改进的块截断图象编码算法

Modified Block Truncation Coding of Images

已经提出的各种块截断算法本质上都是两电平量化器，由于它们将图象简单地量化（或截断）成两个电平值，所以在译码图象中出现块失真．为减少这种失真，本文在块截断算法中采用了平滑滤波器，从而改进了现有块截断算法的性能，明显提高了译码图象质量．

Various block truncation coding (BTC) algorithms proposed till now are in factthe two level quantizers. They quantize each image block into two levels,which result in obviousblocking effect especially in edges in the decoded images. In order to reduce the blocking distortion,we adopt a smooth filter for BTC and obtain modified block truncation coding(MBTC) algorithms. The experimental results show that MBTC can achieve the better image quality than otherBTC schemes,and decrease the blocking disortion.