Congratulations to Haiqiang Wang for passing his PhD defense on August 21, 2018. His PhD thesis is entitled “A Data-Driven Approach to Compressed Video Quality Assessment Using Just Noticeable Difference”.

Abstract of thesis:

The problem of human-centric compressed video quality assessment (VQA) is studied in the research. In this thesis, he propose a new methodology for compressed video quality measurement and assessment based on the just-noticeable-difference (JND) notion. The process of building a large-scale coded H.264/AVC video quality dataset is described. Then, he measure the JND-based video quality using the satisfied user ratio (SUR) curve and designing an SUR prediction method with video quality degradation feature and masking feature. The method consists of the following steps: 1) partition a video clip into local spatial-temporal segments and evaluate the quality of each segment using the VMAF quality index, 2) aggregate these local VMAF measures to derive a global index, 3) significant segments are selected based on the slope of quality scores between neighboring coded clips, and 4) incorporate the masking effect that reflects the unique characteristics of each video clip. Then use the support vector regression (SVR) to minimize the distance of the SUR curves, and derive the JND point accordingly. At last, propose a JND-based VQA model that takes subject variabilities and content variabilities into account. He build a user model by utilizing user’s capability to discern the quality difference. He study the SUR difference as it varies with user profile as well as content with variable level of difficulty. The proposed model aggregates quality ratings per user group to address inter-group difference.

We are so glad to have him share his PhD experience with us. Here is his sharing.

I would like to thank Professor Kuo for his support, patience, encouragement and thoughtful feedback throughout my PhD studies. Professor Kuo was and remains the best role model for me in many ways, highly disciplined, self-motivated, persistence and endurance. Sometimes life is tough. However, those frustrations will make you mentally mature and the difficulties will make you stronger. I appreciate the help I received during tough times, both from friends nearby and those who are in a long distance. Good luck and wish you all the best in the future.

Congratulations again to Haiqiang and we wish him all the best in his future career.