Modified PSO method for automating transfer function designing
in volume rendering
XIE Li-jun1, WANG Yan-ni2, ZHANG Shuai1
1. School of Aeronautics and Astronautics, Center for Engineering and Scientific Computation, Zhejiang University,
Hangzhou 310027, China; 2. Finance Department, Daxie Development Zone, Ningbo 315812, China
To reduce the complexity of humancomputer interaction in volume rendering, this paper introduces an automated approach for transfer function designing in volume rendering. This approach transfers the abstract evaluation of a transfer function into the explicit evaluation of its rendering image, and then transfers the designing of a transfer function into a multiparameter optimization problem. The image quality is assessed by combining image information entropy, differential entropy, boundary entropy, and humans subjective evaluation. Optimizing process utilizes an improved PSO (Particle Swarm Optimization) method which is strengthened by a genetic algorithm to avoid falling into the local optimum. The results of tests show that this modified PSO algorithm has a better global searching ability and efficiency in the application of volume rendering. The experimental results demonstrate that the proposed approach is able to design highquality transfer functions according to the humans perspective in 12 minutes for common cases．
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