A Pixel's Color

(This post was first published with Collabora on Jan 25, 2022.)

A Pixel's Color

My work on Wayland and Weston color management and HDR support has been full of learning new concepts and terms. Many of them are crucial for understanding how color works. I started out so ignorant that I did not know how to blend two pixels together correctly. I did not even know that I did not know - I was just doing the obvious blend, and that was wrong. Now I think I know what I know and do not know, and I also feel that most developers around window systems and graphical applications are as uneducated as I was.

Color knowledge is surprisingly scarce in my field it seems. It is not enough that I educate myself. I need other people to talk to, to review my work, and to write patches that I will be reviewing. With the hope of making it even a little bit easier to understand what is going on with color I wrote the article: A Pixel's Color.

The article goes through most of the important concepts, trying to give you, a programmer, a vague idea of what they are. It does not explain everything too well, because I want you to be able to read through it, but it still got longer than I expected. My intention is to tell you about things you might not know about, so that you would at least know what you do not know.

A warm thank you to everyone who reviewed and commented on the article.

A New Documentation Repository

Originally Wayland CM&HDR extension merge request included documentation about how color management would work on Wayland. The actual protocol extension specification cannot even begin to explain all that.

To make that documentation easier to revise and contribute to, I proposed to move it into a new repository: color-and-hdr. That also allowed us to widen the scope of the documentation, so we can easily include things outside of Wayland: EGL, Vulkan WSI, DRM KMS, and more.

I hope that color-and-hdr documentation repository gains traction and becomes a community maintained effort in gathering information about color and HDR on Linux, and that we can eventually move it out of my personal namespace to become truly community owned.