Everything you Ever Wanted to Know about Collage Mosaics

Introduction

As the above image shows, using images as mosaic tiles can create some pretty interesting pictures. The technique used to do so is quite simple. Segment the target (large) image into small, discrete sections, and for each section search through a database of possible tile images and pick the best one. This technique leaves some undesirable effects. First, the image not-only looks "tiled", but even pixelated. Since all of the tiles are the same size, the image is very grid-like. Secondly, the tiles themselves are not that interesting. In order to achieve a resolution high enough to accurately depict the target image, the size of the tiles often becomes so small that by themselves they lose almost all meaning.

For me, the above painting by Salvador Dali is a much more interesting image than the mosaic of Homer firing a gun. Because the smaller images that make up the mosaic, namely the woman staring out the window, are intelligible and interesting, the whole image becomes much more complex and fascinating.
Inspired by "Gala Contemplating the Mediterranean Sea which at Twenty Meters becomes a Portrait of Abraham Lincoln," the goal of this project is to create mosaics that interesting up close and from far away. That is to say, the tiles themselves should be intelligible and interesting, and the large mosaic image should appear to arise from the collection of smaller images as if it was and emergent behavior.

As stated before, the two main problems with popular mosaic techniques are

1. Pixelation
2. Incoherence of individual tiles

Sections

1. Intro
2. The Approach
3. First Method Results
4. Second Method Results
5. Backing away to 20 meters...
6. Meta Results