After much testing and refinement in an industrial setting, python-colormath has been released to the public under the GPLv3.
What is python-colormath? ==================== python-colormath is a developer-oriented module that abstracts a number of color math operations behind a small set of classes representing color spaces (IE: RGB, CIE Lab, XYZ, and LCH, etc.). Color conversions, delta E comparisons, and density calculations are all relatively involved, but are hid behind the simple API. For example, conversions from RGB to CMY and CMYK are trivial, while conversions from Spectral to LCHab are equally so (even though much more math happens behind the scenes).
Quantitative comparisons of the difference between two colors may be calculated using one of several delta E formulas. Colors are automatically converted to the appropriate comparison color space and the delta E formula returns the result with no real effort on your part.
For those working with spectral power distributions, the module can convert them to color spaces or ANSI/ISO density values. This is particularly useful when trying to minimize the difference in the readings of two different spectrophotometric devices.
It is perhaps best to consider python-colormath as a more advanced, complete version of Python's own colorsys module. The number of supported color spaces, operations, and capabilities far exceeds colorsys (which is simple and minimalistic by design).
Avoid color calculation errors ===================== One of the biggest benefits of this module is that it was designed and implemented by members of the Graphic Communications and print industries. The developers having a formal background in color science leaves you with a very complete, "correct" implementation of color math. Unlike the other color libraries, python-colormath avoids many of the problems with varying types of RGB, color illuminants and observer angles, and many different things that go on behind the scenes.
python-colormath is also rigorously tested through its use in a previously commercial color management system. Additionally, all conversions are unit tested and monitored for deviations wich each change to the codebase. This ensures consistent, repeatable results through each release.
Where is python-colormath? ===================== Getting Started/Website/Development: http://code.google.com/p/python-colormath/
I hope this fairly niche module is useful to someone else out there! -- Gregory Taylor