1 Block Truncation Coding Using Pattern Fitting Source: Pattern Recognition, vol.37, 2004, pp Authors: Bibhas Chandra Dhara, Bhabatosh Chanda Speaker: Shu-Fen Chiou( ) Date: 2004/09/08 2 Outline Introduction BTC (Block Truncation Coding) Purposed method Experimental results Conclusions Comments 3 Introduction Since 1970s the block truncation coding (BTC) has been studied a lot. High PSNR but low compression ration. A modified scheme of BTC is proposed to achieve high compression ration and keeping PSNR as high as possible. 4 BTC (1/3) 5 BTC (2/3) 4 block Bit pattern 6 BTC (3/3) (a) Original image (b) Reconstructed image with conventional BTC(PSNR=32.89 and bpp=2) 7 Purposed method n n Pattern fitting Encoding the block Entropy coding and send receive 8 Pattern fitting (1/4) Set of two-level patterns Pattern book 9 Pattern fitting (2/4) 4 block 4 block Pattern fitting (3/4) 11 Pattern fitting (4/4) Output image after pattern fitting 12 Encoding the block (1/2) Considering entropy coding for and 8-bits for A 13 Encoding the block (2/2) 14 Reconstruction 15 Experimental results Original imageReconstructed image 16 Experimental results Original imageReconstructed image 17 Experimental results Conventional BTC (PSNR=32.89 and bpp=2) Purposed method (PSNR=31.59 and bpp=0.64) 18 Experimental results Experimental result of proposed method and others 19 Conclusions Instead of determining bit-pattern for a block, an optimum bit-pattern is selected from a pattern-book. Our method is presented to achieve higher compression ration and keeping PSNR as high as possible. 20 Comments w i ? , Pattern book?