一种环状编码标记点的设计及解码算法

针对近景摄影测量中对编码标志点的精确定位和准确识别的要求，提出一种环状编码标记点的设计和识别算法。在传统环状编码标记点的基础上添加3个定位符，用于确定标志点的精确位置和增加标志点的数量。解码时先检测定位符坐标及其在标志点中的位置，然后对编码标志点进行透视变换以实现图像校正的目的，最后用提出的基于圆环扫描的方法进行解码。实验结果表明，该算法对任意旋转角度下的编码标志点均能有较好的检测识别效果；当摄像机与标记平面的夹角小于65°时，其识别准确率可达99.3%；在复杂背景情况下的平均识别准确率为97.4%，误识别率为1.25%，识别平均速率为2.15 s/幅。

Designing and decoding algorithm of circular coded target

On the requests of coded targets in close range photogrammetry for precision location and accurate recognition, proposed a designing and decoding algorithm of circular coded target. This paper added three locators on the basis of traditional circular coded target to achieve precision position and increase the number of targets. Firstly, the algorithm detected the locator coordinates and their positions in the targets. Then, the perspective transformation of the coded target was used to achieve image distortion correction. Finally, used the method based on the ring scan to achieve the decoding of the circular coded target. Experimental results show that the algorithm in this paper can have good detection and recognition results for all the coded targets which rotate any angle; when the angle between the camera and the marking plane is less than 65°, the recognition accuracy rate can reach 99.4%; the average recognition accuracy rate is 97.4%, false recognition rate is 1.25%, recognition rate is 2.15 seconds under the complex background.