1. An image analyzer comprising: an image partitioner configured to find a partition point that divides a received image into four sub-images each having a pre-selected activated pixel count; a recursion processor configured to (i) apply the image partitioner to an input image to generate a first partition point and four sub-images and to (ii) recursively apply the image partitioner to at least one of the four sub-images for at least one recursion iteration to generate at least one additional partition point and additional sub-images; and a formatter configured to generate a features representation of the input image in a selected format, the features representation being based at least in part on the partition points.