Fast block prediction-based coding of compound images by exploiting edge orientation
S. Ebenezer Juliet, V.R. Sadasivam, D. Jemi Florinabel · International Journal of Signal and Imaging Systems Engineering · 2013
Compound images are a combination of text, graphics and natural images. This paper presents a new fast block prediction algorithm for coding of text/graphics parts which exploits the direction of edges in the text/graphics blocks. The proposed scheme classifies the text/graphics blocks into four kinds of blocks using edge characteristics of transformed coefficients of blocks. This edge–based block classification improves the speed of intra–block prediction mode decisions significantly. Experimental results show that the proposed method improves the value of PSNR more significantly than standard JPEG, JPEG–2000 and H.264/AVC–I, while keeping competitive compression ratio and visually lossless quality of text information.