Don't repeat image plane width/height computation
Don't repeat image plane width/height computation

Change-Id: Ia58759dec0c6d5e5d0e91166e2abf5204c3217f3

GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom