Nearest-neighbor interpolation
（重定向自Nearest Neighbor Interpolation）
![Nearest neighbor interpolation (blue lines) in one dimension on a (uniform) dataset (red points).](/Images/godic/202501/29/Piecewise_constant.svg0656.png")
![Example of nearest neighbor interpolation of a random set of points (black dots) in 2D. Each coloured cell indicates the area in which all the points have the black point in the cell as their nearest black point.](/Images/godic/202501/29/Coloured_Voronoi_2D.svg0656.png")
![Nearest neighbor interpolation on a uniform 2D grid (black points).](/Images/godic/202501/29/Nearest2DInterpolExample0656.png")
Nearest-neighbor interpolation (also known as proximal interpolation or, in some contexts, point sampling) is a simple method of multivariate interpolation in one or more dimensions.
Interpolation is the problem of approximating the value of a function for a non-given point in some space when given the value of that function in points around (neighboring) that point. The nearest neighbor algorithm selects the value of the nearest point and does not consider the values of neighboring points at all, yielding a piecewise-constant interpolant. The algorithm is very simple to implement and is commonly used (usually along with mipmapping) in real-time 3D rendering to select color values for a textured surface.