Some applications need to present groups of images in an attractive way for their users.
One nice way to present images is to create a mosaic effect. Several images are displayed as tiles next to each other, so the users can see many images at once.
This PHP class can show tiled images using the mosaic effect. There is one main background image and all the group images are displayed over that image using transparency in a way that looks like small glasses over the background image, causing great visual impression.
The class can generate the mosaic effect in a PDF document that can be printed. Using the same algorithm it could eventually generate the same mosaic effect outputting as an image.
The package comes with a nice screenshot of the output so you can see the effect in practice.