1. A method for generating a subjective reference model used to estimate the quality of input-video data, the method comprising the steps of: obtaining a plurality of average subjective scores from a plurality of sample video data; calculating a plurality of image metrics for each of the plurality of said average subjective scores; converting at least some of the plurality of said image metrics into corresponding, perceived quality metrics; and, deriving said model based on the plurality of said image metrics and said perceived quality metrics.