计算机应用 ›› 2015, Vol. 35 ›› Issue (10): 2959-2962.DOI: 10.11772/j.issn.1001-9081.2015.10.2959

• 虚拟现实与数字媒体 • 上一篇    下一篇

十字基自适应指导滤波在图像降噪中的应用

权利1, 胡越黎1, 燕明2   

  1. 1. 上海大学 微电子研究与开发中心, 上海 200072;
    2. 上海大学 机电工程与自动化学院, 上海 200072
  • 收稿日期:2015-04-13 修回日期:2015-06-10 出版日期:2015-10-10 发布日期:2015-10-14
  • 通讯作者: 胡越黎(1959-),男,上海人,教授,博士生导师,博士,主要研究方向:图像处理、机器视觉、片上系统、芯片设计,huyueli@shu.edu.cn
  • 作者简介:权利(1989-),女,安徽马鞍山人,硕士研究生,主要研究方向:图像降噪算法;燕明(1992-),男,山东泰安人,硕士研究生,主要研究方向:图像降噪算法。
  • 基金资助:
    国家自然科学基金资助项目(61376028);上海市科委基金资助项目(13111104600)。

Cross-based adaptive guided filtering in image denoising

QUAN Li1, HU Yueli1, YAN Ming2   

  1. 1. Microelectronic Research and Development Center, Shanghai University, Shanghai 200072, China;
    2. School of Mechatronic Engineering and Automation, Shanghai University, Shanghai 200072, China
  • Received:2015-04-13 Revised:2015-06-10 Online:2015-10-10 Published:2015-10-14

摘要: 针对于传统线性滤波器在非边界区域与边界区域有着滤波平滑和边缘保护的矛盾,提出了一种基于指导滤波和十字基相结合的算法。其主要思想是对指导滤波加入自适应偏移量进行调整,保证在边缘结构处细节的保留;普通指导滤波的计算邻域为固定大小的方形窗,在自适应指导滤波算法邻域窗的选取中引入十字基滤波窗,以灰度相似性作为阈值,利用立体匹配的优势,生成大小可自动调节、形状可自适应调整的滤波块,从而实现了滤波性能的提高;偏移量的选取值随滤波窗灰度阈值正比变化,比硬阈值有更好的效果。通过对国际标准图像序列的实验仿真结果比较,表明十字基滤波窗在分块方面有着较高的效率,平滑区域的滤波效果更佳,偏移量的加入使算法在边界区的纹理和细节特征得以保留;较之普通指导滤波算法,提出的十字基自适应指导滤波在峰值信噪比(PSNR)值上提高了约2 dB;通过对实拍图像的处理结果对比表明该算法在实际运用中有着更好的适用性。

关键词: 指导滤波, 十字基框架, 边缘保护滤波, 自适应滤波, 立体匹配

Abstract: Since the contradiction between edge-preserving in homogeneous regions and structure-preserving in the boundary region of an image, a new algorithm combined with cross-based framework and guided filter was proposed. The main idea of the algorithm was adding an adjust offset in guided filter to ensure remaining the edge structure. Usually the fixed size window was used as neighborhood filtering, while the new algorithm employed cross-based framework, which chose a threshold in grayscale similarity. Taking the advantage of stereo matching, the adaptive filtering blocks whose sizes and shapes can adjust automatically were generalized. The adjust offset was proportional to the threshold, which was more robust than a hard threshold. In the simulation experiments of processing international standard sequence, the blocks were generalized by cross-based framework efficiently and effectively, homogeneous regions were smoothed well. The added offset outperforms many other algorithms in terms of sharpness enhancement. Compared to the guided filter, the value of Peak Signal-to-Noise Ratio (PSNR) of the proposed method has been improved by about 2 dB. The test results of real natural picture show that the proposed algorithm has a good future in practical application.

Key words: guided filter, cross-based framework, edge-preserving smoothing, adaptive filtering, stereo matching

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