3D high definition video coding on a GPU-based heterogeneous system

H.264/MVC is a standard for supporting the sensation of 3D, based on coding from 2 (stereo) to N views. H.264/MVC adopts many coding options inherited from single view H.264/AVC, and thus its complexity is even higher, mainly because the number of processing views is higher. In this manuscript, we aim at an efficient parallelization of the most computationally intensive video encoding module for stereo sequences. In particular, inter prediction and its collaborative execution on a heterogeneous platform. The proposal is based on an efficient dynamic load balancing algorithm and on breaking encoding dependencies. Experimental results demonstrate the proposed algorithm's ability to reduce the encoding time for different stereo high definition sequences. Speed-up values of up to 90× were obtained when compared with the reference encoder on the same platform. Moreover, the proposed algorithm also provides a more energy-efficient approach and hence requires less energy than the sequential reference algorith

Paired comparison-based subjective quality assessment of stereoscopic images

As 3D image and video content has gained significant popularity, subjective 3D quality assessment has become an important issue for the creation, processing, and distribution of high quality 3D content. Reliable subjective quality assessment of 3D content is often difficult due to the subjects’ limited 3D experience, the interaction of multiple quality factors, minor quality differences between stimuli, etc. Among subjective evaluation methodologies, paired comparison has the advantage of improved simplicity and reliability, which can be useful to tackle the aforementioned difficulties. In this paper, we propose a new method to analyze the results of paired comparison-based subjective tests. We assume that ties convey information about the significance of quality score differences between two stimuli. Then, a maximum likelihood estimation is performed to obtain confidence intervals providing intuitive measures of significance of the quality differences. We describe the complete test procedure using the proposed method, from subjective experiment design to outlier detection and score analysis for 3D image quality assessment. Especially, we design the test procedure in a way that quality comparison across different contents is enabled while the number of pair-wise comparisons is minimized. Experimental results on a stereoscopic image database with varying camera distances demonstrate the usefulness of the proposed method and enhanced quality discriminability of paired comparison in comparison to the conventional single stimulus methodology