Subjective comparison of temporal and quality scalability

Objective assessment of the impact of frame rate on video quality

“…As reference data for this study, we have used the data obtained from the study published in [7]. The purpose of the original experiment was to find the quality optimal path through the plane, where one dimension is the quality measured in terms of peak signal-to-noise ratio (PSNR), and one other dimension is the frame rate.…”

“…With this method, it is possible to find the average preferred path from the lowest to the highest frame rate and PSNR, reflecting the perceived relative importance of frame rate and PSNR along the path. The details of the study are omitted due to the lack of space, but interested readers may refer to [7].…”

“…The method can be applied regardless of the sign of ΔPSNR. The data from [7] contains the preferred paths for five sequences judged by 25 test subjects, across planes with six frame rates and PSNR levels, ie. there are 6x6 nodes in each graph.…”

“…To make the comparison, we have created the preferred paths as in [7], derived from the quality values produced by the metrics named above. Based on the relative quality differences between adjacent nodes, we have computed the transition probabilities p a and p b for each node and then computed cumulatively the relative amount of occupants in each node, starting from the lowest frame rate and quality.…”

Analysis of the impact of temporal, spatial, and quantization variations on perceptual video quality

“…It was also pointed out that a minimum threshold value of 0.1 Bits Per Pixel (BPP) is required to achieve good or excellent perceptual quality. Subjective experiments conducted using low resolution videos, CIF, in [6] show that frame rate can be compromised to maintain the perceptual quality by keeping the compression ratio at low value. Similar results can be observed in the study reported in reference [7].…”