With the development of technology and the increasing frequency of use of electronic devices in life, the importance of photo forensics is becoming more and more prominent, especially in the digital age. The proliferation of electronic devices and the prevalence of social media have made photos increasingly accessible. This brings great convenience to the investigation work. Whether in criminal investigations or other fields, photographs can provide valuable evidence. We can use modern technology to analyze and interpret the photos to better understand the case.
What is photo forensics?
Photo forensics is when investigators extract photos from electronic devices and verify their authenticity. Photos are image data, which can be directly used as evidence, and are frequently used in judicial cases.
Types of photo forensics cases
Photo forensics play an important role in a variety of cases, such as child abuse, pornography, and iconography infringement, through crime scene photos, we can establish the identity of the suspect, reconstruct the incident, and help judges and juries make the right judgment. For the search of missing persons, we can check the clues of witnesses through photos to improve the search efficiency. In addition, in the investigation of traffic accidents, photos can also provide powerful evidence to reconstruct the accident.
How to do photo forensics?
The shooting and preservation of photographic evidence shall comply with the provisions of relevant laws on the place of investigation and evidence collection. With the help of digital forensics software, such as MTM‘s latest photo forensics software, we can verify the authenticity of photos, and obtain more useful information through technical means, through color level adjustment, image fog removal, light and dark repair, color offset repair, image denoising, distortion correction, blur repair, defect removal and other functions to clear the image and help solve the case. At the same time, professionals in the field of digital image forensics can also ensure that photos are properly processed for court use.
Types of photographic evidence
- Screen shots of mobile phones and computer screens displaying information
- Taking photographs of documentary evidence and material evidence
- Taking photos of the scene of the incident
Preservation of photographic evidence
Photos are a way to store information, and it is necessary to confirm that key information is accurately captured (no missed shots, clear pictures), and ensure that the authenticity of the photos will not be questioned.
(1) Presenting the original carrier of photographic evidence.
(2) Photo format conversion.
Usually, the camera devices we use generate image files in JPG format. However, some devices are different, such as DSLR cameras that produce RAW image files, while the iPhone8 and iPhoneX use the HEIC format. Files in these special formats may not be read directly on some common devices. Therefore, we should try to use the device that took the photos to convert these files to JPG format, rather than importing them to the computer and then using software to convert them. Because of the use of computer software conversion, there may be a risk that the file will not be authenticated. Therefore, in order to avoid this situation, we should pay attention to the conversion of file formats on the appropriate device.
(3) Do not use beauty cameras or retouching software for photo processing
Because photos taken by normal cameras, many small color blocks of different shades will be found after magnification, which is the so-called “noise”. These noises are caused by the defects of the digital equipment itself, and the existing technology cannot avoid them. Although post-processing techniques can remove these noises, they cannot produce real noise. The noise generated by different devices has its own characteristics, and the noise simulated by graphics processing technology can be identified. Post-processing techniques often remove noise intentionally or unintentionally. Therefore, at the time of identification, for photos that have been optimized for effects, it may be concluded that “authenticity cannot be identified”.
(4) When sending photos, use file mode.
Some forums and chat software (such as wechat) will compress photos by default, although it will destroy the picture information, but it will also remove the exclusive information of the shooting device, which is not easy to identify.
(5) No modification shall be made to its contents.
This includes, but is not limited to, cropping, scaling, rotating, adjusting brightness, and contrast. If the extended information in the photo is incorrect due to any reason such as the camera device, such as the incorrect date of the shooting caused by not checking the time of the device, or the incorrect positioning data of the photo due to GPS signal problems, no tool should be used to modify it. Instead, written explanations should be provided.
Submit photographic evidence
At the time of prosecution, the CD and printed photos should be provided and organized into written materials to clearly prove the purpose and mark important content.
In court, bring the original carrier, and preferably provide a portable playback device that can view the photos in court. If you need to show details, you can print a large photo.
If the photo contains private, confidential and other information, you need to communicate with the judge before submitting evidence.
The use of MTM forensics products can reduce the trouble of evidence submission, and perfectly realize the efficient and integrated operation of the whole process of monitoring evidence extraction (recovery), fixing and analysis in the field investigation process, and evidence compliance can be directly adopted by the court to help judicial justice.
The significance of photo forensics
Through the proper use of photo forensics, we can more accurately resolve cases and ensure that justice is served. In order to ensure the reliability of photos, we should strengthen the understanding of digital image forensics and grasp the correct principles of photo forensics. Only then will we be able to harness the full potential of photo forensics and ensure that it is used to its fullest effect in investigations.
Peroration
Photo forensics technology is widely used in the judicial field as a means to record evidence. Scientific, legal and standardized collection, preservation, inspection and identification of photographic evidence is of great practical significance for maintaining social stability, protecting individual rights and interests and cracking down on crimes.