Video contrast adjustment using spatio-temporal histogram specification

Histogram specification based image contrast enhancement algorithms have been studied extensively. A recently presented 2-D histogram specification (2-D HS) scheme defines 2-D histogram from an input image and derives pixel-value mapping relationship using the 2-D histogram. In this paper, we apply the conventional 2-D HS to the temporal domain to adjust the spatio-temporal contrast of video signals. Our 2-D histogram is thus defined in the spatio-temporal domain, and the pixel values are adjusted using the spatio-temporal 2-D HS. Experimental results show the effectiveness of the proposed method.