Editing Bilinear interpolation (section)

{{short description|Method of interpolating functions on a 2D grid}}
[[Image:Bilininterp.png|right|thumb|Example of bilinear interpolation on the unit square with the ''z'' values 0, 1, 1 and 0.5 as indicated. Interpolated values in between represented by color.]]
In [[mathematics]], '''bilinear interpolation''' is a method for [[interpolation|interpolating]] functions of two variables (e.g., ''x'' and ''y'') using repeated [[linear interpolation]]. It is usually applied to functions sampled on a 2D [[rectilinear grid]], though it can be generalized to functions defined on the vertices of (a [[Polygon mesh|mesh]] of) arbitrary [[Convex polygon|convex]] [[quadrilateral]]s.

Bilinear interpolation is performed using linear interpolation first in one direction, and then again in another direction. Although each step is linear in the sampled values and in the position, the interpolation as a whole is not linear but rather [[Quadratic function|quadratic]] in the sample location.

Bilinear interpolation is one of the basic [[resampling (bitmap)|resampling]] techniques in [[computer vision]] and [[image processing]], where it is also called '''bilinear filtering''' or '''bilinear texture mapping'''.