Yes, and to be perfectly clear, the color matrix is all identity except for the alpha row [0 0 0 21 -9]. This is stretching the alpha range so that many of the

Yes, and to be perfectly clear, the color matrix is all identity except for the alpha row [0 0 0 21 -9]. This is stretching the alpha range so that many of the semi-transparent areas outside of the original blob that were generated by the gaussian blur are now completely opaque. (It's similar to a thresholding operation, but there are some middle values that survive.)