Methods for objective measurement of video quality

In this paper, we propose a new method for objective measurement of video quality using the wavelet transform. We first note that the sensitivity of the human visual system varies in spatio-temporal frequencies. This characteristic of the human visual system is exploited to develop a method for objective measurement of video quality. First, in order to compute spatial frequency components, the wavelet transform is applied to each frame of video. Then, the difference (squared error) of the wavelet coefficients in each subband is computed and summed up, producing a difference vector for each frame. By applying this procedure to the entire frames of a video, we will obtain a sequence of difference vectors and the average vector is computed. Each component of this average vector represents a difference in a certain spatial frequency. In order to take into account the temporal frequencies, we propose a modified 3-D wavelet transform. In either case, a single vector represents the difference between the source and the processed videos. From this vector, a number is computed as a weighted sum of the elements of the vector and that number will be used as an objective score. Experimental results show that the proposed method compares favorably with the existing methods.