An enhanced method for generation of binary Fresnel hologram based on adaptive and uniform grid-cross down-sampling

It has been revealed in past research that by uniformly down-sampling the object image prior to the numerical generation, and subsequent binarization of its digital Fresnel hologram, the reconstructed image can preserve the shaded content with favorable visual quality. However, the down-sampling process also severs the lines and blurs the edge patterns that are important in representing the detail information of an image scene. In this paper, we propose a method to overcome this dilemma with an integration of a fast adaptive down-sampling and the uniform down-sampling process. Experimental evaluation has demonstrated that our method is capable of preserving lines and edges, as well as the shaded regions, resulting in superior visual quality of the reconstructed image as compared with the existing approach. In addition, the computation time on the integrated down-sampling method is less than 200ms on a typical personal computer.