激光反射层析成像技术是一种新型的远距离、高精度成像手段。滤波反投影是反射层析图像重构中采用的基础性算法,而滤波器的性能对重构图像的质量有较大影响。分析四种典型滤波器的时频特性,进行激光对目标探测的仿真实验,接收激光反射回波,用多种滤波器分别对回波数据进行处理后重建图像。与原始图像相比并进行图像质量评价,以分析各种滤波器对成像的影响。研究结果表明,在有Poisson噪声干扰的情况下,接收激光反射回波图像的振荡与滤波器有关,重建滤波器的主瓣高度和旁瓣衰减对重建图像的空间分辨能力产生影响。
Laser reflective tomography is an updated imaging technique for long-distance and high-accuracy detection. Filter back-projection is a fundamental algorithm for computer tomography. The characteristics of the filters have an important influence on the quality of reconstructed images. Amplitude-frequency characteristics of four typical filters were analyzed,and simulation experiments on laser detection were carried on. The images were reconstructed after processing laser echo data by different filters. The quality of reconstructed images was evaluated,and the influences of filters on imaging were analyzed. Research results show that the oscillation in reconstructed image is related to the filter under the interference of Poisson noise. Amplitude of main lobe and attenuation of side lobes of filter's function affect the spatial resolution of reconstructed images.