摄影测量中环状编码标靶识别与定位方法  

Ring-coded target identification and localization method in photogrammetry

作　　者：李恒 杨延竹[1] 柳俊先 杨肖 LI Heng;YANG Yanzhu;LIU Junxian;YANG Xiao(College of Mechanical Engineering,Donghua University,Shanghai 201620,China)

机构地区：[1]东华大学机械工程学院,上海201620

出　　处：《东华大学学报（自然科学版）》2024年第1期77-84,共8页Journal of Donghua University(Natural Science)

摘　　要：为满足环状编码标靶精准定位与识别的要求,提出了一套定位精度和识别稳定性较高的算法。针对环状编码标靶的精确定位,提出了一种基于同心圆投影变换求解圆心的方法;在对编码标靶进行识别时,通过仿射变换将椭圆变为标准圆,进而对内部编码带进行解码得到其唯一解码值。试验结果表明:该圆心提取方法与理想圆心平均误差为0.225像素,与椭圆拟合提取外圆圆心平均误差为0.501像素,与内圆圆心平均误差为0.294像素,其精度分别提高了122.05%与30.26%;相机与编码标靶夹角需控制在75°以内,夹角小于75°时,编码标靶识别率可达100%。研究表明该编码标靶识别与定位方法能够满足摄影测量需求,且比椭圆拟合算法精度更高,具有一定的实际意义。A set of algorithms with high positioning accuracy and recognition stability is proposed to meet the requirements of accurate positioning and recognition of annular coded ring-code targets.A method based on concentric projection transformation to solve the circle center is proposed for the precise positioning of annular coded targets.In the recognition of coded targets,the ellipse is changed into a standard circle by affine transformation,and then the internal coded band is decoded to get its unique decoded value.The experimental results show that the average error of the circle center extraction method is 0.225 pixels with the ideal circle center,0.501 pixels with the ellipse fitting to extract the outer circle center,and 0.294 pixels with the inner circle center,and its accuracy is improved by 122.05%and 30.26%respectively.The angle between the camera and the coding target needs to be controlled within 75°,when the angle is less than 75°,the coding target The recognition rate of the coding target can reach 100%when the angle is less than 75°.The study finds that the coded target recognition and positioning method can meet meets the photogrammetry requirements and has practical significance because it is more accurate than the ellipse fitting algorithm.

关 键 词：环状编码标靶 摄影测量 投影变换 射影几何 仿射变换 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]