Patent ID: 8884980

Claim:
A computer-implemented method for digital hair coloring comprising: obtaining a starting image I of a subject including a hair region; calculating a matte defining a calculated foreground area of said starting image, wherein said calculated foreground area comprises said hair region, wherein said matte comprises an alpha mask α composed of alpha values corresponding to each pixel of the starting image; obtaining a target color distribution, wherein said target color distribution is based on a target hair color, wherein said target color distribution is a distribution in an ellipsoidal volume of a three-dimensional color space, wherein target principal ellipsoid axes of said target color distribution are estimated using principal component analysis; generating a recolored image T(I) by applying a color transformation based on said target color distribution to said calculated foreground area of said starting image using nonlinear transformation; and generating an output image O from alpha blending of said recolored image with said starting image resulting in changing of color of said hair region, wherein said output image is generated from an equation comprising O=αT(I)+(1−α)I.