Fast calculation method of a CGH for a patch model using a point-based method.

Holography is three-dimensional display technology. Computer-generated holograms (CGHs) are created by simulating light propagation on a computer, and they are able to display a virtual object. There are mainly two types of calculation methods of CGHs, a point-based method and the fast Fourier-transform (FFT)-based method. The FFT-based method is based on a patch model, and it is suited to accelerating the calculations as it calculates the light propagation across a patch as a whole. The calculations with the point-based method are characterized by a high degree of parallelism, and it is suited to accelerating graphics processing units (GPUs). The point-based method is not suitable for calculation with the patch model. This paper proposes a fast calculation algorithm for a patch model with the point-based method. The proposed method calculates the line on a patch as a whole regardless of the number of points on the line. When the proposed method is implemented on a GPU, the calculation time of the proposed method is shorter than with the point-based method.