M. J. Maher (Ed.): ASIAN 2004, LNCS 3321, pp. 248–258, 2004. © Springer-Verlag Berlin Heidelberg 2004 A Novel Texture Synthesis Based Algorithm for Object Removal in Photographs Feng Tang, Yiting Ying, Jin Wang, and Qunsheng Peng State Key Lab of CAD & CG, Zhejiang University, 310027 Hangzhou, P. R. China {tang, ytying, jwang, peng}@cad.zju.edu.cn http://www.cad.zju.edu.cn Abstract. Natural images and photographs sometimes may contain stains or undesired objects covering significant portions of the images. Inpainting is a method to fill in such portions using the information from the remaining area of the image. In this paper, we propose a novel photograph editing framework that utilizes texture synthesis techniques. Major contributions of our algorithm are: 1) a constraint-based candidate patch searching method which limits the searching within neighboring region with similar texture; 2) a metric of Coherence Confidence for selecting the best fit candidate preventing error accumulation and propagation; 3) integration of graphcut optimization to make the seam visually invisible. Experiments show that our system can efficiently handle different cases especially large regions in complex background. 1 Introduction In practice, we often meet with such problems as old photos spoiled by ink or old paintings full of scratches after long time reservation. Besides, photos may contain undesired large objects to be removed, for example, a passing-by person may drop into the view when a photo is taking. Although these two types of problems originate from different scenarios, they are commonly known as inpainting. How to robustly and efficiently solve both problems remains a challenge. Several works have addressed these problems. For the first type of problems, which contains scratches or small missing regions, there are diffusion based and filter based methods. Bertalmio [1]-[2] filled in the tiny spoiled regions by propagating information from the outside of the masked region along level lines (isophotes). Reference [3] proposes Total Variational (TV) inpainting algorithm that invokes Euler-Lagrange equation and applies anisotropic diffusion [5] inside the inpainting domain based on the contrast of the isophotes. Oliveira [6] filtered the input image using a Gaussian convolution kernel to remove the undesired flaws. Yet such algorithms account for only small local regions. Artifacts of blurs may occur when they are applied to large region of inpainting. For the second type of problems, a kind of synthesis based methods has been proposed. Liang et al. [7] composed the texture of a large region by selecting