In realtime computer graphics, a texture atlas (also called a sprite sheet) is an image containing a collection of smaller images, usually packed together to reduce the atlas size. Atlases can consist of uniformly-sized sub-images, or they can consist of images of varying dimensions. A sub-image is drawn using custom texture coordinates to pick it out of the atlas. In an application where many small textures are used frequently, it is often more efficient to store the textures in a texture atlas which is treated as a single unit by the graphics hardware. Careful alignment may be needed to avoid bleeding between sub textures when used with mipmapping and texture compression.
A texture atlas for a video game
A texture atlas of glyphs
Sprite sheet for the video game Blades of Exile
A human model and "skin" from the MakeHuman project, as viewed in the program, Blender