Abstract: Imaging and visualization of heart play an important role in cardiac disease diagnosis and therapy planning. To visualize the segmented cardiac volume datasets, an approach based on Graphics Processing Unit (GPU) acceleration raycasting algorithm was proposed to reconstruct high-quality image. Firstly, the transfer function was designed by using statistical information of the cardiac volume datasets, which was used for increasing opacity of the subtle tissues. Secondly, the sampling step was adaptively adjusted based on the gradient, which was utilized to increase sampling frequency of the borderline tissues. Finally, the improved Blinn-Phong illumination model with multiple lamp-houses was also employed for enhancing the visualization effect. The experimental results show that the proposed method can meet the requirements of real-time rendering and obtain high-quality volume rendering results. Cardiac subtle tissues are rendered clearly such as valves and coronary artery veins.

Key words: three-dimensional visualization, volume rendering, raycasting, Graphics Processing Unit (GPU), heart

摘要： 心脏成像和可视化技术在心脏疾病诊断、治疗规划中发挥着重要作用。针对分割后的心脏体数据集,提出了使用图形处理器(GPU)加速光线投射算法进行高质量三维可视化的新方法。该方法结合心脏体数据统计信息设计传递函数,增大细微组织的不透明度值;基于梯度模自适应地调整采样步长,提高组织边界的采样频率;应用改进的Blinn-Phong多光源光照模型,增强可视化效果。实验结果表明,该方法在实现实时绘制的同时,能够获得高质量的体绘制效果,渲染出清晰的瓣膜和冠状动脉血管等心脏细微组织。

关键词: 三维可视化, 体绘制, 光线投射, 图形处理器, 心脏