Research On And Adaptive Photo Mosaic Technique And Its Application

Non photorealistic rendering technique is a brand new branch in computergraphics. Its application can make up many defects inherent in traditionalphotorealistic rendering, such as one hand in architecture and machinery, the other inart. NPR has evoked people great interest in recent years. There have been manypapers and techniques about NPR. But, as a new research field, NPR will developcontinuously in many respects.Here aimed at a key techniques of NPR technique——photo mosaic, wepresent a adaptive photo mosaic algorithm, and apply it for a kind of abstract andsimple photo mosaic with NPR effect. On the specific research, we employ manyImage Processing Technologies, such as region segmentation, feature extraction. Inview of deficiency in traditional algorithms, we present some new ideas, design andimplement related algorithms with detailed analysis and experiment results. Thespecific responsibilities follow:First of all, in view of the importance of image grid segmentatiom in the processof generating photo mosaic, focusing on the high distortion caused by conformalrectangular blocks segmentation, forming a new visual effect of photo mosaic byintroducing image segmentation based on quadtree. It is a new idea to consider thealignment on regions, and have a great increasing in similarity, descreasing thedistortion.Secondly, in order to retrieve the matching tile images, we need a more accurateimage retrieve algorithm, here proposed an image retrieve algorithm based on humanvisual system. By making full use of human visiual system, we construct a newcomputation rule on weight coefficient, and use different algorithms according to theparameters of different regions adaptively in the retrieval process, which improves theaccuracy of the retrieve.Thirdly, to ensure the similarity between the mosaic rendering result image andthe source image, in view of the deficiency in traditional color adjusting algorithm,here proposed a mosaic rendering color adjusting algorithm based on color transfer.Here employed the color transfer algorithm to adjust higher order color in photo mosaic, improving the distortion question of traditional color adjusting algorithm, andverified the performance through experiments.