mipmap

In computer graphics, a mipmap (mip being an acronym of the Latin phrase multum in parvo, meaning "much in little") is a pre-calculated, optimized sequence of images, each of which has an image resolution which is a factor of two smaller than the previous. Their use is known as mipmapping.

They are intended to increase rendering speed and reduce aliasing artifacts. A high-resolution mipmap image is used for high-density samples, such as for objects close to the camera; lower-resolution images are used as the object appears farther away. This is a more efficient way of downscaling a texture than sampling all texels in the original texture that would contribute to a screen pixel; it is faster to take a constant number of samples from the appropriately downfiltered textures. Since mipmaps, by definition, are pre-allocated, additional storage space is required to take advantage of them. They are also related to wavelet compression.