Digital images that are tamper-proof

December 2002 Surveillance

Digital pictures that have been tampered with can now be detected by a 'watermark' developed by scientists at Bristol University, England. Digital images such as CCTV footage are increasingly being used as evidence in court cases in the UK, but tampering with them has been difficult to detect.

Researchers have created a digital version of a watermark to tackle this problem and validate the image. Prof Dave Bull says that the watermark can be introduced on either still or video images to validate their authenticity and reveal any changes made to the original version. Prof Bull said: "With a high-tech problem, we needed a high-tech solution, but drew our inspiration from the humble paper watermarks first created in the 18th century."

Paper watermarks were patterns put into paper during its production while still wet. This gave the paper an identity mark that was used by manufacturers as a security measure to avoid forgery of important documents such as bank notes and passports.

The old watermarks were created by forming a seal around the image in its original state. The digital watermark is applied automatically at the point when the image is taken by incorporating appropriate software into the camera. Encoded information within the watermark will show if it is subsequently tampered with.

"The idea is that if the image file is passed through a special statistical detector it will be able to read the digital watermark and determine whether it has been altered. For example, the hands on a clock might have been changed to show a different time, or a face might have been obscured," said Prof Bull.

He hopes that the research will be adopted by digital film and camera manufacturers, and applied as part of an industry-wide security standard. The watermark uses patent-pending technology based on the use of mathematical algorithms.

For more information contact Prof Dave Bull, dave.bull@bristol.ac.uk





Share this article:
Share via emailShare via LinkedInPrint this page



Further reading:

Pentagon appointed as Milestone distributor
Elvey Security Technologies News & Events Surveillance
Milestone Systems appointed Pentagon Distribution (an Elvey Group company within the Hudaco Group of Companies) as a distributor. XProtect’s open architecture means no lock-in and the ability to customise the connected video solution that will accomplish the job.

Read more...
Embracing next-generation surveillance for safer cities
Surveillance Integrated Solutions AI & Data Analytics
With the South African government highlighting the importance of building smart cities by integrating advanced technologies to make them more resilient and liveable, the role of next-generation network video and surveillance technologies cannot be ignored.

Read more...
Hik-Connect for Teams released
Hikvision South Africa Products & Solutions Surveillance
Hikvision has released an update for its security management platform; Hik-Connect for Teams not only meets the specific needs of individual users, but also caters to various medium-sized businesses (SMBs) and multi-site management scenarios.

Read more...
The human factor side of video management systems
Leaderware Editor's Choice Surveillance Risk Management & Resilience
A video management system (VMS) is central to, and the most vital element to any control room operation using CCTV as part of its service delivery, however, all too often, it is seen as a technical solution rather than an operational solution.

Read more...
A simple system for complex protection
Surveillance AI & Data Analytics IoT & Automation
Reconeyez is a company that provides autonomous wireless visual verification systems with built-in artificial intelligence. Running on batteries, each device includes communication capabilities, creating a mesh network between the various devices, linking them to the control room.

Read more...
Revolutionise your security with integrated solutions
Secutel Technologies Products & Solutions Surveillance
By merging the capabilities of SecuVue and Secutraq, Secutel has forged a robust system empowering users to fine-tune analytics and harness facial recognition, pose detection, and XFS, among other features.

Read more...
Safer roads to a sustainable future
Dahua Technology South Africa Surveillance
With the ever-increasing number of vehicles on the road, it is imperative to constantly improve the quality of transportation monitoring and traffic management in urban and rural areas.

Read more...
From damage management to false alarm prevention
Dallmeier Electronic Southern Africa Transport (Industry) Surveillance Logistics (Industry)
Video surveillance is undergoing an exciting evolution; today’s IP-based solutions can be fully integrated into digital systems. With the increasing integration of artificial intelligence (AI); logistics, in particular, can make processes more transparent and exploit previously untapped potential.

Read more...
Marshall Security partners with Blacklight to introduce Reconeyez to KZN
News & Events Surveillance Power Management
Marshal Security has joined forces with Blacklight Group to launch Reconeyez, a cutting-edge battery-powered surveillance platform with mesh network capability, in the KwaZulu-Natal market.

Read more...
Professional mobile video management in your pocket
Dallmeier Electronic Southern Africa Surveillance
With the SeMSy Mobile Client for its Domera and Panomera cameras, Dallmeier is now launching a solution that combines the functional and security requirements of professional organisations with the user-friendliness and simplicity of consumer apps.

Read more...