基于提升方案的整数小波图像编码

Integer Wavelet Image Coding Via Lifting Scheme

随着互联网的普及和图像应用范围的不断扩大,对图像的编码提出了新的要求,即不仅要求具有高的压缩比,还要求有许多新的功能,如渐进编解码、从有损压缩到无损压缩等。小波编码较好地实现了这一思想,因此奠定了它在图像编码中的地位。提升框架可以实现整数到整数的小波变换,克服了第一代小波变换所带来的缺陷。该文利用第二代小波变换的特性,提出了一种基于整数小波变换的图像压缩方法。首先充分利用小波系数的分布特性,将图像进行整数小波变换,然后对最低频子带采用DPCM预测编码,对其它子带采用零树加熵编码的方法进行编码。实验结果表明,该方法有较好的压缩性能。

With the extensive application of internet and image,some new requirements on image coding,such as high compression rate ,pregressive codec,and compression from lossy to lossless, are to be satisfied.These functions can be performed well by wavelet coding.The lifting scheme can realize integer-integer wavelet transform, that can overcome the limitation caused by the first generation wavelet transform. Author carry through wavelet transform on given image based on integer wavelet firstly, then use different coding methods on different subbands to use the distributing character of wavlet coefficients. The experimental results show that the method is a simple and practical algorithm.