Plain -fuzz -transparent white color-keyed every pixel in the whole
image close enough to white by color distance — including an
antialiased blend inside the artwork itself (where the light beam meets
the window frame), which punched a stray transparent hole there, and
still left a faint opaque fringe ring around the outer edge since the
binary cutoff didn't fully consume the antialiasing ramp.
Redone with a flood fill seeded from a corner pixel instead: only
transforms the background region actually connected to that seed (the
four corners + thin white border, confirmed contiguous), leaving
disconnected internal antialiased pixels untouched. Then eroded the
alpha channel by ~2px to consume the remaining boundary ramp cleanly.
Verified against both dark and light composited backgrounds, and
confirmed the beam/window-frame area is no longer punctured.
Puranjay Savar Mattas
09e1ab8f65