Images are colorized, recolorized, or otherwise manipulated by adding scribbles of a blending medium (such as chrominance) to a measurement medium (such as luminance) of the image. The blending medium propagates from the scribbles according to an intrinsic or geodesic distance that is a function of the measurement medium. Intrinsic distances may be weighted. An effect scribble may produce an effect, such as result data, in the blending medium according to a predefined function. A preprocessing scribble may be converted to one or more effect scribbles which are then propagated. A measurement scribble may propagate so as to alter the intrinsic distances of other scribbles.