convertCMYK($filename) {
$image = new Imagick($filename);
$image->setImageColorspace(Imagick::COLORSPACE_CMYK);
$image->writeImage($filename); // this will replace the old file!
}
`
This function will take a filename and convert that file into CMYK, replacing the old one.

The Imagick function can be directly converted to Gmagick by simply replacing Imagick with Gmagick (in the two cases).

After that, it's just a matter of printing out a link to the image, which would be simple to code in PHP or add to the function above. This is all provided that your server supports one of the above.

Thank you for your feedback. Is there nothing like this allready scripted? As I am pretty green when it comes to any kind of coding language.. There must be more people like me who need CMYK's for printing?

No, generally Zenphoto is a web gallery CMS where CMYK is really not important. If people print anything that will most likely be desktop printer who don't really understand CMYK anyway.

For real offset/digital printing I doubt that converting via imagick or the like generates really good printable images (I admit I actually don't know how the quality is). You should do these thingsg better with real image editors. For example what about color profiles which are quite important?

yeah, I was thinking that too.. but still hoping. Yeah we'd use the fogra29 CMYK colour profile, but might be simpler to get some freeware 3rd party software to let us do the conversion locally on each computer/mac.

I think it would even be saver to use some proper tool like Photoshop or the like as you would have more control.

But photoshop is expencive, and with 2 macs and 3 pc's, thats just to many bags of cash to be able to change the colourspace. Thanks anyway

Well, there are of course other tools that are more affordable that Photoshop...;-)

there are even some decent free programs. gimp can do cmyk if you also install the separate+ plugin. if you're looking for something else you can try the list here.

Of course, if quality does not matter, just print from jpeg. Seems strange to be penny wise and pound foolish with a business.