This article will start by defining video integrity and mentioning possible approaches to integrity verification. We’ll also make a very short introduction to some concepts of video coding and then, show how you can use Amped Authenticate’s VPF analysis to reveal traces of double compression in videos, and how important this could be as an integrity verification step.
When dealing with video evidence, integrity verification is a fundamental, yet often neglected, task. The definition of integrity can be summarized as: “the file is original and unaltered since the time of acquisition”. It’s plain and simple: the file should not undergo any change once it’s acquired, and if it does, every change should be documented in the chain of custody. Notice that integrity is different than authenticity, which has a more “semantical” meaning, as it requires the video to be an accurate representation of what it purports to be. If you re-compress a video, its authenticity will normally be preserved, but integrity is broken.
I know someone could think “the last thing I need is having to waste time checking one more thing in all my casework”. Understandable. At the same time, though, if one day I’ll be charged with something, I would really love to know that all the evidence pertaining to my case has been handled with the greatest care and I’m quite sure that holds for all readers of this article! If you’re in the forensic field, then you know that working with video is not just “common sense”. We’re not sorting our holiday pictures; we are handling evidence that could change somebody’s life, and dramatically so.
Dear friends, it is with a bittersweet feeling that I’m announcing this will be the last Tip Tuesday. The bitter part is just because I’m a bit emotional and I got used to this weekly appointment… but the sweet part is that we’ll continue writing new posts in 2021, just a bit different… so the best is yet to come!
To say goodbye, I’ve prepared a list of the 52 tips that accompanied this difficult 2020, so you have them all here for quick reference. And if you want, you can also take a look at the list of 2019 tips.
Thanks to all our loyal followers, we’ll meet again next year (#bringon2021) ready for a new experience!
Dear friends welcome to this waiting-for-Santa tip! Less than a week has passed since the latest Amped Authenticate update (if you’ve missed it, take a look here!), and we’re already providing a tip to make the most of the new Video PRNU tool! In particular, today we’ll deal with a case where we need to check whether a video comes from a device, but we only have reference images of it. We’ll see that, with the latest Authenticate update, this is very easy to do!
Dear friends welcome to this week’s tip! A question we get very often from our users is: which format should I choose to write my enhanced video/image once I’m done? We’re thus happy to introduce a mini-series of two tips on this subject! Today we’ll introduce the topic and discuss the case where your final output is an image, next week we’ll deal with videos. So, keep reading! And see you back here next week for part 2!
Dear Tip Tuesday addict, welcome to this week’s dose! Today we’re dealing with one of the latest features introduced in Amped Authenticate, the Shadows filter. We’ll see how the filter can help you identify the manipulated object, which is very handy when you’ve selected many shadows in the image. Keep reading!
Dear friends, welcome to this week’s tip! Inspired by a question from one of our users, we’re dedicating this tip to the various ways you can export results obtained with Amped Authenticate‘s filters. You’ll see there are different options that serve different needs, so… keep reading!
Dear Amped friends, welcome to one more tip! Following the recent mini-series about unveiling traces of double JPEG compression, today we’ll show how Amped Authenticate can reveal if a seemingly uncompressed image was actually JPEG compressed in its past. Keep reading to find out more!
Hello dear friends, ready for this week’s tip? Today we’ll be continuing the mini-series about investigating the life-cycle of digital images, specifically revealing previous JPEG compressions with Amped Authenticate. If you missed the first tip, it’s here for you, but you can also keep reading this one alone.
Hello, dear Amped blog fellows! This week we’re beginning a mini-series of two tips dealing with one of my favorite topics, image life-cycle investigation! They’re a bit more technical than usual, but I’m sure you’ll enjoy them. Today, we’ll see how we can use Amped Authenticate to look for traces of previous JPEG compressions in your evidence image, and in the next tip of the series, we’ll deal with estimating the quality of possible previous JPEG compressions. Keep reading!
Dear friends welcome to this week’s tip! I hope you didn’t miss the latest news about Amped Authenticate! With the last Update 17658, we’ve introduced a brand new filter category, called Geometrical Analysis, which includes the Shadows filter. Today we’ll demonstrate how to choose which shadow constraints to be added and which would not add any value. Avoiding useless constraints will make processing faster and produce more pleasant output images. Keep reading!