基于贝塞尔曲面的投影图像几何优化方法  

Geometric optimization of projection image based on Bezier surface

作　　者：宋涛[1,2,3] 祁继辉 侯培国 李坤[2] 赵明宇 SONG Tao;QI Jihui;HOU Peiguo;LI Kun;ZHAO Mingyu(School of Electrical Engineering,Yanshan University,Qinhuangdao,Hebei 066004,China;Qinhuangdao Audio Visual Machinery Research Institute,Qinhuangdao,Hebei 066004,China;Hebei Key Laboratory of Digital Imaging Equipment and Digital Display Technology,Qinhuangdao,Hebei 066004,China)

机构地区：[1]燕山大学电气工程学院,河北秦皇岛066004 [2]秦皇岛视听机械研究所,河北秦皇岛066004 [3]河北省数字影像装备与数字显示技术重点实验室,河北秦皇岛066004

出　　处：《燕山大学学报》2021年第5期449-455,共7页Journal of Yanshan University

基　　金：国家自然科学基金资助项目(62033011);河北省技术创新引导计划科技冬奥专项资助项目(19975707D)。

摘　　要：针对多通道投影洞穴状自动虚拟系统几何校正精度不高的问题,提出一套基于分段贝塞尔曲面的几何优化来保证同一通道投影图像的异面投影几何校正精度。首先通过同一投影画面理想区域的投影平面分布对投影图像进行矩阵分块,再根据投影图像每个分块矩阵在对应理想投影平面的像素分布情况进行透视变换以此保证每个通道投影画面的整体分布,然后通过摄像机把屏幕空间转换至摄像空间识别棋盘格投影画面内角点坐标以此判断其平均绝对误差,最后根据同一投影画面的不同投影平面区域分布采用分段贝塞尔曲面对其进行几何优化,直到平均绝对误差低于标准值为止。实验表明,非均匀分段贝塞尔曲面几何优化使摄像空间内的角点横纵坐标平均绝对误差分别降低了1.13像素和0.93像素。因此,非均匀分段贝塞尔曲面几何优化方法只需少量控制点便可对异面投影进行准确校正且平均绝对误差相对降低。Aiming at the problem of low accuracy of geometric correction in multichannel projection cave automatic virtual environment system,a set of geometric optimization based on segmented Bezier surface is proposed to ensure the accuracy of geometric correction for different plane projections in the same channel.Firstly,the projection image is divided into matrix blocks by the projection plane distribution of the ideal region of the same projection image.Secondly,according to the pixel distribution of each block matrix in the corresponding ideal projection plane,the perspective transformation is carried out to ensure the overall distribution of each channel projection image.Thirdly,the average absolute error can be determined by the camera converting the screen space to the camera space to identify the internal corner coordinates of the chessboard projection picture.Finally,according to the different projection plane area distribution of the same projection picture,segment Bezier curve is used to optimize its geometry until the average absolute error is lower than the standard value.The experimental results show that the average absolute errors of the horizontal and vertical coordinates of the corners in the camera space are reduced by 1.13 pixel and 0.93 pixel respectively.Therefore,the non-uniform segmented Bezier surface geometric correction method only needs a few control points to correct the different plane projection accurately and the average absolute error is relatively reduced.

关 键 词：多通道投影系统 摄像机 几何校正 透视变换 贝塞尔曲面 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]