This is my recent design for folding arbitrary bitmap images as origami tessellations. Unlike using four-sink-base (see Saturn Tessellation), each molecule represents just a single pixel rather than a block of pixels, so all pixels look exactly the same.
The molecule is made from a 4×4 grid, but the size reduction in folded molecule is just 1:2, compared to 1:3 with four-sink base which needs only a 3×3 grid. So, there is bit more precreasing but the resulting tess is larger, and also the collapse is much easier.
The molecule for visible pixels is similar to a square twist, but only the central square is visible. The CP is very simple so someone may have come up with it before, for example it seems Robson Renê Albuquerque got a very similar pattern at the back of his chessboard tessellation [later update: confirmed, this pattern has been known long before, but not as a way of making pixel art].
The empty pixel molecule is just a square twist pulled back to the reverse side of the paper, so in the front just a clean pleat is visible. Anyway, even if the front molecule was already known, I haven’t seen a combination like this used for pixmap images, so I hope this brings something new to the bitmap origami genre.
This is just a quick demo of the technique — I plan to make something bigger and more photography-like using this method when time allows.