Use of Dichromatic Reflection Model to Estimate the Illuminants of Landscape Images for Background Replacement

Background replacement using a landscape image can generate realism when video chatting, making the user feel as if they are actually at the location shown in the landscape. In our previous study, to enhance this realism, we proposed a background replacement method using a chromatic adaptation transform. This method fits the color of a foreground image to the illuminant of the landscape used as the new background image, and can enhance the realism of the video chat. However, if an incorrect illuminant of the landscape is obtained based on gray world assumption, the method might not enhance realism because it fits the foreground color to this illuminant. In this paper, we propose an illuminant estimation method that uses the dichromatic reflection model, and describe the appropriate parameters for this method. Our experimental results suggest that landscape illuminants can be estimated by the proposed method better than a gray world assumption.