激光雷达能同时成距离像和强度像,较其他的成像体制给出更多的有用信息。距离像的去噪是激光雷达图像处理的关键步骤,去噪的好坏直接关系激光雷达在跟踪、定位等方面的精确性。根据距离像噪声来源,采用结合强度像的多级中值滤波对实际的雷达图像进行了去噪处理。首先利用强度像3×3邻域均值和图像平均值消除失落信息影响,然后采用多级中值滤波消除逸出值。分别给出了各步处理结果,最终获得了较清晰的距离像。研究结果表明运用结合强度像的多级中值滤波方法能够有效地抑制相干激光雷达距离像的噪声。

Ladar, which can obtain range image and intensity image, may provide much useful information than other imaging system. Range image noise suppression is a key for ladar image processing. The suppression effects influence directly precision in tracking and pointing. According to range image noise, combining intensity image with multilevel median filtering is used for actual ladar image. First, dropout is removed according to intensity image mean in 3×3 window and whole image mean. Then, outlier is removed by using multilevel median filter. Each processing result is presented and better range image is obtained. The investigation results show that this algorithm can suppress range image noise in coherent ladar effectively.