Make a collage from a collection of images:

Assign relative weights to the images:

Overlay an image with a second image:

• If the background of the overlaid image is not transparent, it will obscure the image below. Use the option setting Background->None with Graphics and Rasterize to make images with transparent backgrounds.

Specify the position of the overlaid image:

Combine an array of images into a single image:

• Component images must all be the same size.