扫描型IRFPA非均匀微扫描的无边框亚像元热成像处理算法

针对扫描型热成像中垂直方向微扫描帧间位移不再精确为半像素的情况,按照错位方向的不同,分别采用近似回代算法进行图像重构,并对不同错位方向中近似回代引进的误差进行规律分析,提出一种非均匀微扫描情况下的无边框亚像元热成像处理算法.该算法采用邻近像元对边界像元进行近似回代,并根据统计学原理对近似回代过程中引进的误差进行优化,获得与原始图像高度近似的亚像元图像.实验表明,效果明显好于过采样和直接的近似回代,并且算法简单,处理量小,易于实现实时处理.对提高扫描型热成像系统的技术性能指标具有重要意义.

Algorithm of sub-pixel thermal imaging for nonuniform micro-scanning in scanning IRFPA without boundary

For the thermal images obtained with scan, it happens frequently that the interframe micro-displacement in vertical direction is no longer equivalent to accurate half-pixel. An approximating recursive technique, dealing with the dislocation at different direction, is introduced to reconstruct the image with high resolution. By analyzing the error distribution caused by the approximating recursion, a sub-pixel processing algorithm to reduce the error is proposed. The algorithm uses neighboring pixel to approximate the boundary, and the statistical principle is used to minimize the error introduced by the approximation. The obtained sub-pixel image is highly similar to the original image. All the simulation results and experiment data show that the performance of the algorithm proposed in this paper is obviously better than that of over-sampling and approximating recursive reconstruction. The algorithm is simple and effective. A real time processing is easily achieved. The realization of the algorithm has great significance in improving the technological performance of scanning thermal imaging system.