Block classification-based compression method for computer screen image
Weikang Gu · Journal of Zhejiang University(Engineering Science) · 2009
A block-based compression method for computer screen image was proposed to realize real-time computer screen image transmission.Each block of image was classified into three categories: text/graphic block,hybrid block and picture block according to the different characters on color and texture.Text/graphic block was compressed with a lossless coding algorithm integrating palette coding,Hextile coding and LZW algorithm.Picture block was compressed with lossy JPEG.Both lossless and lossy methods were used on hybrid block.Experimental results showed that the method exactly distinguished between the text/graphics and the picture information.The peak signal-to-noise ratio(PSNR) of the reconstructed image was improved 1~4 dB compared with other methods.The method achieved good compression ratio with low computation,which satisfied the real-time requirement.