image comparison tool
Download from PortableApps.com
DiffImg Portable can run from a cloud folder, external drive, or local folder without installing into Windows. It's even better with the PortableApps.com Platform for easy installs and automatic updates.
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. The image comparison mode can show a red/yellow mask overlay to highlight differences. Single or dual pane views are available as well as a histogram of the errors.