Image color transfer is a function that maps (transforms) the colors of one (source) image to the colors of another (target) image. A color mapping may be referred to as the algorithm that results in the mapping function or the algorithm that transforms the image colors. The image modification process is sometimes called color transfer or, when grayscale images are involved, brightness transfer function (BTF); it may also be called photometric camera calibration or radiometric camera calibration.
The term image color transfer is a bit of a misnomer since most common algorithms transfer both color and shading. (Indeed, the example shown on this page predominantly transfers shading other than a small orange region within the image that is adjusted to yellow.)