alt.hn

6/22/2026 at 1:20:26 AM

Remaking BBC test cards to teach you video processing

https://www.youtube.com/watch?v=U_6HxPkrgcg

by unleaded

6/24/2026 at 8:40:58 AM

I like the part where they talk about the color perception space. The color perception space has itself multiple representations, according to the distance definition you are taking. The one shown in the video is the CIEXYZ (1931). Since human perception is non linear, there are other definitions which take into account those non linearities to make the space more "Hilbertian", such as CIELAB (https://en.wikipedia.org/wiki/CIELAB_color_space), or CIELUV (1976, https://en.wikipedia.org/wiki/CIELUV). This article sums up well the different representations : https://math.stackexchange.com/questions/1777699/color-space...

by GL26

6/24/2026 at 3:16:03 PM

When I look at these sorts of diagrams, it seems as if the colours don't blend continuously. Generally I see three rays extending out from the white point that seem much whiter than the surrounding colours, and also a line perpendicular to the "purple" edge which is darker. What's up with that?

by zahlman

6/24/2026 at 11:19:57 AM

This video has the greatest "Sources and references" section I think I've seen in a YouTube video - 16 videos, over 50 webpage links, and 4 references that don't have links.

by helsinkiandrew