After you helped me sort out my printing issues (
http://forum.luminous-landscape.com/index.php?topic=124335.80) I got back to scanning and I'm pretty much back to square one with that. Like I mentioned in that thread, I came up with a set of scripts to do some systematic analysis of every profile I could create. Happy to share, but I have a feeling you have your own system in place that's more automated.
1. I took a ColorChecker that I printed and measured with my spectrophotometer.
2. Scanned the ColorChecker and my three targets (IT8, CC24, DCCSG) using Epson Scan w/ no color management, and with Gamma 2.2 but a reset histogram; VueScan RAW 48bit, RAW 24bit, and with Color None and DeviceRGB as output.
3. Wrote a script to generate every combo of Argyll profiles from the scans and used i1Studio where it would let me (it didn't like the RAW images).
4. Recorded the RGB of the corresponding test ColorChecker print for each scan method and wrote another script to take my ICCs and run the RGB through them using Argyll's icclu tool.
5. Then I took those Lab numbers and wrote another program in Python to output the ∆E(2000) between the resulting Lab values and the Lab of the original print.
I've attached a sample of my ∆E for Epson Scan and a few different profiles vs. my printed ColorChecker if you're curious. (The image with the patches have Lab rounded to whole numbers unfortunately, but it's still pretty representative of my issues even with other photos.) I didn't notice significant difference between the different scan methods. In some cases the RAW worked better, in others a more normal scan was preferable. My custom target I made with Argyll on the same paper yielded the best results for the ColorChecker I printed… but didn't work at all for my photo collection I'm trying to scan.
I'd be curious to see if you have luck getting a general profile that's good enough or if you're only satisfied with custom profiles for each paper you're trying to reproduce.