Easy way to swap two ImageBufs.
Allow ImageRec ctr to take NULL for miplevels, meaning 1 per subimage
Safer uninitialized test for ImageBuf, I think
IBA::transpose() and oiiotool --transpose
Use extract_options for action_pattern, allow checker to take height & depth.
IBA::mul and oiiotool --mul : component-by-component multiplication
IBA::channel_sum and oiiotool --chsum
Turn a multi-channel image into a 1-channel image via weighted sum of channels.
IBA::circular_shift, oiiotool --cshift
Fix bug in oiiotools --channels channel renaming
Incorporate KissFFT
ImageBufAlgo::fft and ifft, and oiiotool --fft, --ifft