the present invention relates to a method and system for evaluating the quality of video data without gaining access to the source data . the system is configured to estimate sharpness metrics by detecting edge pixels and enclosing them with 8 × 8 pixel blocks . for each block , the sharpness according to the kurtosis of the dct is computed . the final metric is the average sharpness of the blocks in the edge profile and includes a robust combination of spatial and frequency domain information .