Reading and Discussion 10: Color 1

by Mike Gleicher on February 15, 2015

Reading and initial Discussion post due: Monday, Feb 23, 11:59pm

Turn-in link: Reading 10 on Canvas

Color is one of those topics that turns out to be more complex than you think it should be. There are all sorts of different directions to come at it: the physics, the optics, the perceptual science, the design aspects, the computational issues, the display reproduction issues, artistic aspects, …

Part of the problem is to weave together a little bit of each of those to meet our needs (being able to design visualizations). The problem is, while there are good deep treatments of most of those topics, there’s nothing that gives you a little bit of each (which is what we want).

Here are the requirements:

For 2/24: You are required to read the color sections of the two textbooks (Ware and Munzner – #1&2 below). They are a little redundant, but I told you we would use most (or all) of the texts. I want you to at least play with ColorBrewer (#7). The paper about it is optional, but it will give you insight as to where it comes from. The rainbow color maps paper is optional (#8), you will probably get the point from the other readings. But, if you cannot answer “why should you avoid the rainbow color map,” read it. Of course, you should also have a sense of “why do people still use it so much.” And, read Stone’s short thing on choosing colors for simple visualizations (#9).

You may want to read some of the other readings (Stone’s slides, the other textbook chapters, the technical stuff).

Yes, that’s 3 required readings (1,2,9), a bit of web playing (7), and some optional readings – but there’s a lot of redundancy, and it can go fast.

The design oriented readings will be required for Thursday.

The discussion: It seems the discussions are more interesting when I don’t prime them too much, but some prompting is helpful.

For your initial posting, list what you read, pick a “favorite” color ramp from Brewer (and explain what it might be used for). And then, start a discussion on how all these different aspects of color (perception, physics, art, reproduction, …) can influence what we need to do as Vis designers. This is the conversation I’d like people to have over the next week. When we get to the designer readings (for Thursday), that should throw some fuel on the fire.

There is a slightly different approach to discussion here: the initial posting and conversation is connected to the Tuesday lecture readings; but we’ll continue to use the same discussion with the Thursday lecture readings – just adding more ideas to the conversation.

Here is a longish list of potential readings… Some of them will required for next time.

The Class:

  • Maureen Stone’s Course on Color would be fantastic. Her course notes are power-point slides that convey a lot of content, but really were meant to augment her presentation. So, while these are a great resource, they are probably not the only thing to look at: PDF for slide handouts, at screen resolution: Part 1 and Part 2. It’s an amazing survey of all the issues from perception, through the different ways to use color. I don’t make them required reading since it’s less clear how well they work by themselves. (optional – but relevant for 2/24)

The textbooks:

  1. Color – Chapter 4 of Visual Thinking for Design by Colin Ware. (required for 2/24)
  2. Map Color and Other Chanels – Chapter 10 of Munzner (really 10-10.3, since 10.4 starts to talk about things other than color). It’s a good broad survey. (required for 2/24)

Some other textbooks:

  1. Chapter 10, Principles of Color, from Thematic Cartography and Geographic Visualization, 2nd edition by Slocum et. al. No we don’t expect you to have this map-making textbook (although it is a great book). We’ve scanned the chapter and placed it into the course reader. This complements the above since it has a little more on the reproduction and representation issues. (optional – a bit redundant)
  2. Chapter 5, The Perception of Color, from Sensing and Perception (a psychology of perception book). This book is even better at discussing how we see color, but doesn’t get into the computational issues as well as the cartography book. It’s probably more of the perceptual science than you want.  (optional – a bit redundant, but good if you want more depth in the perception stuff)

The technical issues in representing color on a computer

  1. Representing Color as Three Numbers (CG&A tutorial, July 2005). Last time, students didn’t like this reading as much as I expected – too much linear algebra, and not enough insight. It’s one of those things that makes more sense after the lecture. (optional, but recommended for 2/24 if you’re curious about the computational issues)
  2. Charles Poynton has an excellent “FAQ on Color” – it’s a bit technical, and there is a lot of video specific stuff. But its the best place to learn about concepts like Color Temperature. It might help you understand why XYZ and xyY and LAB are all different. (optional, but recommended if other readings were making you ask very technical questions about color representations)

Things on choosing color maps:

  1. Cynthia Brewer’s work is a common standard for choosing color sets where you want a sequence of distinct colors (as opposed to continuous ramps). You should play with the ColorBrewer tool to see some of the set suggestions (and use it when you need a set of colors). You should read either a brief explanation or a paper. The paper is a 1990s web page that is showing its age. (experimenting with ColorBrewer required for 2/24 – reading a paper is strongly recommended, although its not a great explanation)
  2. Borland and Taylor. Rainbow Color Map (still) Considered Harmful. IEEE CG&A, March 2007. (ieee page – the university has access, here’s a copy in the reader)
  3. Expert Color Choices for Presenting Data – by Maureen Stone (required for 2/24)
  4. Colin Ware. Color Sequences for Univariate Maps: Theory, Experiments and Principles. IEEE CG&A, September 1988. (pdf here on Colin’s site – the official versions don’t have color!). While I am a big fan of Colin’s work, and I think this inspired a lot of later stuff, it is almost a little redundant with the above. (optional, since it is redundant with the required readings)
  5. Borkin MA, Gajos KZ, Peters A, et al. Evaluation of artery visualizations for heart disease diagnosis. IEEE transactions on visualization and computer graphics. 2011;17(12):2479-88. (official link, unofficial link) – we’ll come back to this paper later, but its an experimental evaluation that shows the pitfalls of ramp design (and other things). (optional – this will be a required reading later in the semester)

Some more design oriented thoughts:

  1. Color and Information – Chapter 5 of Envisioning Information by Tufte. (in protected reader: low res 4MB, hi-res 53M!)
    (will be required for 2/26)
  2. There was a 3 part web tutorial on color for web designers. I really like this since it gets at the artistic and aesthetic issues and how they communicate.
    (part 1 and 2 are required for 2/26, part 3 is strongly recommended)

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