摘要
设计了一种基于图像块细粒度的自适应单像素成像算法。首先获取目标的低分辨图像,将其分为四等块,根据每块中重要小波系数的个数与分布,将其分为非重要、重要和半重要三类。非重要块不采样;重要块全采样;半重要块进行迭代分块、分类,部分采样。利用小波反变换重建高分辨图并重复上述步骤,直到重建图像达到目标分辨率。实验结果表明,对于背景平滑的医学生物图像,本文方法能够在相同采样率下至少提高重建图像PSNR约2 dB。
Images were divided into four equal-sized blocks by adaptive compressive imaging.The four blocks were classified into two types after getting the number of important discrete wavelet transform(DWT) coefficients,which are the important blocks and the unimportant blocks.The important blocks were all sampled with higher resolution,leading to high sampling rate.To solve these problems,an imaging method is designed based on fine precision classification of image blocks.Coarse image is reconstruted and divided into four equal-size blocks first.Then the four image blocks are classified into three types according to the number and distribution of their important DWT coefficients,which are the unimportant blocks,the important blocks and the partly important blocks.The unimportant blocks are ignored.The important blocks are all sampled with higher resolution.The partly important blocks are divided repeatedly,and only the important parts are sampled.Image with higher resolution is reconstructed through inverse wavelet transform.Steps above are repeated until the reconstructed image gets required resolution.Experimental results show that compared with other three algorithms,the peak signal-to-noise ratio(PSNR) of reconstructed images is improved by at least 2 dB with similar sampling rate for biology images.
引文
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