In this Adobe Illustrator tutorial you will learn how to create mosaic with square or dotted tiles from any raster image. You can rasterize vector object to apply mosaic effect as well. You can then print your file or use it as basis for future more complex design project. You can tweak the colors and shapes of individual tiles later to achieve even more impressive results.

1. Create a New Document
Press Ctrl+N and choose desired size, resolution and color mode. In this tutorial I use image 640×480 pixels that is suitable for Web design project.

2. Place source image
It’s a good idea to adjust the size of source image according to your projects settings in Illustrator before placing it.
Then choose File->Place, select your source image file and click Place.  To apply mosaic, the image must be embedded, not linked, so don’t forget to uncheck Link check box.

3. Create the Mosaic
Select the image and choose Filter->Create->Object Mosaic.
Set options and click OK. In this case i put 1 px both for width and height tile spacing and 40/30 for number of width/height tiles. I’d recommend checking Delete raster box which gives you immediate result without need to hide source image after applying filter. If you click Use Ratio button you will get square mosaic tiles.

Then click empty space to deselect mosaic tiles.
As soon as this filter doesn’t have a live preview mode you have to experiment quite a lot with settings to get the desired look.

4. Fine tune your mosaic
You can adjust shape, color of each mosaic tile using Direct Selection tool.
In this tutorial i applied Filter ->Stylize->Round Corners (Radius 10px) to get mosaic with dotted tiles.