Readings on color management

Color management in the production pipeline is a tough topic. A really tough one. And a crucial one too. Unfortunately not only is this an important and difficult topic, but it also seems to me that except maybe for people working on AAA games or heavy budget film industry, most have little knowledge on the matter, when they’re not just completely unaware of the issue.

The issue that image capturing devices, screens and printers all have different color characteristics (said simply: what you scan, photography or film will not look the same depending on the capturing device used, and a same image will look different depending on the display or printing device too).

The issue that they have a capturing or display range usually far from what the human vision is capable of, and by “far” you must understand by orders of magnitude (said simply, the average human can perceive way more contrast than a camera is able to capture, differentiate much more colors than a screen is able to display, and on top of that there are colors an average screen is just absolutely unable to render, like the orange of your fluorescent highlighter for example; this one is my favorite example actually :) ).

The issue that screens and image formats use a non linear representation leading to severe errors in colors unless it is taken into account when manipulating images (said simply, ignore gamma correction in your rendering and your lighting will be wrong, ignore it when you resize images and they will look wrong too).

I just wish it were more simple and “just worked”. But until then we have to deal with it. So here goes the list of readings on this nonetheless very interesting topic.

On color management:

On gamma correction:

  • Gamma error in picture scaling: this article shows how bad things can go when image manipulation softwares don’t take gamma into account, and gives a glimpse of how widespread the problem is.
  • The Value Of Gamma Compression: I like this short article a lot, as it shows in a quick a clear way how a bad gamma management can ruin a rendering.
  • Gamma and Lighting Part 1, Part 2, Part 3: this three parts article from the same blog explains how they handle the issue in the production pipeline of X-Plane.
  • GPU Gems 3, Chapter 24 – The Importance of Being Linear: this article explains how to take gamma into account in your rendering pipeline; while an interesting read, I think it doesn’t make the issue obvious enough (as I find the different illustrations to be equally bad looking).
  • Gamma FAQ: this FAQ is quite dated but still helps understanding the origin of gamma correction and avoid confusion between various concepts (there is also a Color FAQ from the same author).

Update: this 4mn video explains quite convincingly the need for gamma correction.

On tone mapping:

Have a good read!

Update: this lengthy presentation of GDC 2010 (quoting: “The presentation is basically four 20 minute presentations crammed into 55 minutes.”), by John Hable, covers several of these topics.

Skateboard, urban exploration and light

Skateboard, urban exploration and light: this combination makes a surprisingly warm atmosphere. There is no soundtrack in this short by Juan Rayos, the only music is the sound of the skater, Kilian Martin, performing in this big abandoned building.

The natural light of the Sun through the windows, the dust getting up in the air as the skate hits the wooden floor, the emptiness of the place, all build a very warm and quiet mood, while on the opposite the raw editing conveys all the tension due to the difficulty to achieve the tricks.

A lot of care is shown in the composition and the use of light. Most shots are flawless in that regard.

The Breitling Jet Team

This one is for flight enthusiasts.

The Breitling Jet Team (Patrouille Breitling) was founded in the early 80s and had its name changed a couple of times as its sponsor changed. According to the Wikipedia article, Breitling invested in 2003 and allowed the team to grow from a four ships formation to a seven ships one.

In 2010 the paint scheme of the aircrafts was redesigned, and since then various videos have been recorded and made available. For anyone interested in aerobatics, they’re a delight to watch. In the first of these two you can hear the team leader driving the execution, giving it a moody atmosphere. The team performs on a regular basis, especially in Europe, so you might be interested in checking its display dates.

Noah takes a photo of himself every day for 12.5 years

Noah Kalina has been taking a self portrait every day for over twelve years, and uploaded yesterday on Youtube a new time-lapse video of this work in progress. There are a couple of such videos on Internet, but this one is the longest time span I am aware of. During seven minutes, you can not only see how his face evolves as he ages, but also get a glimpse of his outfit style as well as his professional and personals lives.

A raytracer under a hundred lines of C++

On his website Kevin Beason presents a Monte Carlo ray tracer written with 99 lines of C++, generating a picture of a Cornell box with global illumination. Beyond the interesting experiment and the fact it can generate a binary of 4kB, I find very valuable the fact there are slides explaining all the code.