Digital Image Authentication, Forensic Image Analysis

What is Digital Image Authentication?

Digital image authentication services assist the trier of fact to determine the authenticity of a digital image used as evidence. Digital images created by digital cameras aren’t always an accurate eyewitness. With the increasing use of photo manipulation software, image compression and the Internet, image authentication is often necessary.

The Rules of Evidence require that digital images used as evidence in court be authentic. An image forensic expert provides forensic analysis of images used as evidence to Trier of Fact can make determiantions. These determinations will be based around what the evidence images represent. Tampered images are always detectable through image forensic analysis. 

Forensic Image Analysis Services

Image Authentication Science


“Image authentication is used to determine whether the imagery is a true and accurate representation of subjects and events. Similarly, image authentication does not answer specific questions about the subject(s), object(s), or event(s) within an image, such as “Is a specific object present?” “What happened?” or “Where is the scene depicted?” These are all examples of questions answered through image content analysis.

Image authentication must not be confused with the requirement to demonstrate the integrity of the evidence as a precondition to admissibility in court. Integrity ensures that the information presented is complete and unaltered from the time of acquisition until its final disposition. For example, the use of a hash function can verify that a copy of a digital image file is identical to the file from which it was copied, but it cannot demonstrate the veracity of the scene depicted in the image.

Image authentication and image content analysis may be performed in conjunction, depending on the use of the imagery.”

-PG 4 SWGDE best practices for digital image authentication

Preliminary Analysis

First, we begin all digital image authentication investigaitons with a preliminary analysis of the original image.  Throughout this process, our experts review the images in depth. The goal of the initial analysis is to determine if any signs of tampering or other red flags are present. In other words, this allows us to learn more about your images before proceeding to more costly and detailed forensic testing.

Our forensic lab is fully automated to support an expedited turnaround on large quanitites of images. 

Image Structure Analysis

Above all, the goal of the image structure analysis is to authenticate the circumstances to which the image was captured. Throughout this process we examine the digital information within the image. This helps us to  determine if the image contains similarities or differences with an original digital image. This original recording produced by the system creates it as a 1st generation copy.

Similarly, we perform a 4 part digital information test that analyzes camera specifications of the image. This information includes footprints of photo editing software used to manipulate the digital image, such as Photoshop. In other words, malicious editing and tampering is detectable through photo tampering detection.

Image Content Analysis

Digital Image Authentication, Forensic Image Analysis

Error level analysis testing results

Next, the image authentication investigation doesn’t stop with the digital structure. We will analyze physical aspects of the scene including lighting, scale and composition. We can also analyze the photogrpahic conditions which include focus, depth of field, sharpness, persepctive, gain structure, noise and lens distortion.

For example, when cloning or copying methods of physical images are used, a loss in quality is observed and documented. In addition, quality loss is detectable through digital image conversion to courtroom ready formats (JPEG, BMP, TIFF, PDF and many more). Clone detection error levels are highest when images are coppied improperly or converted using third party utilities.

However, if  the quality of a digital image is too low due to image compression (jpeg compression), it will lack authenticity.  In other words, it lacks the necessary criteria to make an accurate identification of a suspect, vehicle or other object. Compression levels, quantization tables and other tests will asssit the expert in arriving at a confident conclusion about compression.

Exemplar Sample Comparison Testing

In addition, exemplar comparison of images is crucial to an investigation. The comparison of an exemplar (known image) with the evidence (unknown sample) will help the court understand what a digital original looks lile. In order to create an exemplar accurately, you must determine the type of equipment (camera) that created the original digital image.

For instance, then you can obtain or gain access to that equipment and create test sample for analysis. This is the most accurate way to confirm the authenticity of the digital image, if the original evidence is unavailable.

Expert Witness Testimony

In conclusion, If the image authentication investigation needs to be presented in a court of law, an expert can help. Helping the tier of fact to understand the scientific analysis in a simple way is important to our experts.

Our experts can generate a formalized report outlining our qualifications, authentication methodology and opinions. This assists the trier of fact make determinations about the images used as evidence. When we prepare for testimony, we anticipate all questions that will be asked of us during direct and cross examination.

Our image forensic expert Michael Primeau has experience testifying as an image expert witness.  He has testified in local and state courts all over the USA and worked with lawyers around the world.

Client Reviews
As a business owner myself, I am aware of the effort it takes to assemble a team of employees that conduct their business as if it were their own, and take pride in how they represent your company to others. As an owner who feels has achieved that status myself, I immediately recognize it in others. I must say that this is not common in the workforce today. From the first contact with your company, through closeout, every one of your employees made this experience a pleasure and acted with the upmost more
Abc Def
20:32 03 Dec 18
Primeau Forensics is a professional, top-flight organization that knows how to access and deliver verifiable forensics information quickly, efficiently and productively. Don't let their cheerful, friendly attitude make you think they are not on top of their game--they are!read more
dan schulte
18:35 12 Dec 18
I received credentials from two technicians, then a third person ended up doing all the work and kept in touch with me by e-mail. I never saw any proof that the work was done and they told me they found nothing. They could not tell me what was making the noise or the lights. A waste of $ more
Teresa Galyon
16:13 13 Dec 18
Excellent work. Primeau took a low light camera recording of vandalism at my home and converted the video to images that we used to identity the vandals. Additionally, Primeau was able to identify characteristics of the vandals car that were used for a positive identification. Services were efficient, timely, and professionalread more
Todd Conte
15:18 27 Aug 18
Ed and his team are great! I took in footage of my boyfriends dog being stolen and they were so willing to take every step possible to enhance the video to retrieve the information we needed. The resolution on our camera/video wasn't great (our fault, not theirs) and they were unable to get the information we needed BUT they guided me in the next steps to take. Thank you guys!!read more
Anita Tela
12:47 23 Oct 17
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