Does there exist a plugin that can replace each pixel with a custom image, centered to that pixel and with the appropriate luminance and tint, with the option to screen blend (or multiply, etc) where they intersect? I've tried to illustrate here with some enlarged mockups.
As an example input, some scattered pixels in white, grey, red and blue.
Pixels replaced with a custom image of a white box. The color pixels become color boxes, which add to magenta where they intersect.
Replaced with a gradient line.
I figure you could do all sorts of interesting blur, bloom, bokeh and star filter effects with this method, I just have no idea what it would be called or if it exists!