Texture filtering
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In computer graphics, texture filtering is the method used to map texels (pixels of a texture) to points on a 3D object. There are many methods of texture filtering, and developers must make a tradeoff between rendering speed and image quality when choosing a texture filtering algorithm.
To better understand the concepts involved, one should think of a pixel as a discrete sample of a continuous function rather than a block on a grid that makes up an image.
The fastest method is to take a point on an object and look up the closest texel to that position. The resulting point then gets its color from that one texel. This is sometimes referred to as nearest neighbor filtering. It works quite well, but can result in visual artifacts when objects are small, large, or viewed from odd angles.
More sophisticated techniques combine more than one texel per point. The most often used algorithms in practice are bilinear filtering and trilinear filtering using mipmaps. Anisotropic filtering and higher-degree methods, such as quadratic or cubic filtering, result in even higher quality images.