On Monday 05 March 2007 10:00, [EMAIL PROTECTED] wrote: > How do you people do colour matching? > > It seems to me there are three different bits to worry about, when > trying to print a file. > -- the colours in the file > -- the colours as displayed on the screen (e.g., by ImageMagick or > the Gimp) > -- the colours as printed. > > What do I have to do to my system to be sure that > -- the colours I see on the screen are what's really in the file? > Different monitors look different, even if they're supposed to have > the same Colour Temperature. Without this, one can't easily > adjust colour balance, etc., and have the result what one wants. > -- the colours I get on the printout match what's in the file? > > If it makes any difference, I'm using one of a Xerox 8200DP printer, > an HP Laserjet 4650, and an Epson Stylus Photo 720. The first two > talk PostScript directly; the latter goes via Ghostscript (which has > buttons and knobs for tuning the colour; but I'm thinking of retiring > the inkjet printer --- it's too expensive to run, takes forever to > print anything, only produces good results on coated paper, and the > prints it produces are fragile --- touch them with a wet finger and > they run). The same file looks different printed on the three > printers -- the inkjet looks bluer than the others; the Xerox looks > more orange. > > > So, suggestions for tuning all this stuff, please! I'm using Debian > unstable on AMD64, X86, SPARC and IA64, and my wife's using a powermac > running MacOSX. > > Ideally, I'd like to be able to scan a picture off a slide, adjust the > result and send it to the printer with LPR and get something that's almost > identical to the original; and send the resulting tiff or jpeg to a > friend and have his printer likewise produce something almost > identical to the original.
This is very hard and very expensive (color refs cost $100s to $1000s) The official gimp book gives a chapter to the topic and a poor mans howto: Product manufacturers are very hung up on colours being 'right' so get a commercial Red a green and a blue product. You can get web photos of the product (the file) get samples from the product (the reference) now adjust the screen (file to match the reference) then adjust the print to match the reference Using a bunch of el-cheapo 17" CRT monitors I could not achieve correct gamma/brightness/contrast. It did work on an up-end sony ($2500) and my LCD monitors are good enough to not bother Spelunk gimp docs, this is where it's all hidden James -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
