Low Bitrates: Problems and Solutions for Law Enforcement Cameras (Part 2)
Part 2 of 3 from the perspective of a cinematographer and forensic consultant.
THE PROBLEM
Bad video quality is part of the reason nearly half of robberies remain unsolved. Even an HD image is of little value if the images captured are both wide angle and low bitrate. Security cameras are often inadequate for fine detail — like identifying features.
Every year a bank has a 1 in 20 chance of being robbed* and only 1/5th of the money is ever recovered. It almost seems like theft insurance is easier than properly monitoring a building.
One retired bank robber, Clay Tumey, explained his lack of concern for cameras in an online Ask Me Anything “I researched for about five or six months prior to my first [robbery]. I studied mostly the things that people did to get caught”. When he was asked how he dealt with bank’s cameras he said he ignored them, “they’re shitty and unhelpful…I did end up on security cameras, but that doesn’t matter if they don’t know who I am”. By avoiding small towns and never doing anything newsworthy he managed to operate with impunity.
Clay stopped counting his robberies and only turned himself in out of an act of conscience.
TEMPORARY SOLUTION
One approach to recover detail comes from a technique called super-resolution. Super-resolution uses detail found from multiple images to increase resolution of a composite image.
Super-resolution from a video source is not a panacea. Video codecs use the similarity between frames to reduce file sizes. This makes super-resolution from stacking images challenging.
The most cutting edge super-resolution technique, one that identifies repeating image patterns and intelligently fills in the gaps, is great for amateur and commercial photography use but are not adequate for forensics. Most “intelligent” methods of increasing detail could be argued out of court for introducing details unfaithful to the original image.
HARDWARE SOLUTION
There are two solutions to low bitrate: using newer, more file size efficient codecs (h.265) or recording in higher bitrates.
*93,000 Branches in 2012 (AlixPartners), 5014 robberies in 2011 (FBI).
ABOUT THE AUTHOR
DANIEL VOSHART combines his background of cinematography and architecture for forensic consulting. He received a BA from Ryerson University and an M.Arch from the University of Toronto. His thesis was on Architecture and Virtual Reality.
