图像配准是超分辨率重建中的一个关键问题,直接影响超分辨率重建图像的质量.本文在自适应十字搜索(Adaptive rood pattern search,ARPS)块匹配算法的基础上,根据小波域中各图像之间的相关性,提出一种分层块匹配算法-基于小波变换的改进的自适应十字模式搜索算法(Improved adaptive rood pattern search algorithm based on wavelet transform,W-IARPS),该方法在小波变换域完成匹配宏块的搜索,有效地减少了匹配点的搜索个数,且配准图像的峰值信噪比相比全搜索算法下降不到0.ldB,保持了较高的配准精度.最后采用凸集投影(Projections onto convex sets,POCS)算法对配准后的图像进行超分辨率重建,取得了较好的视觉效果.实验结果表明,该方法具有较高的配准精度和重建效果,算法稳健可靠.
Image registration is one of the key components in super-resolution reconstruction,and it directly affects the quality of the reconstructed image.On the basis of adaptive rood pattern search(ARPS) block-matching algorithm,and according to the correlation between various images in wavelet domain,an hierarchical block-matching algorithm-improved adaptive rood pattern search algorithm based on wavelet transform(WI-ARPS) is proposed.Searching matched-macroblocks in wavelet domain can effectively reduce the number of search points,and the ratio of peak signal to noise of registered images decreases less than 0.ldB compared to the exhaustive-search algorithm.It means that the high registration accuracy is guaranteed.Finally,the projections onto convex sets(POCS) method is used to reconstruct the super-resolution image from the registered images,and it can achieve better visual effects.The simulation results show that the algorithm has a high registration accuracy and reliable reconstruction results.