基于距离选通的激光成像受激光脉冲能量、距离门门控时间的影响,激光图像对比度偏低,在此基础上进行三维成像的重建效果在整体上存在边缘信息、结构信息严重缺失的问题。因此,提出了一种改善思路,即将引导滤波结合双边滤波的方法应用于二维切片的预处理中,在误差范围内改变二维切片的像素信息分布,以获得高质量的三维重建结果。首先,利用引导滤波增强边缘信息,恢复目标内部的结构信息;然后,结合双边滤波弥补在上一步骤中出现的无效点增多的缺陷,稳定图像的均匀度。研究结果表明:采用引导滤波结合双边滤波的二维图像预处理得到的三维重建结果,在保证距离精度的同时,在边缘信息、结构信息的增强,以及图像的均匀度提升等方面具有优势。

Time-slicing images captured by laser-based active range-gated imaging technique are easily affected by the energy of the laser pulse and gate time. Consequently, the contrasts of time-slicing images are poor. Furthermore, the edge information and structural information are seriously lacked in the reconstruction of three-dimensional imaging. Therefore, an image preprocessing method for time-slicing images based on guided filtering combined with bilateral filtering is proposed to overcome this limitation. The proposed method changes the distribution of pixel information of time-slicing images within the error range to obtain high-quality three-dimensional reconstruction results. First, the guided filtering is employed to enhance edge information and recover structural information within the image. Then, the bilateral filtering is employed to compensate for defects introduced in the previous step (i.e., increasing invalid points). As a result, the uniformity of the image is stabilized. Experimental results demonstrate that three-dimensional reconstruction after applying the proposed preprocessing method achieves better performance in enhancing edge information, structural information, and image uniformity without sacrificing distance accuracy.