Congratulations to Qingyang Zhou on successfully defending his dissertation today! His thesis, titled “Advanced Techniques for Point Cloud Quality Assessment, Surface Reconstruction, and Coding,” was reviewed by his committee—chaired by Jay Kuo, with Antonio Ortega as a member and Stefanos Nikolaidis serving as the outside examiner. The committee praised the rigor and excellence of Qingyang’s research. Here is a summary of his thesis:
Point clouds (PCs) play a critical role in 3D vision and graphics applications such as AR/VR, digital preservation, and medical imaging. However, their large data volume, vulnerability to quality degradation, and the need for surface reconstruction from sparse, noisy points pose long-standing challenges. In this work, we address these issues through three research thrusts: compression, quality assessment, and surface reconstruction. First, we propose GPCGC, a low-complexity geometry compression method that leverages vector quantization and block-level rate-distortion modeling to achieve fast encoding/decoding with competitive performance. Second, we introduce GPQA, an interpretable, saliency-guided quality assessment framework that projects local 3D structures into 2D patches and uses a green machine learning model to predict perceptual quality under both full- and no-reference settings. Third, we develop two surface reconstruction methods: GPSR, an unsupervised diffusion-based approach, and LPSR, a supervised variant under the green learning paradigm. Together, these contributions advance the efficiency, interpretability, and robustness of the point cloud processing pipeline, enabling practical deployment in resource-constrained environments.
He generously shared his experiences in the MCL Lab with us:
My PhD journey at the University of Southern California’s Media Communications Lab (MCL) has been one of the most rewarding chapters of my life. Under the guidance of Professor C.-C. Jay Kuo, and with the generous support of MCL alumni and lab members, I not only deepened my technical knowledge but also grew into an independent problem solver.

The collaborative spirit of the lab, the high standards, and the culture of mentorship constantly challenged and inspired me. Through this experience, I’ve developed critical thinking skills, gained confidence in my research abilities, and found the courage to pursue bold ideas.

It has been a true privilege to work alongside such passionate and driven individuals. I will always treasure the friendships, the teamwork, and the intellectual exchange that shaped my years here.

This is not the end, but a new beginning. I look forward to continuing my work in this field, carrying forward everything I’ve learned here.