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A referenceless PSNR estimator of compressed JPEG images

The paper develops a universal procedure to estimate the level of distortions caused by the JPEG compression of an image of any structural content. To determine the quality, we use the PSNR metric. The procedure allows us to employ different stochastic models to predict the variance of the DCT coefficient quantization noise. A new model for the DCT coefficient distribution is proposed, namely, the double gamma distribution. Experiments show that this model serves well both images rich in detail and those that possess essential regions of monotonicity. Finally, under the hypothesis on the double gamma distribution validity, the paper develops a referenceless PSNR estimator of compressed JPEG images.