A method of estimating coding PSNR using quantized DCT coefficients

A new method of estimating coding peak signal-to-noise ratio (PSNR) without the use of reference signals is presented. Although PSNR is commonly used as a measure of the picture degradation of digitally coded video, the calculation requires source signals as a reference.Therefore, the usage of PSNR is restricted to particular applications or systems. The proposed method enables PSNR estimation based on the probability density functions of quantized discrete cosine transform (DCT) coefficients extracted from an MPEG-2 bit stream. We experimented with MPEG-2 video coding bit streams under varying quantization scheme and evaluate a new method with comparing estimated PSNRs with actual PSNRs. Experimental results indicate that the determination coefficients are higher than 0.9 This method can apply to both SDTV and HDTV, and can evaluate PSNR of every frame coded by different picture types.