目的 原始的破损区域分块划分的图像修复(IIPBDR)算法在修复连接两断裂边界线时,采用的是直线路径,这使得IIPBDR算法不适合修复含有较大曲率边界线的破损图像。针对IIPBDR算法所存在的问题,本研究希望找到一种方法能够求得任意两匹配好断裂边界线之间的光滑曲线路径,并用此曲线路径来代替IIPBDR算法中的直线路径,以对IIPBDR算法进行改进。方法 1) 通过模仿人类的视觉连通性原理提出了光滑拟合模型;2) 采用最小二乘法求取光滑拟合模型的各个参数,进而求得两断裂边界线之间的光滑曲线路径;3) 用该光滑曲线路径来代替IIPBDR算法中的直线路径以修复连接两断裂边界线。结果 基于以上研究,文中提出了“光滑拟合模型的IIPBDR图像修复算法”,并对破损区域较大、结构信息较复杂的破损图像进行了修复实验。和BSCB(Bertalmio, Sapiro, Caselles, Ballester)、Criminisi、IIPBDR算法相比,本文算法所修复图像的PSNR值平均提高2.40 dB,且具有较好的视觉连通性效果、其边界线过渡更加自然。结论 本文改进算法在一定程度上克服了IIPBDR算法不适合修复含有较大曲率边界线的破损图像的缺点。

Objective The original image inpainting algorithm based on partition block of damaged region (IIPBDR) algorithm is not suitable to inpaint a damaged image with large damaged area that contains broken boundaries with large curvature because this algorithm uses a straight path to inpaint the matching broken boundaries in inpainting process. We aim to obtain a smooth curve path between any two matching broken boundaries. This smooth curve path is then used to improve IIPBDR algorithm, instead of a straight path. Method The following steps are performed in this study: 1) A smooth-fitting model that satisfies human visual connecting is proposed. 2) Least square is employed to search all coefficients of this model by using the prior information of the matching broken boundaries. Then, a smooth curve path between two matching broken boundaries is obtained. 3) The smooth curve path, instead of the straight path, is used in IIPBDR algorithm to inpaint two matching broken boundaries. Result “Improved IIPBDR algorithm based on smooth-fitting model” is proposed based on preceding studies. Experimental results indicate that compared with Bertalmio-Sapiro-Caselles-Ballester, Criminisi, IIPBDR algorithms, the improved method can increase peak signal-to-noise ratio value by approximately 2.4 dB, and the inpainted images have better visual effects. Thus, the improved method is more competent than the aforementioned algorithms in inpainting a damaged image that contains broken boundaries with large curvature. Conclusion The proposed algorithm can solve the problem, in which IIPBDR algorithm is not suitable to inpaint a damaged image with large damaged area that contains broken boundaries with large curvature.