PhotoDetective: Image Forensic Toolkit
What is PhotoDetective?
Our current project is an application that enables users to determine if, and how, an image may have been altered. We have created a simple-to-use Graphical User Interface (GUI) so that anybody can take any image they find in commonly used formats (jpeg, png) and perform digital forensic analysis with only a point and a click of the mouse.
What can PhotoDetective do?
PhotoDetective allows users to open an image file and then select a forensic algorithm to perform on the image. These algorithms come from peer reviewed papers in the digital forensics field. Each algorithm tells a different part of the story behind the photo including:
- Is the lighting direction consistent?
- Was the entire shot at the same focal length?
- Have some parts of the image been compressed more than others?
- What color filter array did the camera use to shoot the picture?
- What quality level was the image saved at?
- What quantization table was the image saved with?
- Has an image been recolored?
- Are the jpeg artifacts distributed equally across the image?
- Is an area naturally or artificially blurred?
- What colors are the same in image?
- Does the image contain a hidden thumbnail of itself?
- Has the contrast been enhanced?
- What is the Exif Information?
- Is the camera clipping image colors?
How does PhotoDetective work?
PhotoDetective lets you run a variety of routines on an image, each that provides a little part of the full story behind the image. Specifically it uses the following algorithms and techniques.
- Principal Component Analysis to detect consistency among artifacts in the image
- Wavelet decomposition analysis to detect whether the image is all at the same focal length
- Edge detection routines to identify naturally blurred vs. artificially blurred areas (used to covered up tampering)
- Error level analysis to detect whether parts of the image come from sources with different error potential (i.e., two different images)
- Noise enhancement to make small artifacts more visible
- Local Min/Max pixel highlighting to determine if the pixels errors display a normal variation
- Lighting gradient coloration to visually show where the light is coming from in an image, and is it consistently in one direction
- Temperature Pseudocolor based on pixel intensity to identify odd or inconsistent coloration
- Pixel color randomization to show pixels that have the same RGB value more easily
- Extreme color highlighting to show where the pixels are pure white and black and if the colors are being clipped by the camera
- Thumbnail extraction from image to show what the picture might have originally looked like before manipulation
- Displaying Exif information to display properties concerning the image's history Extraction of Quantization tables used to save the image
- Minimum-Medium-Maximum RGB value for each pixel to identify coloration inconsistencies Save quality estimation to know what amount of compression has been used on the image.
- Display the histogram of colors to see if a contrast filter has been applied
- Color Filter Array Estimation to know what color filter arrangement the specific camera uses to interpolate the colors
What can I do with PhotoDetective?
PhotoDetective has many real world applications that would be of interest to far more people.
- Detectives interested in demonstrating whether an image is edited or authentic can perform a variety of routines that address specific types of alterations.
- Images of the human body in advertising are commonly edited to present a completely unrealistic standard of beauty; much of this editing can be exposed using our tool.
- Digital archivists can learn more about the authenticity of images.
- Consumers hesitant about purchasing a product can now be more informed if preview images have been altered to hide faults and defects.
- Insurance agencies interested in determining whether a claim is fraudulent can do so at the press of a button.
The interface was designed to be as intuitive and user-friendly as possible, while the coding was designed to be up to professional standards.
- Operating System: Windows XP, Vista, 7, 8, 10
- Architecture: Compatible with 32-bit or 64-bit systems
- Minimum Hard drive space required: 176 MB
- Minimum Ram required: 4GB
- $30.00 USD
- Perpetual License
- No Digital Rights Management Restrictions