DiffImg is a simple image comparison tool which take two images with the same size as input. Some statitics are computed and the positions where pixel differ are displayed as a color mask.

There are very few image difference tools for Ubuntu Linux. DiffImg is one of them which has a user friendly GUI. It uses OpenCV as backend so it can read and compare 8/16/24/32 bits images without problem but only single channel and RGB image has been take into account, so alpha channel isn’t supported.

Because DiffImg is written with Qt, it runs on Windows and Linux (MacOSX isn’t tested yet) and OS/2. It can read basic formats as BMP, PNG, JPG but also Tiff and OpenExR.

Current Features:

• Image difference display : a yellow/red mask can overlay the original/modified images.
• Single/Dual panels mode.
• Statistic computation: Mean error, RMS error and min/max are computed.
• Several metrics can be used for computing image difference.
• Histogram of error.
• “Slideshow” : DiffImg can compare directory of image, so you can switch to the previous/next comparison if you have two folders with the same image list.
• Supported files :DifffImg uses Qt plugins to load images, so by default it can read basic formats as BMP, PNG, JPG and OpenCV supported formats (Tiff, OpenExR).
• Basic batch mode

Install DiffImg:

A PPA repository has been created to make it easy to install for Ubuntu and Linux Mint users. So far, it supports Ubuntu 13.04 Raring, 12.10 Quantal, 12.04 Precise and Linux Mint 13 Maya, 14 Nadia, 15 Olivia.

To add the ppa, press Ctrl+Alt+T on your keyboard to open terminal. When it opens, run below commands:

sudo add-apt-repository ppa:dhor/myway

Then you can update package lists and install the tool via Synaptic Package Manager, or run below command:

sudo apt-get update; sudo apt-get install diffimg

That’s it.

For other systems, Diffimg source code and exe file can be download from SourceForge.