Rapid Pre-Integrated Perspective Volume Rendering Algorithm of Medical Data Sets

Perspective volume rendering has well known advantages in medical visualization application. In the visualization of 3D medical images, it is common to adjust frequently the Opacity Transfer Function(OTF) and viewing angle so that volume rendering is difficult to be realized in real-time. And in traditional perspective Shear-Warp there are the aliasing and staircase effects resulting from under-sampling. In order to efficiently and effectively reconstruct 3D medical images, a novel Rapid Pre-Integrated Perspective Volume Rendering(RPPVR) method of medical data sets based on Pre-integrated volume rendering and Shear-Warp algorithm is proposed in this paper. In the proposed method, classification coding for volume data is implemented by making use of the correlation of opacity transfer function and min-max Octree data structure. On this basis, the new run-length encoded(RLE) data structure can be established rapidly so that fast reconstruction can be done when opacity transfer function and view angle change. Moreover, the aliasing artifacts resulted from under-sampling can be eliminated by pre-integrated volume rendering technique incorporated the shading calculation of Phong lighting model, thus improving the reconstruction effect. This study demonstrates the superiority of the proposed method.