1. My assignment: to make some test patterns that will appear on Blu-ray, the authoring system of which requires 8-bit YUV 4:2:2 files of some kind (I've been using AVI files as rendered by CS5.5 and now CS6 Cloud)

2. What I'm starting with: RGB still frames (usually TIFFS) with pixel values corresponding the digital video standard (16-235). To be sure that each pixel has the expected value, these still frames were calculated algorithmically.

3. The problem: YUV files made from such still frames of black-to-white RGB gradients end up with repeated pixel values or skipped pixel values (the gradient is not "monotonic"). I am assuming that this is because of round-off effects in the formulas used to get from RGB to YUV (I may be wrong on this). 

4. Restrictions as to the solution: a. must be software based, b. must be free or very cheap, c. must produce the EXACT results I need. i.e. PERFECT gradients in Y, no skipped values, no repeated values -- and in a file format usable by the Blu-ray authoring system.

5. I guess what I need is a file-conversion system in which I can simply designate the contents of one color channel of an RGB signal (which are identical in black-to-white gradients) as Y and which will stick in the appropriate values in for U and V (0 in the case of monochrome test patterns). Anybody come across something like this? Is there a way to do this with anything contained in CS5.5 or CS6?

--Sixtus