Applied Math Colloquium

Methods for accelerating x-ray tomographic reconstruction

Ming Jiang

School of Mathematical Sciences

Peking University

5 Yi He Yuan Street, Beijing 100871, China

E-mail: ming-jiang@pku.edu.cn

In addition to multi-CPU clusters, GPU and DSP, FPGA (field-programmable gate array) is another hardware accelerating approach. High-level synthesis tools from C to FPGA can optimize the implementation under the performance, power, and cost constraints, and enable energy-efficient accelerator-rich architecture. In previous work, we used FPGA for the simultaneous image reconstruction and segmentation with Mumford-shah regularization for XCT under Gamma-convergence, and achieved 31X speed-up and 622X energy efficiency compared to CPU implementation. However, FGPA was only used to accelerate the computation of forward and backward projections. Because of the limited memory on chip, recently, we propose asynchronous parallel Kaczmarz (ART) and RAMLA methods with diminishing relaxations. Preliminary results demonstrate better early reconstruction images with both methods. This asynchronous parallel approach fits well with the architecture of FPGA and reduces the communication cost, and is applicable to other parallel architectures in general (e.g. multi-core CPUs). In this talk, we also discuss more general asynchronous parallel data-block and image-block iterative methods with regularization, and approaches to establish their convergence from theoretical perspective. This is a joint work with Jason Cong, Yijin Guan, Peng Li, Guojie Luo, Peter Maass, Thomas Page, Li Shen, Pei Wang, Peng Zhang, Wentai Zhang.

姜明，北京大学数学学院信息科学系教授。从1980 年至1989 年在北京大学数学系学习，获博士学位。从1989 年到1995年在北京理工大学应用数学系工作。1996 年到1997 年在意大利International Centre of Theoretical Physics, Microprocessor Laboratory 进行研究工作。1998 年至今在北京大学数学科学学院信息科学系工作。目前是“Sensing and Imaging”主编， “Inverse Problems”， “BioMedical Engineering OnLine”， “International Journal of Biomedical Imaging”， “Signal Processing”等期刊编委。对图像重建的迭代算法、数字图像的盲反卷积方法和生物自发萤光CT技术进行了深入研究。与合作者建立了生物自发荧光CT的数学理论，发表了生物自发荧光CT方面的第一篇期刊论文。2004年获得国家杰出青年科学基金。2008年被聘为教育部长江学者特聘教授。

报告时间：2015年11月20日11:00-12:00

报告地点：数学科学研究院316会议室（环境学院楼316）