The Edit Pseudo Alpha
filter creates an alpha channel for the image based on the image's
first pixel (the upper-left corner pixel). All pixels that have
the same color as this pixel become transparent.
Because only one pixel
color becomes clear, edges of the opaque areas are aliased. The
main use for this filter is when you want to composite a bitmap
whose format does not have an alpha channel.
There is also a layer
event called the
There are no setup options
for this filter.