Parallel Numerical Simulation of Visual Neurons for Analysis of Optical Illusion

Detailed mechanism of optical illusion caused by visual neurons in human brain has not been well understood, and its numerical simulation is helpful to analyze visual system of humans. This paper describes implementation techniques of parallel numerical simulation to help understanding optical illusion by using a GPU-accelerated PC cluster. Our parallel acceleration techniques include following three points. Firstly, input images of the numerical simulation is efficiently calculated by dividing it images for multiple computation nodes using MPI (Message Passing Interface). Secondly, convolution, which is dominated computation for the optical flow, is accelerated by GPU. Finally, an algorithm to compute convolution specified to analyze optical illusion is proposed to speed up the simulation. Our experimental results show an interesting insight that values of optical flow for images causing optical illusion are quite different compared to that does not cause the optical illusion. We also demonstrate that our implementation of simulation works efficiently on the GPU-accelerated PC cluster.