- low-rgb->rgb8! float*_in uchar*_outprocedure
- low-rgb->hsl! float*_in float*_outprocedure
- low-rgb8->rgb! uchar*_in float*_outprocedure
- low-rgb8->hsl! uchar*_in float*_outprocedure
- low-hsl->rgb! float*_in float*_outprocedure
- low-hsl->rgb8! float*_in uchar*_outprocedure
Low-level versions of rgb->rgb8 etc.