基于线段检测算法的倾斜摄影直角像控点目标检测方法

针对航空摄影测量中空三加密时数据内业精校正的人工刺点效率低下,误差较大等问题,本文提出了一种基于线段检测(Line Segment Detector,LSD)算法的直角像控点目标检测方法.该方法首先通过Retinex算法增强影像彩色信息;再对影像进行双边滤波,在去除噪声的同时能很好的保留边缘信息;然后使用LSD算法提取...

Detection of Tilted Aerial Photography Right-Angled Image Control Points Target based on LSD Algorithm

Aiming at the problems of low accuracy and large error in artificial prick points during the internal work’s precise correction of the aerial triangulation data during aerial photogrammetry, we propose a method in this paper for detecting the right-angled edge control points based on the LSD algorithm. First, the image is bilateral filtered to remove noise while preserving edge information and image color information enhanced by Retinex algorithm. Then, the right-angled edges of the image control point are extracted by LSD line detection, and the outermost right-angled edge is filtered by the angle, distance, and length information. Finally, the right-angled image control points are obtained through the intersection. We tested our method using 80 images of "L" image control points and 69 images of "X" image control points taken by Dajiang UAV. Results show that this method can get accurate pixel coordinates of image control points, and maintain a high accuracy in cases with complex background and target distortion. The overall image control point extraction accuracy rate was 93.75%, and the image control point positioning accuracy reached 2.3 pixels, which significantly overcame the artificial puncture points. Compared with Radon and PPHT algorithms, the accuracy of the image control point group detection is significantly improved in our results, which indicates a higher detection accuracy with less influence from the shooting angle.