openmp for X-Trans v0.1
More perf on x-trans: if() => ?:
A few major improvements:
- changed two if's into linear operations in "homogeneity maps from derivatives" loop
- changed / compacted FORC loop in cielab
- for non-OpenMP version: changed ndir variable to const int and buffer to static (proved unproductive in openmp...)
Added correction: cielab3 for three colors, cielab when do not know.
Still other performance improvements, especially large outer loop in xtrans_interpolate which is now parallelized
Merge pull request #112 from yama1968/master

openmp for X-Trans v0.1