PHOTO ANALYSIS SOFTWARE

Size: px

Start display at page:

Download "PHOTO ANALYSIS SOFTWARE"

Tabitha Austin
6 years ago
Views:

2 Is seeing believing? Every day, public agencies process thousands of images in support of investigations or other types of claims. Until now, there hasn t been a fast and effective way to determine if the images are authentic. Meet Axon Detect. Axon Detect is an image analysis program for tamper detection. It goes beyond image-matching to offer you a robust suite of authentication tools to certify evidence in-house. This reduces the need for external consultants, shortens turnaround time, and lets you use evidence captured by the public. To illustrate the power of Axon Detect, let s work a case together. In this case, an image has been submitted to a typical traffic court to support a vehicle owner s assertion that the impounding of their car wasn t justified. If the court rules in the owner s favor, the city will have to refund hundreds of dollars in towing and impound fees. At issue is the reason for the impound. The city had the vehicle towed because it was parked in front of a fire hydrant. The vehicle s owner asserts that there is no fire hydrant at the location. The picture that was submitted to the traffic court clearly shows that there is no fire hydrant at the location. But, can you trust the image? Search the internet and you will find countless ways to create image forgeries. All one need do is download a free photo editor and photoshop out parts of an image. People can get very creative in trying to cheat the system. You can fool the eye fairly easily. But, there are a lot of things to account for when creating a good forgery. Axon Detect has over 20 filters that can be utilized to test an image. There are two basic types of exams, a blind test (tell me if it s authentic) and a test of a specific allegation (tell me if an item has been removed/added). Within the interface, red text means that there s a problem. Something s wrong. Something requires further inspection.

Back to the investigation... The image that you see on your monitor is a graphical representation of the fundamental binary data that constitutes a computer file.

It s in this HEX view that all sorts of valuable information is hiding; like the fact that the image in question was edited by Photoshop on a Windows computer. Reading HEX can be a chore.

There are other types of information hidden in the file. This information has to do with the file s container and data about the file itself. This information can be found with the EXIF Viewer.

3 Back to the investigation... The image that you see on your monitor is a graphical representation of the fundamental binary data that constitutes a computer file. The standard numerical format for representing binary data is called hexidecimal, or HEX for short. It s in this HEX view that all sorts of valuable information is hiding; like the fact that the image in question was edited by Photoshop on a Windows computer. Reading HEX can be a chore. With Axon Detect, you don t have to. Axon Detect sifts through the HEX data to find plain English words; words like Photoshop, GIMP, and Picasa to name a few. There are other types of information hidden in the file. This information has to do with the file s container and data about the file itself. This information can be found with the EXIF Viewer. Programs like Adobe s Photoshop add a ton of EXIF metadata to files. With the EXIF Viewer, you can see each of these entries. Now ask yourself, would a image taken directly from a mobile phone s camera and sent to a Traffic Court have an entry indicating that it had been processed with Adobe Photoshop on a PC? But, there are programs out there that can strip all of these fields clean. EXIF metadata is not permanent. It s designed to be altered. Thus, a better solution is needed. One that looks at the underlying structure and math that makes up the image. This is where the true power of Axon Detect is demonstrated.

Every time an image is saved, there s a ton of math involved in the process. Math, thankfully, has rules. When the rules are obeyed, there s no problem to detect.

When an image is saved, changed, and saved again, there are multiple and different compression levels present in the image.

4 Every time an image is saved, there s a ton of math involved in the process. Math, thankfully, has rules. When the rules are obeyed, there s no problem to detect. When the rules are broken, it becomes visually evident in many of the filters found in Axon Detect. When an image is saved, changed, and saved again, there are multiple and different compression levels present in the image. Error Level Analysis can be used to test against an allegation of cut/paste or deletion forgery. In this case, you can clearly see in the ELA filter view the fire hydrant has been removed. Ordinarily, at this point, the image would be declared to be a forgery and appropriate measures taken. But, let s take a look at some of the other quick and easy ways of illustrating the forgery present in this image. By mapping the Discrete Cosign Transform, the user can see the discontinuities in the compression of the image. Here, the DCT Map view clearly illustrates the changes to the image - the removal of the fire hydrant and the changes to the sidewalk to account for the missing item. To make this change easier to detect, the ADJPEG (Aligned Double JPEG) Filter clearly shows the area that has been changed.

At this point in the investigation, the image is clearly not authentic... Introducing false evidence into a proceeding is a felony in most jurisdictions.

Once the image is removed from the device, it can be loaded into Axon Detect as the Reference Image.

In this one case, the ability to determine that the submitted image was a forgery saved the agency and it s host city over a thousand dollars.

5 At this point in the investigation, the image is clearly not authentic... Introducing false evidence into a proceeding is a felony in most jurisdictions. Once identified as a forgery, the agency will want to request the source of the image; in this case it s a mobile phone. Once the image is removed from the device, it can be loaded into Axon Detect as the Reference Image. Remember, red text means that there s a mismatch between the Evidence Image and the Reference Image. A mismatch means, unequivocably that the Evidence Image is not authentic - a forgery. In this one case, the ability to determine that the submitted image was a forgery saved the agency and it s host city over a thousand dollars. When you consider the amount of images that agencies receive each day, it becomes easy to see how quickly Axon Detect will pay for itself. If you re in a state with an evidence code that requires each image be scientifically authenticated prior to admission in trial, you absolutely need Axon Detect. It works great on single images. It also works on large volumes of images. Other tools include searching the web for similar images (great for social media investigations), showing the image s location on Google Maps (where was the image taken), and searching for images from the same camera model. But, don t take our word for it. We re happy to share a fully-functional trial version with you. See for yourself how fast it is. Test it against images in your system. Create your own forgeries and see if Axon Detect can spot them. Contact your Axon salesperson today, or visit our web site.

PHOTO ANALYSIS SOFTWARE

PHOTO ANALYSIS SOFTWARE The problems with social media images As a general rule, there are three basic ways of authenticating an image prior to trial. The first way involves the photographer attesting to the image s authenticity.