基于改进预积分技术的光线投射三维重建算法  

Ray casting algorithm for three-dimensional reconstruction based on improved pre-integration technology

作　　者：王亚晨 王瑜[1] 宫宁 肖洪兵[1] WANG Yachen;WANG Yu;GONG Ning;XIAO Hongbing(School of Artificial Intelligence,Beijing Technology and Business University,Beijing 100048,China)

机构地区：[1]北京工商大学人工智能学院,北京100048

出　　处：《中国医学物理学杂志》2024年第9期1133-1138,共6页Chinese Journal of Medical Physics

基　　金：北京市自然科学基金-北京市教育委员会科技计划重点项目(KZ202110011015);2023年北京工商大学研究生科研能力提升计划项目。

摘　　要：在传统的光线投射算法中,由于传递函数具有非线性,导致奈奎斯特采样定律常常无法被满足,影响生成模型的质量,因此,本研究提出一种基于改进预积分技术的光线投射算法。首先在传统光线投射算法中引入预积分分类技术,利用其面对任何非线性传递函数都可以规避最大奈奎斯特采样频率的优势提升三维重建模型的质量;然后利用设计的预积分加速算子,优化不透明度与颜色值的计算方法,简化预积分合成流程,缩短三维模型重建的时间。实验结果显示,利用本文算法对人工合成的三维圆锥进行重建,速度可提升22.5%,对真实的冠脉计算机断层扫描图像进行重建,绘制速度可提升23.8%,并且生成三维圆锥图像的均方误差值小于传统光线投射算法,结构相似度值大于传统光线投射算法,证明本文算法既可以提高重建模型的质量,也可以提升重建速度。Due to the nonlinearity of the transfer function in the traditional ray casting algorithm,Nyquist sampling theorem often can't be satisfied,which affects the quality of the generated model.Therefore,a novel ray casting algorithm is proposed for three-dimensional(3D)reconstruction based on improved pre-integration technology.The pre-integration classification technology is introduced into the traditional ray casting algorithm to improve the quality of the reconstructed 3D model by avoiding the maximum Nyquist sampling frequency for any nonlinear transfer function.Then,the pre-integration acceleration operator is used to optimize the calculation methods for opaqueness and color value,thus simplifying the preintegration synthesis process and shortening the time for 3D model reconstruction.The proposed algorithm speeds up the reconstructions for the synthetic 3D cone and real coronary artery CT image by 22.5%and 23.8%,and additionally decreases mean square error of the generated 3D cone images,while increasing structural similarity index as compared with the traditional ray casting algorithm,which demonstrates that the proposed algorithm can improve both the reconstructed model quality and the reconstruction speed.

关 键 词：图像重建 光线投射算法 预积分技术 

分 类 号：R318[医药卫生—生物医学工程] TP317.4[医药卫生—基础医学]