Playing again with a bit of Processing code which recursively cuts an image into smaller rectangles until the variation of color in the rectangle is below a chosen threshold.
Click through for larger version.
First, an image I shot a while back of some leaves on a plant in my house. I shot this with a f1.8 50mm wide open, so the depth of field is tiny.
Here is the same image processed with a Processing applet I wrote which subdivides the image into smaller rectangles until the variation of color in the rectangle is sufficiently small (click through to Flickr to see the large versions). This gives a variable size, irregular, mosaic effect, emphasized by the exaggerated black borders on the rectangles.