一种基于自适应多窗口选择的NEDI改进算法  

AN IMPROVED NEW EDGE-DIRECTED INTERPOLATION ALGORITHM BASED ON ADAPTIVE MULTIPLE WINDOWS SELECTION

作　　者：刘楠[1] 毕笃彦[1] 李权合[1] 

机构地区：[1]空军工程大学航空航天工程学院陕西西安710038

出　　处：《计算机应用与软件》2013年第9期53-56,共4页Computer Applications and Software

基　　金：国家自然科学基金项目(61175029);国防科技重点实验室基金项目(9140C610301080C6106);航空科学基金项目(20101996009)

摘　　要：经典NEDI(New Edge-directed Interpolation)算法计算插值系数时使用矩形模板,存在不能兼顾模板内像素方向性的缺陷,而且在插值时仅使用单一窗口,可能导致高低分辨率上协方差不满足几何对偶性,造成插值后图像边缘存在比较明显的振铃现象,影响视觉质量。针对该问题,采用中心位于待插值点的圆形模板计算插值系数,并进一步依据最小均方差判决准则提出一种自适应多窗口选择方法来确定最佳的插值窗口。实验结果表明,相对于传统的插值方法,该算法能够更好地保持边缘信息,插值结果具有良好的视觉效果,峰值信噪比也得到了明显提高。Classic NEDI （new edge-directed interpolation） algorithm uses rectangular template to calculate the interpOlation coefficients, this has the limitation of not taking into account the directivity of the pixels within template, besides, it just uses a single window while interpolating, which may lead to the mismatch of covariance in high-resolution and low-resolution, and cause obvious ringing effect in image edges after interpolating and impact the visual quality. In light of these problems, in this paper, we adopt a circular template with the centre in the interpolating point to calculate the interpolation coefficients, and further present an adaptive multiple windows selection approach according to the judging criterion of minimum means square error to chose the most matchable interpolation window： Experimental result indicates that relative to traditional interpolation methods, the proposed algorithm can better preserve the edges information, the interpolation results have better visual effect：, and the peak signal noise ratio （PSNR） is noticeably improved as well.

关 键 词：图像缩放 NEDI 插值系数 多窗口 峰值信噪比 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]