Hi guys. Thanks for the feedback.
A "retired" color is one that is not currently available through LEGO's official Pick-a-brick store, but is still available through bricklink, or other 3rd party retailers.
I am sorry that the demo site isn't working for you. It is still in beta and uses some bleeding edge browser technology. I will look into it.
Our goal is to create a website ( brickapic.com ) where you can upload an image and purchase the kit including instructions, bricks, etc. So, the software will be server side and available via any modern web browser.
Some of the important software features.
There are a few steps to creating a good lego Mosaic.
1) Scale and crop. This is pretty basic, but the software will provide a way to crop and zoom into an image so that people don't have to do this ahead of time in an external image editor.
2) Posterize. This is the technical term for taking a true-color image and decreasing the number of colors that it uses (44 in our case) in a way that preserves the most details. This is where we really shine compared to the alternatives, because we use some good dithering algorithms and perceptual color math to get a really good effect.
3) Brick placement. We could use all 1x1 bricks, but that is tedious and more expensive than it needs to be, so we have an algorithm that intelligently places the bricks to maximize the size of the brick and minimize the total number of parts, to save on cost.
4) Instructions. We are still working on this part a little, but we will have some software that will produce some easy to follow instructions for assembling the mosaic.
I hope that helps explain the project a little more.
-Jake