Auto white balance using dynamic histogram matching for AMOLED panels

Abstract

This paper presents a novel method of Auto White Balance (AWB) using Dynamic Histogram Matching (AWB-DHM) for AMOLED panels. Existing methods of AWB based on histogram matching always chooses a specific channel based on pre-defined criteria such as channel having maximum cumulative intensity among the R, G and B channels etc.,. Then match the histograms of other two channels with the chosen channel. Since the channel selection is always constant, for a given algorithm, when AWB is applied for images under varying illumination conditions they are prone to color distortion. On the contrary, the proposed approach in this paper analyzes the histogram distribution for each color channel (R, G and B) of an input image and then dynamically decides the best fit channel for histogram matching. Hence, this approach eliminates color distortion in images under all lighting conditions and enhances the visual quality by increasing the Overlap Area (OA). This method increases the Overlap Area (OA) of three channels by at least 18% and contributes to additional power savings of 11% especially for AMOLED panels when the best fit channel chosen has lower cumulative intensity. Moreover, the proposed method is computationally efficient compared to existing methods.