jon-b
asked on
reduce large CMYK file sizes
Just wondering if anyone can explain why CMYK image sizes are so much larger than their RGB counter-parts.
I ask because I'm working with our company logo in illustrator, and CMYK offers the most accurate match - when I convert to our "RGB values", the colours appear a bit darker, slightly different hue - so, I export the .ai as .jpg and use those files where needed (e.g. A4 document headers etc.). The problem is, a CMYK jpg (same dimensions etc.) is up to 8 times the size of it's RGB equivalent - so this can make documents very large (e.g. MS Word and .pdf exports). I've found a great work around - to create a template (for other employees to use), and to 'compress' the image once in MS Word through it's surprisingly effective compression tool. However, I've also provided the CMYK .jpg's as stand-alone files for employees to use when they're working on a unique document that may not already have the header and footer. So two questions:
1) How do I reduce the file size of a CMYK file so that it still prints accurately (and without any noticable compression)
2) Would this mean that my RGB colours need to be re-defined? Appreciate an RGB print is going to come out quite differently, but theoretically on screen, the RGB values should look very close to their CMYK standard (which was the base colour that we used when building our branding)
Any and all advice, much appreciated - many thanks!
I ask because I'm working with our company logo in illustrator, and CMYK offers the most accurate match - when I convert to our "RGB values", the colours appear a bit darker, slightly different hue - so, I export the .ai as .jpg and use those files where needed (e.g. A4 document headers etc.). The problem is, a CMYK jpg (same dimensions etc.) is up to 8 times the size of it's RGB equivalent - so this can make documents very large (e.g. MS Word and .pdf exports). I've found a great work around - to create a template (for other employees to use), and to 'compress' the image once in MS Word through it's surprisingly effective compression tool. However, I've also provided the CMYK .jpg's as stand-alone files for employees to use when they're working on a unique document that may not already have the header and footer. So two questions:
1) How do I reduce the file size of a CMYK file so that it still prints accurately (and without any noticable compression)
2) Would this mean that my RGB colours need to be re-defined? Appreciate an RGB print is going to come out quite differently, but theoretically on screen, the RGB values should look very close to their CMYK standard (which was the base colour that we used when building our branding)
Any and all advice, much appreciated - many thanks!
ASKER
yep - comfortably. That's why I'm wondering if there's a way to compress CMYK files for practical use (in printing and for screen display), without loosing image quality ;)
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ASKER
quite true~ our base was CMYK, but I guess I was just hoping that there was a way of reducing CMYK file size, more than anything - there's no compression tools for this available? I'm sure there must be, MS Word is compressing the image inside the document/program comfortably, without loosing visible print quality...I just want to do this to files outside of MS Word~ Thanks!
jon
jon
Hi jon-b
MS Word is not a commercial print application, I suspect Word just embeds the file and applies its own attributes and discard anything it doesn't need. I don't think the JPEG is extractable with the same properties from Word, so that is not compression it is alteration.
I think the proplem you face is that you are trying to force CMYK files to be something they are not, a bit like if you decide to drive your car backwards from now on and then you try to make it go faster in reverse.
I have not heard of external compression to JPG files, the jpeg format is probably the most efficient compression format there is for images. But as said before you are not using the best methodology if you use CMYK jpegs anyway so your answer lies in modifying your approach.
hth
capt.
MS Word is not a commercial print application, I suspect Word just embeds the file and applies its own attributes and discard anything it doesn't need. I don't think the JPEG is extractable with the same properties from Word, so that is not compression it is alteration.
I think the proplem you face is that you are trying to force CMYK files to be something they are not, a bit like if you decide to drive your car backwards from now on and then you try to make it go faster in reverse.
I have not heard of external compression to JPG files, the jpeg format is probably the most efficient compression format there is for images. But as said before you are not using the best methodology if you use CMYK jpegs anyway so your answer lies in modifying your approach.
hth
capt.
:o)
If the CMYK profile is embedded in a file it can add up to 3MB to the size.