TY - GEN A1 - Amiri, Mitra A1 - Le Moan, Steven A1 - Herglotz, Christian T1 - Exploiting Change Blindness for Video Coding: Perspectives from a Less Promising User Study T2 - 16th International Conference on Quality of Multimedia Experience (QoMEX) N2 - What the human visual system can perceive is strongly limited by the capacity of our working memory and attention. Such limitations result in the human observer’s inability to perceive large-scale changes in a stimulus, a phenomenon known as change blindness. In this paper, we started with the premise that this phenomenon can be exploited in video coding, especially HDR-video compression where the bitrate is high. We designed an HDR-video encoding approach that relies on spatially and temporally varying quantization parameters within the framework of HEVC video encoding. In the absence of a reliable change blindness prediction model, to extract compression candidate regions (CCR) we used an existing saliency prediction algorithm. We explored different configurations and carried out a subjective study to test our hypothesis. While our methodology did not lead to significantly superior performance in terms of the ratio between perceived quality and bitrate, we were able to determine potential flaws in our methodology, such as the employed saliency model for CCR prediction (chosen for computational efficiency, but eventually not sufficiently accurate), as well as a very strong subjective bias due to observers priming themselves early on in the experiment about the type of artifacts they should look for, thus creating a scenario with little ecological validity. KW - Accuracy KW - Biological system modeling KW - Semantics KW - Bit rate KW - Blindness KW - Predictive models KW - Observers Y1 - 2024 U6 - https://doi.org/10.1109/QoMEX61742.2024.10598281 SN - 2472-7814 SN - 2372-7179 EP - 43 PB - IEEE ER - TY - GEN A1 - Le Moan, Steven A1 - Amiri, Mitra A1 - Herglotz, Christian T1 - Exploiting Change Blindness to Reduce Bitrate and Display Luminance in Video Streaming T2 - IEEE International Conference on Image Processing (ICIP) N2 - This paper investigates the potential of exploiting change blindness (CB), a perceptual phenomenon where changes in a visual stimulus are not noticed by the observer, to enhance rendering efficiency and achieve higher compression gains in video encoding. We explore various distortion techniques, including foveation, cropping, and dimming, to introduce changes that can be noticed but typically are not, due to the limited bandwidth of our perceptual experience. Through a user study involving HEVC-encoded videos and a task designed to direct gaze, we assess the impact of these distortions on perceived video quality, bitrate reduction, and display luminance. Our findings suggest that significant bitrate and luminance reductions can be achieved without adversely affecting perceived quality, highlighting CB’s potential for reducing energy consumption and strain on streaming infrastructure. Despite observer variability and the ephemeral nature of CB, our results demonstrate that conscious attention plays a crucial role in the perception of video quality and that exploiting CB can lead to substantial efficiency gains in video coding. KW - Video coding KW - Visualization KW - Image coding KW - Bit rate KW - Blindness KW - Streaming media KW - Observers Y1 - 2024 SN - 979-8-3503-4939-9 SN - 979-8-3503-4940-5 U6 - https://doi.org/10.1109/ICIP51287.2024.10648096 SN - 2381-8549 SN - 1522-4880 PB - IEEE ER -