Is the image that you are looking at original, or has it been manipulated in an image editor? Image editors have become that good that it is virtually impossible to tell by looking at the image in question; unless it contains flying elephants or similar unrealistic things.
But what about that ufo image that your friend claims is real, photos on a dating site, or images that have been published on digital camera manufacturer sites?
While you can analyze the image, for instance its metadata to find clues about whether it has been manipulated or not, software may assist you in detecting manipulation.
JPEG Snoop is a tiny portable software program that can analyze the ins and outs of any digital image that the user loads in the program. Supported are various image formats including jpg, pdf, crw, dng, cr2, new, orf, pef, thm and even video formats such as mov and avi.
The software program displays many information about the image in a text editor like interface. The interesting part for users who want to identify if an image has been manipulated is displayed in the end. The program will compare the compression characteristics of the image, and assign an assessment class to it based on that.
Four assessment classes are defined:
To use the program, start if after you have unpacked it on your system. The application is portable which means that it does not need to be installed.
Click on file > open image to load the image that you want to analyze into the application. The scan is fast and displays results right away in the upper half of the interface.
Besides the assessment class that it gets assigned to, it displays a wide variety of parameters, from the average pixel luminance and brightest pixel to various file offset information.
While those may be useful for people in the know, for instance forensic analysts, it is of little value to end users.
Jpegsnoop offers several tools to assist in the analysis. You can use it to batch process files, look up mcu offsets or search executable files for DQT among other things. While batch processing is nice, the remaining tools will be mostly useful to analysts and not end users.
We mentioned earlier that JPEG Snoop is able to process video formats as well. It can analyze a single frame of a video that is loaded into the software. The program may be interesting for users who regularly need to analyze images to find out if it has been tampered with or not.
JPEG Snoop is a useful program for Windows that helps you analyze images for signs of manipulation. In best case, all that is required is to look at the assessment class as it reveals the program's findings after its scan to you.
Ghacks is a technology news blog that was founded in 2005 by Martin Brinkmann. It has since then become one of the most popular tech news sites on the Internet with five authors and regular contributions from freelance writers.