A no-reference video quality assessment method for VoIP applications

An objective no-reference video quality assessment method is proposed to evaluate the video quality in voice over Internet protocol (VoIP) applications under network distortion. In order to assess the distortions of videos in VoIP applications caused by codec and packet loss, the method evaluates the quality of received videos by calculating the block artifacts and blurring. Video blocking artifacts are measured by splitting the picture into small blocks and calculating the difference of the pixels around each border while video blurring is measured by getting edge information through Sobel operator, and counting the gradient histogram. The weighted sum of block artifacts scores and blurring scores can be calculated using linear regression. In order to eliminate the impact of different video contents, the scores which represent the quality of videos need to be normalized. The experimental results show that the objective quality scores have a strong correlation with the subjective quality scores, and the algorithm can be used in video quality assessment in VoIP applications.