Separate X and Y passes of blurring like it's done for flat
gaussian blur. This reduces computing difficulty from size^2
to 2*size without any visual changes in matte.
input image to be calculated in some cases, use only actual area which is
needed to calculate current tile.
Seems to be giving some % of speedup. Verified result of keying before
this patch and after this patch and they were identical, so hopefully
now area of interest is indeed correct.
Merge keying node from tomato branch into trunk.
It was considered stable and helpful by Mango team and it'll help
studio pipeline, because nodes would stop disappearing when opening
files in current trunk.
Full information about keying nodes could be found there:
http://wiki.blender.org/index.php/User:Nazg-gul/Keying