A Gaussian pyramid is a technique used in image processing, especially in texture synthesis

Texture synthesis

Texture synthesis is the process of algorithmically constructing a large digital image from a small digital sample image by taking advantage of its structural content...

. The technique involves creating a series of images which are weighted down using a Gaussian average (Gaussian blur

Gaussian blur

A Gaussian blur is the result of blurring an image by a Gaussian function. It is a widely used effect in graphics software, typically to reduce image noise and reduce detail...

) and scaled down. When this technique is used multiple times, it creates a stack of successively smaller images, with each pixel containing a local average that corresponds to a pixel neighborhood on a lower level of the pyramid.