基于视差放大与超分辨率的三维光场腹腔镜标定  

Three-dimensional light field endoscope calibration based on light field disparity amplifier and super-resolution network

作　　者：刘雪岩 许聿达 雷建昕 周光泉[1] 张为中[2] 周平[1] LIU Xueyan;XU Yuda;LEI Jianxin;ZHOU Guangquan;ZHANG Weizhong;ZHOU Ping(School of Biological Science&Medical Engineering,Southeast University,Nanjing 210016,China;The First Affiliated Hospital of Nanjing Medical University,Nanjing 210029,China)

机构地区：[1]东南大学生物科学与医学工程学院,江苏南京210016 [2]南京医科大学第一附属医院,江苏南京210029

出　　处：《光学精密工程》2022年第5期510-517,共8页Optics and Precision Engineering

基　　金：国家自然科学基金面上项目(No.52071075)。

摘　　要：基于光场成像理论的三维腹腔镜是实现腹腔三维成像的重要研究方向,标定是光场腹腔镜实现三维成像的基础。针对光场带宽积与较小的光场视差会制约三维光场腹腔镜标定精度提升的问题,提出了一种视差放大方法,将直接计算光场视差的问题转换为间接计算两个特征点的距离问题,较大的特征点间距在光场图像中体现为易于检测的点-点间距和点-线间距,从根本上提高了光场腹腔镜的标定精度;基于SRDenseNet的改进型超分辨率网络,整合通道注意力机制,同时提高了光场腹腔镜四维成像的角度分辨率与位置分辨率,间接地提高了光场腹腔镜的标定精度。实验结果表明,经光场视差放大与超分辨处理后,三维光场腹腔镜标定的反投影误差降低了16%,R2提高了6%。Three-dimensional(3D)light field imaging in laparoscopic surgery is an emerging technology,which has the potential to enable 3D imaging.Calibration is fundamental for the 3D light field endoscope(LFE)to accomplish 3D imaging and is essential but challenging as the light field bandwidth product is limited;moreover,the light field disparity of a 3D LFE is smaller than that of the conventional light field camera,which makes it difficult to achieve acceptable light field calibration results.In this paper,the small light field disparity was amplified by computing the distance between two feature points in a 3D scene.Compared with the conventional light field disparity between different feature points in different subaperture images,the distance between the two feature points enlarges the distance,i.e.,the disparity between point-to-point and point-to-line,in the light field image,which leads to better calibration accuracy.Furthermore,an improved super-resolution network based on SRDenseNet was proposed,where cascaded channel attention dense blocks were applied to acquire the features of low-resolution light field images.The super-resolution network improved the two-dimensional(2D)spatial resolution and 2D angular resolution in the 4D light field data simultaneously and improved 3D LFE calibration accuracy indirectly.The experimental results show that the amplified light field disparity and higher resolution facilitated a higher calibration performance,and the reprojection error of the 3D LFE calibration decreased by 16%,while the Rsquare increased by 6%.

关 键 词：医学成像 光场腹腔镜 光场视差 超分辨率 标定 

分 类 号：R318.6[医药卫生—生物医学工程]