Blender Git Loki

Cycles Denoising: Get rid of halos around bright edges

Previously, bright edges (e.g. caused by rim lighting) would sometimes get
halos around them after denoising.

This change introduces a log(1+x) highlight compression step that is performed
before denoising and reversed afterwards. That way, the denoising algorithm
itself operates in the compressed space and therefore bright edges cause less
numerical issues.