Fixed bug when multiplying by one-channel image
Fixed bug when multiplying by one-channel image

git-svn-id: c578352ef3581197c7d0052ca74e10c73f7d7a72@102 f3e031b0-0bc6-11df-b730-f17d7b42d8b9

mit-gfx/ImageStack,mit-gfx/ImageStack,mit-gfx/ImageStack,mit-gfx/ImageStack