html在marquree标签,Objective video quality assessment

Objective Video Quality Assessment 1061 of visual perception is based on the assumption that the HVS functions similarly it has adapted to extract structural information and to detect changes in structural information. By contrast, an error sensitivity based approach estimates perceived errors to represent image degradation. If it works properly, then a significant perceptual error should be reported for the contrast stretched image because its difference (in terms of error) from the original image is easily discerned.

Figure 41.9 Evaluation of “Lena” images with different types of distortions. Top-left: Mean shifted image, MSE=225, Q=0.9894; Top-right: Contrast stretched image, MSE=225, Q=0.9372; Bottom-left: Blurred image, MSE=225, Q=0.3461; Bottom-right: JPEG compressed image, MSE=215, Q=0.2876. Third, the new philosophy uses a top-down approach, which starts from the very top level simulating the hypothesized functionality of the overall HVS. By comparison, the error sensitivity based philosophy uses a bottom-up approach, which attempts to simulate the function of each relevant component in the HVS and combine them together, in the hope that the combined system will perform similarly to the overall HVS.

How to apply the new philosophy to create a concrete image and video quality assessment method is an open issue. There may be very different implementations, depending on how the concepts of “structural information” and “structural distortion” are interpreted and quantified. Generally