基于投影纹理映射的球面斜投影校正方法研究及其应用  

Research of Spherical Inclined Projection Correction Method Based on Projective Texture Mapping and its Application

作　　者：邱飞岳[1,2] 赵柏乐[2] 张维泽[1] 王丽萍[3] 

机构地区：[1]浙江工业大学现代教育技术研究所,杭州310014 [2]浙江工业大学信息工程学院,杭州310023 [3]浙江工业大学智能信息处理研究所,杭州310023

出　　处：《中国生物医学工程学报》2012年第5期697-703,共7页Chinese Journal of Biomedical Engineering

基　　金：国家科技型中小企业技术创新基金(11C26213304686);浙江省自然科学基金(R2080100);浙江省科技计划项目(2011C21013)

摘　　要：临床上采用平面显示屏幕的视功能诊疗设备,因视场角过小,无法模拟自然视觉环境,影响视功能的诊疗效果。本研究自主研发一种半球投射式的显示装置,对球面屏幕和斜投影所导致的几何失真问题,提出了一种基于投影纹理映射的球面斜投影校正方法,投射后的图像畸变小、效果好,接近自然视觉环境,改善视功能的诊疗效果。该方法假设人眼和投影仪满足针孔模型,根据投影系统的几何参数,利用OpenGL构建投影系统的计算机三维模型,将观察者视为投影仪设置投影矩阵,并将被投影图像映射到屏幕上,然后将投影仪视为观察者设置模型视图矩阵获得所需的预变形图像。该预变形图像由诊疗环境中的投影系统所使用,实现图像的几何校正。实验结果表明:该方法校正后的图像失真较小,矩形度为0.985 7;对640像素×400像素的图像平均处理时间约为0.031 s,能够较好地符合临床上视功能诊疗要求。At present, the vision examination and treatment equipment using flat-panel display screen does not meet the requirement of virtual reality in vision clinic environment which influences the clinical results of visual function. Based on the independent research and development of a hemispheric-projection display device that introduces the geometric distortion caused by the spherical screen and inclined projection, this paper presented a spherical inclined projection correction method based on projective texture mapping in order to let the observer have a realistic view of images with no/little distortion, thereby improving visual function examination and treatment environment. With the assumption that human eyes and projectors meet pinhole model, the method builds three-dimensional computer model of the projection system with OpenGL according to its geometric parameters, maps the projected image （as a texture） to the screen through setting the projection matrix by regarding the observer as a projector, and obtains the pre-distorted image through setting model view matrix by regarding the projector as an observer. Finally, the pre-distorted image was applied in the projection system of the vision examination and treatment equipment for geometric correction. The experimental results showed that the distortion was small with the rectangular degrees of 0. 985 7, the process was almost real-time （the average handling time for an image of 640 pixel × 400 pixel was about O. 031 s）, which meet the requirements of immersion in visual function examination and treatment.

关 键 词：视功能 投影纹理映射 球面斜投影 OPENGL 几何校正 

分 类 号：R318.08[医药卫生—生物医学工程]