Color matching techniques for video mosaic applications

Color matching techniques are proposed to merge two or more video inputs of smaller sizes into one single larger output video with a wider field of view for video mosaic applications. The main challenge is to remove the seam lines between image boundaries due to the different color tone of the inputs. In this paper, color differences between input images are first compensated using the polynomial-based contrast stretching technique. Then, a linear filtering technique is adopted to remove the seam lines. The algorithms are developed in both the pixel domain and the DCT (discrete cosine transform) domain. The second approach is attractive for its lower computational complexity. Experimental results demonstrate that the color-matching problem can be satisfactorily solved in the compressed domain even when the DCT blocks of original input images are not aligned and also for the images taken with camera movement as long as image registration is done in advance. The proposed approach is applicable for MPEG2 video.