Wavelet transform image compression coding method in the high compression ratio of the reconstructed image quality is often poor. To solve this issue, a coding algorithm based on spectral graph wavelet transform is proposed. In this method, the image is transformed into a graph, the spectral graph wavelet coefficients are obtained by using the spectral graph wavelet transform to decompose the graph, the energy of these coefficients is attenuated with the increase of the scale. Then, the SPECK algorithm is improved according to the characteristics of the spectral graph wavelet coefficients. Finally, the spectral graph wavelet coefficients are quantized, and the quantized coefficients are compressed by the improved SPECK algorithm, and the original image is restored from the sparse coefficients while the amount of image data is compressed. The experimental results show that the coding method is effective for natural image compression, compared with the compression method based on wavelet transform, the PSNR of the reconstructed image is improved and the change is smooth, and has a larger compression ratio at the same time.%针对小波变换图像压缩编码方法在高压缩比下得到的重构图像质量往往较差的问题, 提出了一种基于谱图小波变换的编码方法. 该方法首先将图像转化成图, 利用谱图小波变换分解图得到谱图小波系数, 这些系数的能量随着尺度的增加而衰减, 然后根据谱图小波系数的特性对SPECK算法进行改进, 最后对谱图小波系数进行量化,利用改进的SPECK算法对量化后的系数进行压缩编码, 并在图像数据量压缩的同时从稀疏系数中恢复原始图像.实验结果表明, 该编码方法对自然图像的压缩具有高效性, 相比小波变换的压缩方法, 重建图像的PSNR有所提高且变化平稳, 与此同时还得到更大的压缩比.
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