Next-Generation Methods for Image Sequence
Analysis, Processing, and Transmission

This research thrust concentrates on advanced processing of image sequences with the goals of more accurate analysis (e.g., segmentation), improved compression, and extraction of qualitatively new information (e.g.,occlusion and newly-exposed areas). See projects below for more details.

Video Condensation by Ribbon Carving (2008-...)
Team: Z. Li, W. Liu, P. Ishwar, J. Konrad
Funding: National Science Foundation (CISE-CNS-NOSS)
Efficient browsing of long video sequences is a key tool in visual surveillance, e.g., for post-event video forensics, but can also be used for review of motion pictures and home videos. While various video summarization and synopsis methods have been developed to date, most methods are either ineffective or computationally complex. Inspired by image seam carving, a method for content-aware image re-sizing, we have developed a novel approach to video synopsis, that we call video condensation. The method is novel in the way information is removed from the space-time video volume, is conceptually simple and relatively easy to implement.

Joint space-time segmentation and analysis of video sequences (2001-2006)
Team: M. Ristivojevic, J. Konrad, collaborators from the University of Nice, France
Funding: National Science Foundation (CISE-CCR-SPS, Intern. Collab. USA-Frrance)
Traditional video processing methods use two image frames at a time to analyze such dynamics as motion, occlusions, etc. We explore new framework that is based on joint treatment of many image frames (e.g., 20-30). A form of joint space-time processing, this framework is essentially three-dimensional (3-D) since its domain is the x-y-t space of image sequences. It is expected to result in more reliable video segmentation, detection of occlusion effects and identification of various dynamic events. To date, we have developed a video segmentation method within this framework that is based on an active-surface model and level-set solution. Applied to both synthetic and natural image sequences this method results in "object tunnels" in the x-y-t space, that we have used successfully to identify certain occlusion events and measure time instants of object occlusions, disappearance, entry, etc. See the above link for more details and results.

Video sequence compression based on spatio-temporal transformations (2001-2006)
Team: N. Bozinovic, J. Konrad, collaborators from the University of Nice, France
Funding: National Science Foundation (CISE-CCR-SPS, Intern. Collab. USA-France)
It is widely believed in the research community today that the next significant video coding gains will come from a joint compression of multiple video frames, such as offered by 3D wavelet coding. We have been studying the behavior of video data subject to various 3-D (x-y-t) transformations. We have developed a multiple-frame characterization of linear motion in the DCT domain. An extension of the fundamental result in Fourier domain, this outcome allows us to better understand spectral composition of 3D-DCT-transformed video data. Based on this, we have developed 3D DCT coefficient scanning patterns that are more efficient than scans used to date, and may lead to efficient 3D transform-based video coding techniques.

"iPark" - Vision-Based Parking Monitoring System (2004-2005)
Team: J. Konrad, W.C. Karl, M. Mole, P. Ward, I. Hochman, K. Lopez
Capstone Design Project for Senior-Year Students
With the difficulty of finding an empty parking spot at airports (have you tried Boston’s Logan International Airport recently?) and shopping malls a clear need arises for a system permitting automatic localization of available parking and alerting users. In this senior design project, a team of four BU students under the supervision of Profs. Konrad and Karl has built a complete system for monitoring a parking area, detecting empty parking spots and alerting users to such spots via a graphical user interface (large screen, PDA, cell phone, etc.). The system is vision-based and uses commercial IEEE 802.11 wireless cameras and standard PCs. At a recent IEEE Student Design Contest the system took top prize and was featured on WHDH Channel 7 News and several web sites.