Analytical overview of metrics used to assess the quality of multimedia information

Data quality is an indicator that characterizes any transmitted information that can be measured. The very word “measure” suggests the evaluation of these data, the quality of which can be described and quantified. The metric, in turn, is essentially an objective assessment during testing, which makes it possible to determine data distortions that occur during transmission, encoding, digitization, compression, and decoding of video data. The article considers such metrics as PSNR and VQM, and analyzes the ITU-R-BT.500-8.11 standard. A brief overview of the MSU Video Quality Measurement Tool is presented, as well as a simulated video conferencing image acquisition using one of the most popular H264 codecs. The formulas for calculating the PSNR metric, defined through the mean square error (MSE), estimating the loss of image quality by comparing the received video with the downloaded (reference video) are presented. The VQM (Video Quality Metric) metric is considered, which evaluates the distortion in the transmitted video caused by the passage of network packets through the cable line of the transmission system (decoding errors or coding errors), as well as methods for subjective and objective evaluation of images in video conferencing. The advantages and disadvantages of each of the evaluation methods are considered.