Assessing the visual effect of non-periodic temporal variation of quantization stepsize in compressed video

This work investigates the impact of non-periodic quantization step size variation on perceptual video quality. We composed non-periodic temporal variation patterns from periodic variation patterns. We present subjective test results and examine how does the overall quality under non-periodic variation relate to the qualities of individual periodic components, and how does it relate to the instantaneous qualities at different time points. We propose two quality models based on our observations and data analysis. Such quality assessment and modeling are essential for designing video adaptation strategy when delivering video over dynamically changing wireless links.