基于平坦度的激光雷达强度图像的滤波算法

激光雷达是一种比较新的获取地面信息的方法，这种方法得到的数据不仅包括不规则间距的三维数据点云，还包括激光强度信息。现有的激光雷达数据处理方法大都是将三维数据点进行处理得到数字地面模型（DTM），对于激光强度信息的处理方法的研究比较少。针对激光雷达数据中像素级融合了三维信息和强度信息的特点，提出了一种基于高程信息平坦度的均值滤波算法。先将激光雷达的强度信息转换为灰度图像，然后在对各像素进行均值滤波处理时，融合了对应的激光雷达距离信息中该像素邻域内的高程信息。运用此算法和传统均值算法对激光雷达数据进行了处理，并且使用多种指标对处理结果进行了比较。结果表明，该算法既保持了传统均值滤波的优点，又改进了对弱边缘目标的保护。

A Kind of Filter Algorithms for Lidar Intensity Image Based on Evenness Terrain

Lidar (light detection and ranging) is a relatively new method for the acquisition of terrain surface. The lidar system not only generates the 3-dimensional cloud of points with irregular spacing, but also gets the laser impulse reflection data. Algorithms and software used for the lidar data are used to deal with the 3-dimensional cloud of points, and get the digital terrain model (DTM). Algorithms applied in the laser impulse reflection data are little. According to the character of lidar data, which fused the 3-dimension information and intensity information in pixel-level, a new fusion filtering algorithm based on the flatness of terrain is proposed in this paper. The algorithm translates the intensity information of lidar data into intensity image, and then uses a new fusion mean filter which fused the elevation information of each pixel′s neighborhood, to deal with the intensity image. The algorithm and mean filtering algorithm are applied in lidar data, and their results are compared in different evaluation parameters. The result shows that the proposed algorithm has some improvement in keeping the advantage of mean filtering algorithm under the condition of preserving unclear edges of the image.