An adaptive image bit-depth scaling method for image displays

This paper introduces a new technique for image bit-depth scaling for display devices. Conventional bit-depth scaling methods such as spatial 2D filtering and dithering algorithms suffer from false contours or dithered pattern artifacts, which significantly deteriorate image quality in display devices. In this paper, we propose a spatiotemporal 3D adaptive noise shaping filter whose coefficients are varied according to the characteristics of the input video signal. This filter minimizes the quantization error by adaptively altering the spectral shape of the error such that it does not produce visual annoyance in the reduced bit-resolution images. Experimental result shows that the proposed method effectively reduces the false contouring and dithered pattern artifacts compared with the conventional and current methods.