Monday, August 8, 2011

Your Colors or Mine?

[Please note that this post is part of a series describing my first wobbly steps into the world of ICC color profiles. The aim is to build an ICC color profile editor from scratch. Seeing how I started this project with no knowledgde whatsoever on the subject, it's wise to realise that some of my findings described in these posts are incorrect. The incorrect conclusions are usually corrected in later posts. For the whole series in one go, click here.]

So what have I been doing in the meantime?

Well, I dove into color profiles and their mysteries!

Not very exciting unless you're a geek.

It started when I decided it was time to try to calibrate my screen.

I have been using a color profile mind you, but that's always been a more visual oriented approach.

So I bought myself a Spyder3 - which is a colorimeter you attach to the screen - and let it do its tricks to determine what the profile actually should be for my screen (if you're a complete novice, google 'color profiles' to find out why you need them).

Low and behold... it worked... but the results were doubtful to say the least.

The screen became too dark, and the pretty neutral gray I had created visually, turned into a dirty yellowish brown. Only with my color imagination stretched beyond borders I could visualise 'gray'... but only because I knew it should be...

That wasn't right.

No matter how I fiddled with the software, the profile didn't budge. Every time again those horrible grays.

And anyone who's got knowledge about this subject will tell you that neutral grays are important.

In the end I went back to my visual profile. The grays actually look gray in that one, and on sight I adapted the profile slightly towards the created profile by the Spyder (using Windows Color Calibration functionality).

I concluded the hardware of my laptop is probably too limited for a truly proper profile.

Then I thought: why not fine tune the profile the Spyder produces? Perhaps I can tweak it a bit and get rid of those yellowish brown grays that way...

Then I discovered that's not really easy, because there's no good software around to do that.

Actually there is, but you have to pay through the nose for it. Kodak produces some modules, but those range from 600 to 6000 dollars. Incredible, just for tweaking a color profile. There's more manufactures out there, but prices are equally staggering.

At you can download a profile inspector for free, which allows some manual editing, but it's not intuitive at all, and more importantly: you don't see the immediate result.

So then I thought: I'll write my own editor.

Kind of a bold thought actually, with me knowing virtually nothing about color profiles or how they operate.

Even more daring when I tell you that I dont want to build just a profile editor, I also want to see what my photo will look like with an adapted profile, preferably on the fly. So it needs to have proofing.

Currently - after frustrating days - I'm now finally getting somewhere.

I first concentrated on reading the profile and extracting the header information. Similar like the application on Then I realised I needed proofing, so I dove into the actual use of color profiles under Windows 7. I won't bore you with the details, but I'm currently capable of converting bitmaps between different color profiles, exactly the thing I need. Well, not exactly, because now I have to make it work with at least JPGs... another hurdle... but I'm getting somewhere.

Then if that actually works on my screen, I will have to start designing a user interface for the data in the profile. And that means understanding first what's going on inside of them and how the math works.

There's comprehensive documentation out there, so I still have good hopes, but it will be a while before I have a functioning editor (if ever).

I'll keep you posted...

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