基于自适应小波变换和矢量量化的图像压缩编码

运用小波变换进行图像压缩的算法其核心都是小波变换的多分辨率分析以及对不同尺度的小波系数的量化和编码 .本文提出了一种基于能量的自适应小波变换和矢量量化相结合的压缩算法 .即在一定的能量准则下 ,根据子图像的能量大小决定是否进行小波分解 ,然后给出恰当的小波系数量化 .在量化过程中 ,采用一种改进的LBG算法进行码书的训练 .实验表明 ,本算法广泛适用于不同特征的数字图像 ,在取得较高峰值信噪比的同时可以获得较高的重建图像质量 .

The Image Compression Based on Adaptive Wavelet Transform and Quantization

Image compression based on wavelet transform,which gives emphasis to multi-resolution analysis and quantization and coding of the different scaling wavelet coefficients,this paper puts forward a compression algorithm based on vector quantization and adaptive wavelet transform based on energy.That sub-images are whehter to be compressed or not is decided by their energy that is defined by certain criterion.Then the quantization and coding of some wavelet coefficients is given.In the procedure of quantization,this paper makes use of an improved LBG algorithm to generate codedbook.Through experiments,not only the algorithm of this paper can adapt to various images,but also the quality of recovering image is improved though PSNR is higher.