Bilinear interpolation

In <a href="/facts/Mathematics/pxTouaz4">mathematics</a>, bilinear interpolation is a method for <a href="/facts/Interpolation/8PyetX4f">interpolating</a> functions of two variables (e.g., x and y) using repeated <a href="/facts/Linear_interpolation/galkvRGy">linear interpolation</a>. It is usually applied to functions sampled on a 2D <a href="/facts/Rectilinear_grid/8vDdL4UB">rectilinear grid</a>, though it can be generalized to functions defined on the vertices of (a <a href="/facts/Polygon_mesh/6WLD80ER">mesh</a> of) arbitrary <a href="/facts/Convex_polygon/7x35w610">convex</a> <a href="/facts/Quadrilateral/QCGqrkp2">quadrilaterals</a>.
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 <a href="/facts/Quadratic_function/mKxHIC3U">quadratic</a> in the sample location.
Bilinear interpolation is one of the basic <a href="/facts/Resampling_(bitmap)/qNoeujzm">resampling</a> techniques in <a href="/facts/Computer_vision/Tl2Yyk66">computer vision</a> and <a href="/facts/Image_processing/zenalNCf">image processing</a>, where it is also called bilinear filtering or bilinear texture mapping.

Bilinear interpolation open-in-new

Bilinear interpolation