一种基于小波-Contourlet变换的图像编码算法

Image Coding Using Wavelet-Based Contourlet Transform

根据小波-Contourlet变换对图像分解具有多尺度和多方向性的特点,提出了一种结合小波-Contourlet变换和集合分裂嵌入块(SPECK)编码的图像压缩算法(CSPECK)。小波-Contourlet通过方向滤波器组把小波分解的高频子带进一步分解为多个方向子带,从而可更稀疏地表示图像的边缘和纹理。SPECK算法编码具有复杂度低和编码效率高的优点。实验结果表明,CSPECK算法对纹理丰富的图像有很好的压缩效果,与基于小波-Contourlet变换的CSPIHT算法相比,峰值信噪比提高了0.2～0.6dB。

As the wavelet-based contourlet transform provides a multi-scale and directional decomposition for images, a new image coding scheme called CSPECK was proposed, which was constructed by wavelet-based contourlet transform and wavelet-based contourlet transform, th form was further decomposed into mult set partitioning embedded block （SPECK） algorithm. In the e high frequency sub-band decomposed by the wavelet trans- iple directional sub-bands by directional filter bank so as to explain the edge and texture of the image more sparsely. The SPECK algorithm exhibits lower complexity and more efficient compression ratio. Experimental results demonstrate that the proposed method is efficient in coding images that possess mostly textures and contours. The simulation results also show that this new coding algorithm increases the PSNR by 0.2- 0.6 dB over CSPIHT.