A Fast Tri-linear Interpolation Algorithm for Volume Rendering of Medical Images

Objective Tri linear interpolation is a basic operation in volume rendering for medical images and is executed voxel by voxel to gain the value of each resampled point. The optimization of tri linear interpolation is an important approach of improving the speed of volume rendering, in particular, for the realization of volume rendering for medical images in a personal computer. Method According to the distribution of the values of 8 vertexes of each voxel, all voxels are classified into 128 types. A byte value M is used to denote the classified results. Different equation of interpolation is chosen in accordance with the value of M for each voxel when the operations of interpolation are executed, which can reduce the total operations of interpolation remarkably. Furthermore, by changing the threshold, which is used to determine the type of interpolation of voxel, the total operations of interpolation can be adjusted flexibly. Result According to the property of volume data, an effective and flexible tri linear interpolation algorithm was proposed. Conclusion Compared with other fast tri linear interpolation algorithms, the proposed algorithm has an additional advantage which allows the user to adjust the total operations of interpolation by changing the threshold of classified voxel to the accuracy of resulting image, and speeds up the volume rendering.