Temporal constraint relationship for use in an image segregation for frames of a video

摘要

A soft, weighted constraint imposed upon image locations temporally spaced in frames of a video, can be used to provide a more accurate segregation of an image into intrinsic material reflectance and illumination components. The constraint is arranged to constrain all color band variations between the image locations into one integral constraining relationship.

主权项

1. An automated, computerized method for processing multiple image files of a video, comprising the steps of:
providing at least two image files, each depicting an image having image locations, in a computer memory; selecting image locations i from a first image file k and j from a second image file k−n, k−n being temporally spaced n frames from image file k in the video; setting a temporal constraint between the image locations according to a log color space equation:
wnij*(Mi−Mj)=wnij*(αijVij+(1−αij)Bij), wherein Mi and Mj are log color space values for the material reflectance component of the image locations i and j, respectively, Vij is a difference vector to provide a gradient magnitude defined by Vij=Ii−Ij, where Ii and Ij are log color space values corresponding to color values recorded in the image files, for the color and intensity of the selected image locations i and j, respectively, Bij is a component of Vij not aligned with illumination change between the selected image locations and is a vector defined by Bij=Vij−(Vij·N), where N is a BIDR normal, αij is a scalar value based upon a smooth scalar function α that varies from 0 to 1, as a function of a degree of change expressed by Ii−Ij corresponding to one of an illumination change or a material reflectance change, and wnij is a temporal constraint confidence weight calculated as wnij=sn*wij, wherein wij is a constraint weight and sn is a scaling factor determined as a function of the n frames between the image file k and the image file k−n frame of the video; and solving the log color space equation to identify an intrinsic component of the selected image locations.