gThumb is an image viewer, browser, organizer and editor for the Linux system. It is released under GNU General Public License. Using gThumb image editor, you can edit image and adjust colors,Scale and rotate images, crop images, import images from a digital camera, convert image format and browse hard disk images files.
In Ubuntu open the terminal app by searching terminal in ubuntu dash and type the below command and press the Enter key.
sudo apt-get update
Then type the below command and hit enter. Then run the below command in terminal to install gThumb image viewer and editor on Ubuntu.
sudo apt-get install gthumb
Type Y and hit enter to confirm the gThumb image viewer and editor installation. After the successful installation of gThumb image viewer and editor restart your pc. Type the below command in terminal app to start gThumb image viewer and editor.
You can also open it from Ubuntu Dash home from unity launcher. Just type gThumb in the search field. Then click gThumb image viewer to open it.