The compostor used a fixed size of 4 floats to hold pixel data. this patch will select size of a pixel based on its type. It uses 1 float for Value, 3 float for vector and 4 floats for color data types. When benchmarking on shots (opening shot of caminandes) we get a reduction of memory of 30% and a tiny speedup as less data transformations needs to take place (but these are negligable. More information of the patch can be found on https://developer.blender.org/D627 and http://wiki.blender.org/index.php/Dev:Ref/Proposals/Compositor2014_p1.1_TD Developers: jbakker & mdewanchand Thanks for Sergey for his indept review.