I am a software developer working on video telephony at OpenMarket in London.
I have a PhD in Computer Science from the University of Cambridge Computer Laboratory, where I researched forensic analysis of visual signals in the Security Group.
Doctoral thesis: Reconstructing compressed photo and video data
I investigated tampering detection and recompression of previously JPEG-compressed images, copy-evidence in JPEG images (which was linked from Slashdot), and developed a tool that recovers H.264 video bitstreams from fragmented memories without relying on metadata. I presented this last project by invitation of the Metropolitan Police at ICDDF 2011. My research was supervised by Markus Kuhn.
Consulting
I have advised the Metropolitan Police Service and other law-enforcement agencies, several private investigators and journalists on image/video forensics and recovery. In 2011 I acted as an expert witness in a court case involving digital media streaming.