Which tool to crop a portion of the screen?

On Gnome Shell (17.10+)

To use the built-in gnome-screenshot capability (by default):

• Ctrl+PrintScreen to copy a screenshot of the whole desktop.

• Ctrl+Alt+PrintScreen to copy a screenshot of the current active window.

• Ctrl+Shift+PrintScreen to copy a screenshot of an area you select with your mouse.

• PrintScreen to save a screenshot of the whole desktop at /home/user/Pictures.

• Alt+PrintScreen to save a screenshot of the current active window at /home/user/Pictures.

• Shift+PrintScreen to save a screenshot of an area you select with your mouse at /home/user/Pictures.

On Unity

To use the built-in Screenshot capability:

• PrintScreen to copy a screenshot of the whole desktop.
• Alt+PrintScreen to copy a screenshot of the current active window.
• Shift+PrintScreen to copy a screenshot of an area you select with your mouse.

Applications > Accessories > Take Screenshot... Select area to grab.

Method 1:

• Go to Applications > Accessories > Take Screenshot

  

• Now you can select the portion of a screen.

Method 2:

Update: Shutter got removed from Debian/*Ubuntu repos because it uses deprecated Perl modules.

• If you use shutter, Applications > Accessories > Shutter

• Open it and click selection in the top of the screen.

  

• Now you can select the portion of the screen.

Method 3:

• Take a screenshot of a whole desktop by hitting printscreen.
• Open the screenshot using GIMP.
• Press SHIFT + C to crop the portion.

Well if you mean pressing the Print Screen button and then cropping with a console tool, then you have mogrify to do that (by installing the imagemagick tools)

If you want to take a picture of a certain windows, select the window a leave Alt pressed while pressing the Print Screen key.

Using Compiz, you can zoom to an area using the Super key and scrolling inwards, then Print Screen.

In KDE you have ksnapshot which gives many abilities, one including taking a snapshot of a region.

Shutter is also a great capturing application and it can crop a portion of the screen automatically.

With imagemagick installed, you can type:

import filename.png

at the command prompt. It will give you a cross-hairs you can use to draw a rectangle on the screen which it will then capture.

(filename.png can be any graphics format.)

Flameshot

I know this is a 10 year old question but I didn't like any of the options posted. I really like Flameshot. It's a one-stop shop with nice keyboard shortcuts. Simply apt install flameshot.

Shutter got removed from Debian/*buntu repos because it uses deprecated Perl modules. Gnome- and Mate-screenshot are too basic.

scrot

sudo apt-get install scrot

scrot (SCReen shOT) is a simple commandline screen capture utility that uses imlib2 to grab and save images. Multiple image formats are supported through imlib2's dynamic saver modules.

Run: scrot -s

Just wanted to add that you can now type shift+printscreen to select an area to print.

If you want to use GIMP to capture only part of a shot of the display screen, then use File - Acquire - Screenshot - Select region to grab - Snap. Left-click on the screen, hold button down, drag to form a rectangle, and release the mouse button to capture an image of the selected portion of the screen.

Note that different versions of GIMP use different command menu sequences, e.g. "Acquire" may be labelled "Create".