摘要： 经过离散余弦变换的图像在DCT域系数的分布近似符合一个用参数λ描述的拉普拉斯分布。利用该参数以及图像在JPEG压缩中使用的DCT域量化系数，可以实现对图像量化噪声的估计。提出一种基于图像先验知识的分布参数估计方法，可以在没有未压缩的原始图像作为参考时实现对λ值的估计，进而计算压缩图像的峰值信噪比。

关键词: 拉普拉斯分布, 压缩图像, 量化噪声, 峰值信噪比

Abstract: The distribution of coefficients of image in the DCT domain can be modeled by a Laplace probability density function with parameter λ. Quantization noise of a compressed image can be estimated from its quantization parameter and λ. This paper proposes a method to estimate the distribution parameter λ and Peak Signal to Noise Ratio(PSNR) according to trained image blocks in spatial domain. As no original image is required, this method is actually no-reference PSNR estimation.

Key words: Laplace distribution, compressed image, quantization noise, Peak Signal to Noise Ratio(PSNR)

中图分类号: 

• TP301.6