I don’t think it’s feasable to create the mosaic in AE. Rather use a special sw for this task and import the mosaic into AE. Nice freeware for this is AndreMosaic.Here is a link for the software and a tutorial:
When you have done the mosaic just import into AE. You could apply Fractal Noise in combination with Card Dance and Glow to achieve an impressive implotion of your mosaic to any picture/video. Below a very nice Ayato-Tutorial:
I’m facing exactly the same issue: “After Effects Error: Not enough memory to process this commcand. (8) (25::60)” although 2GB ram and plenty of HD space. Can anybody help?