An adaptive enhancement algorithm for quantized images

Abstract When high-quality images are displayed by low-level graphics devices, they must be re-quantized. Many quantization algorithms have been proposed to solve this problem. However, the fine details cannot manifest themselves in the quantized images by the general quantization algorithms. In this paper, an adaptive technique is proposed to enhance the quantized images such that the fine features such as edges, thin lines, and curves are more visible. By tuning a threshold value, the desired patterns used to produce the visual impression of grayscale information at constant and small varying areas can be preserved and the high frequency information can made more visible.