Test target for CLF processing accuracy tests

In the CLF VWG meeting today we discussed the need for a test image that we will use for validating CLF processing accuracy. Here are some proposed requirements for the target:

  1. Has a good range of colors, probably one or more log spaced grid/cube of some size. In my own targets, I’ve used three grids to cover normal, dark/negative, and super-bright areas separately to avoid having large numbers of extreme values that are not very helpful.
  2. Covers a wide range of values. I will propose distributing them similar to half float values.
  3. Includes +/- Infinity and NaN.
  4. Includes some shallow gradients to look for banding, both visually and on a waveform monitor.
  5. Includes some solid patches large enough for easy locating/samping with an eye-dropper type tool.
  6. No IP issues, may be contributed to open source / creative commons.
  7. Not too big since it will make it easier to store/share lots of copies of it after processing through multiple CLFs.
  8. Some wide-range ramps in various pure colors (R,G,B,C,M,Y, neutral).

Would anyone like to add any other requirements? Does anyone have any targets that they could propose for this?

I am forming a sub-group to work on this deliverable, if anyone would like to join, please get in touch.


Doug Walker
CLF Implementation VWG chair