The flash almost always occurs while moving, but it seems tied to very specific camera positions. In the screenshots above, I found a certain position that I could move the camera into that would cause the glitch even when I wasn't moving.

It is possible that the effects are simply making the glitch more visible. I am using edge detection+monochrome+negative . I have had the problem both in windowed and full screen mode.

I was able to catch another picture of the problem. In this screenshot, I am simply using edge detection. You'll notice in the top left corner of the screen, a portion of the sky hasn't had the filter applied to it yet.