Forensic Uses of Digital Imaging

The book I read to research this post was Forensic Uses of Digital Imaging by John C Russ which is an excellent book. Digital imaging is often used in films and what many people don't realise is often building a set is impractical & too expensive so the actors perform in front of blue screens and the background is added digitally. Also when you see a weatherperson on television they're standing in front of a blue screen and things like the map and weater symbols are added digitally. Some people think you can add a background to a photo in something like photoshop and nobody can tell the difference and you can maybe falsely incriminate someone in this way. In reality it maybe possible but would be very difficult and would require a very skilled person to do it. If you changed the background in a photo there would almost certainly be clues to indicate this had happened. A program like 3d studio max might be able to do this job but it would take someone with great skill to pull it off. Digital imaging is used in gathering evidence at the scene of a crime. One issue is do you compress photos to send them by email and almost if they were relied on in court they would be thrown out. Another issue is guaranteeing the photos haven't been tampered with and one method is to copy them onto film and another is to store them on cdr along with a serial number. Basically both of them are a write once media. Another issue is taking a poor quality photo and extracting details from it. The enhanced picture can look very different to the original and it can be very difficult to prove its accuracy. The technique often involves blurring some parts with a gaussian blur and enhancing other parts which is probably best left to a professional.