无源毫米波成像改进POCS超分辨率算法

摘要

The problem of poor resolution of acquired image in the passive millimeter wave imaging stems mainly from antenna size limitations. Thus efficient post-processing is necessary to achieve resolution improvements. The algorithm combines the advantages of Wiener filter restoration algorithm and POCS algorithm based on convex set theoretic. The Wiener filter is employed to restore the pass-band spectrum, and the POCS algorithm is applied to complete spectral extrapolation as the main iterative process to ensure that low-frequency component is not destroyed as spectral extrapolating. Experimental results demonstrate the algorithm improves the convergent rate and is computationally much more efficient than POCS algorithm. The algorithm is easily implemented in real time for passive millimeter wave imaging.%在无源毫米波成像中,因为受天线孔径大小的限制而导致获取的图像分辨率低,所以必须采取有效后处理措施增强分辨率.提出了一种改进的POCS超分辨率算法,该算法结合了Wiener滤波器复原算法和凸集投影(POCS)算法的优点,使用Wiener滤波复原算法恢复图像通带内的低频分量,运用POCS算法作为主迭代过程实现频谱外推,同时保证低频分量不被破坏.实验结果表明,该算法增强了图像的分辨率,改善了收敛速度,减少了计算量,有利于无源毫米波成像超分辨率的实时实现.