This Optical Illusion of Multiplying Dogs Is a Crash Course In How Digital Image Editing Works

Kensuke Koike’s Top Breeder illusion
Gif: Kensuke Koike (

Slice up a photo of a dog and reassemble it, and you’ll be left with two images of the same pup. Slice those photos up again, and somehow you’ll then have four images of that doggo. It seems like an impossible optical illusion, but this neat trick is actually a very basic demonstration of how image editing apps work.


To be fair to a complicated application like Photoshop, Kensuke Koike’s fun video is a gross simplification of how a digitized image is reduced in size. Complex algorithms are used to ensure that when a pixelated image is shrunk, the results are sharp while lines and edges remain smooth.

But slicing this real-life dog photo both vertically and horizontally essentially turned it into a compilation of smaller pixels. And when you throw away every other pixel in an image, the results are half as large as the original, but still completely recognizable, if the pixels are small enough.


This Is My Display Name

I’m confused.

Optical illusions, are, well...optical illusions.

This is exactly what it looks like. How is it an optical illusion?