Determination of computer-generated hologram universal quantization method for optical image reconstruction

The problem of optical reconstruction of object images using display of quantized computer-generated holograms on a high-speed digital micromirror device is considered. The quantization of light distributions is widely used for information storage, transmission, processing and compression. To determine the most universal hologram quantization method, four iterative, four noniterative quantization methods, and two methods proposed earlier by the authors of this paper and based on noniterative analysis of the intensity distribution histogram, are investigated. The processing (quantization) rate and quality of images optically reconstructed with computer-generated holograms were analyzed for the methods. The holograms were displayed on a digital micromirror device. Object images were reconstructed in laser light. The quality of reconstruction was assessed using quality metrics such as structural similarity index, correlation coefficient and speckle contrast. It was found that the quality of reconstructed images for the histogram methods is higher by 19 % compared to non-iterative methods and by 15 % compared to resource-intensive iterative methods. The rate of hologram quantization by the developed histogram methods is an order of magnitude higher than the rate of iterative methods. Joint accounting of relative intensity and the specifi ed quality metrics is realized by calculation of the target function. The target function of histogram methods exceeds its values of non-iterative and iterative methods by 5 and 2 %, respectively. The obtained results demonstrate the advantages of the histogram methods (high quality of quantization and little time of image processing), in comparison with the other ones for image reconstruction from binary holograms. Thus the histogram quantization methods are recommended for optical reconstruction of volumetric scenes, compression of holographic data, and high-speed modulation of light fi elds.