针对小波变换图像压缩存在的边缘模糊问题,提出了边缘检测与压缩编码相结合的方案,首先利用小波变换的多尺度特性提取图像边缘,将其在高频子带内对应的小波系数乘上一个加权因子,然后利用本文提出的无表SPIHT算法进行编码。本文方案结构简单,无需链表,易于硬件实现,而且有效地克服了G ibbs效应,提高了恢复图像质量。

At low bit rate,images reconstructed from wavelet transform-based algorithms have blurred edges,which is called Gibbs effect.This effect hampers the recognition of objects in the image.This paper presents a new progressive image coder which employs edge detection to improve the visual appearance and possibility of recognizing the compressed images at very low bit rates.Edge information is enhanced before compression coding considering some certain weighting factors.Experimental results show that the new algorithm can yield highly recognizable images at very low bit rates.