[Openexr-devel] Floating Point Questions (and a C Question)

[Vincent Olivier]

Hi guys,

I have three questions for (any of) you:

1. What happened to the "C" linking interface that is mentioned in the documentation? I couldn't find any C-compatible export in the header files. Did I miss something?
2. Since most programming languages do not have a "half" primitive, it is fair to say that since most pixel arithmetics are done in 32-bit single precision "float" space, the 16-bit half-precision storage is actually lossy? If so, are there any studies on how (human- or machine-) perceptually lossy this is, in practice, both for in-camera images and computer-generated ones?
3. Am I right to say that only half of the exponent field of the variable precision number representation will ever be used since a valid channel pixel value ranges from -1 to 1? If so, is that handled by the lossless compression schemes?

I might be completely off with all of this, but theses are the questions that stick after some reading of the documentation and the code.

Thanks!

Vincent