I've noticed what you guys are calling "pixels" since I was a kid. It's most prominent in a dark room, and is usually a bright green colour. If I let it go on it's own, it'll run along the contours of the room and coalesce into expanding and contracting green that is very fluid. I've been able to manipulate it to a degree, even into faces and objects, etc. I've just not been able to actually literally see a static image of something. Ever since picking up drug habits, I've acquired HPPD, and I now experience this phenomenon the entire time I am awake whether I like it or not. I've also got a lot of "visual snow" that looks like a lot of multi coloured grains constantly buzzing, like the black and white ones you'd see on a TV, but again multi coloured. It's actually pretty much exactly like the image you (Alter) posted with the blue expanding in it. The blue is like what the green I mentioned earlier is. I've managed to changed the colours before, but it's kind of difficult. Everything is much easier to do if I've taken some sort of hallucinogenic though.