Mikolaj Tutak wrote:
1. Print charts: there is no (?) generic options to print chart on Z paper with X columns and Y rows and square/hexagonal shape. It could be very useful. Now I generate chart like this:
targen -v -w -d3 -f216 CHART printtarg -v -i ss -r -p148x105 CHART
and print it enlarged to fit A5 paper, it's not very comfortable and clear path ;)
I usually use the ss setting for generic charts. Use the -a option in printtarg to create specific patch sizes.
2. Reading results: Color Mouse included software can communicate spectrophotometer and write measurement to the file. Format can be changed and adjusted a bit, but it have to be manually reformatted for argyll ti3 format and merged with data form ti1 file. Maybe it's a good idea to add an option to 'printread <http://www.argyllcms.com/doc/printread.html>' to read CSV or similar generic file, not only hardware tools?!
There are a number of conversion tools already. See if logo2cgats (for instance) can be altered to work with the Color Mouse files. If you send me some example files (the .ti1, .ti2 and the Color Mouse CSV file), I can look at this.
Another option with non-supported instruments is to use the printread -x mode, where you can feed in the Lab or XYZ value for each patch.
3. Finally I do all the tasks manually using OpenOffice Calc and other tools, results are a bit better than with scanner and Kodak Q60 color target ;-) But IMO print are still too warm. It's my personal opinion, but I looking for option to manipulate white balance with argyll. Can I force profiler to generate "cooler" profiles?
I went through the exercise of comparing an (RGB) profile for my Epson 1800 generated using an IT8 chart and my Epson 4990 scanner, and the profile using the SpectroScan. Now I did cheat slightly in that the Kodak IT8 chart had a custom reference file for it, but the results were remarkably similar (on gloss paper). Subtly different, but hard to pick apart.
Unfortunately I haven't made any "creative" or manual color tools for Argyll - the main intent has been to do everything by the numbers. If I were to add a tweak control, the question is, what should it do ? If a curve was applied down the neutral axis, what shape should it have ? What colorspace should it be in ?
I have been trying to collect a small set of charts that have been read with scanners and with a spectrometer, to at least give me something to go on in answering the above questions with regard to correcting the sorts of neutrality errors that arise using a scanner.
The idea would be to have a test chart (or a program that generates a test chart) of neutral and near neutral patches, labelled with their delta E from ab 0,0, print them out with (the new) cctiff through the profile in questions, and then pick the most neutral patch by eye, and feed those numbers into "profile" as correction factors. It's pretty easy for RGB, it's a bit more tricky for CMYK, because there have to be two sets of numbers, one for low K, and another for high K.
Graeme Gill.
