File Action - Paste in Bitmap
The "Sequence" module in the bitmap variable allows you to paste in a bitmap or import from disk. This is similar to the Specify Numbers module inside the array variable that was used in the Introduction tutorial. The bitmap will be saved inside the script.
The sparsify action is used to speed up computations while we are adjusting parameters. Unchecking the "Sparsify" box will pass the bitmap through unchanged. This module exists for a number of variable types.