The list below is meant to give you a rough idea of PhotoQt's abilities and is by far not an exhaustive list:
-Based on Qt5/QML
-Support of many image formats (use of GraphicsMagick and Libraw)
-Rotating, flipping, zooming images - no permanent changes
-Scaling images - permanent change
-Basic File Management (Renaming, Deleting, Moving, Copying)
-Keyboard and Mouse Shortcuts
-Highly Adjustable to your custom preference
-Interface that doesn't get into your way
-Very fast and flexible
-System Tray Usage
-Command Line Options
-Several translations available (not all complete (yet)... Wanna help?)
-and much more...
The program has a convenient and unusual interface. The control is via mouse and hot keys. In the left part of the window is a list of quick access folders and removable media. Right of the directory tree and the rest takes a list of images. Instead of a list you can display thumbnail. Thumbnail size can be changed with the slider, which is located at the bottom. If the mouse hover over any file, then right around the list will display its image in a larger view.
If you click on the file, then you will be taken directly to the view mode. The image appears on the screen, and you will be able with the mouse or keyboard to scroll images. Above the image, you can perform basic operations: rotation, reflection (flip), renaming/copying/deleting/moving the file, view the Exif data.
If the mouse to hold the right side of the screen, then POPs up a settings panel where you can perform basic settings on the file, and open the settings of the program.
Default PhotoQt works in full mode but in the settings you can choose windowed mode.
Installation latest version into Linux Mint:
sudo apt-add-repository ppa:lumas/photoqt sudo apt update sudo apt install -y photoqt
If you are running Linux Mint 17.x:
Use the guide from the official website