Help me get some irregular screenshots on Mac.

[Jone2473]

I usually need to get some freehand screenshots on my Mac for my project ,but the Mac system only can get the regular area .So I think here is someone else can recommend some another way doing this or a software which can do this on Mac . Thank you .By the way , if you have  a  soft ,  better give me the download url .
Thank you very much!!

[Renegade]

Irregular? I think you'll need to do that in an image editing program. I've never seen any image that's not a rectangle or square. Contents? Sure. Basic image format? No.

You can try the GIMP. That should let you do what you're looking for.

[Curt]

Shortcuts

    Command-Shift-3: Take a screenshot of the screen, and save it as a file on the desktop
    Command-Shift-4, then select an area: Take a screenshot of an area and save it as a file on the desktop
    Command-Shift-4, then space, then click a window: Take a screenshot of a window and save it as a file on the desktop
    Command-Control-Shift-3: Take a screenshot of the screen, and save it to the clipboard
    Command-Control-Shift-4, then select an area: Take a screenshot of an area and save it to the clipboard
    Command-Control-Shift-4, then space, then click a window: Take a screenshot of a window and save it to the clipboard

In Leopard and later, the following keys can be held down while selecting an area (via Command-Shift-4 or Command-Control-Shift-4):

    Space, to lock the size of the selected region and instead move it when the mouse moves
    Shift, to resize only one edge of the selected region
    Option, to resize the selected region with its center as the anchor point


Formats

Different versions of Mac OS X have different formats for screenshots.

    Mac OS X 10.2 (Jaguar): jpg
    Mac OS X 10.3 (Panther): pdf
    Mac OS X 10.4 (Tiger) and later: png

In Mac OS X 10.4 and later, the default screenshot format can be changed, by opening Terminal (located at /Applications/Utilities/Terminal) and typing in:

• defaults write com.apple.screencapture type image_format
• killall SystemUIServer

Where image_format is one of jpg, tiff, pdf, png, bmp or pict (among others). If you omit the second line, you will need to log out and in again for the change to take effect.

[Yancy2011]

The way of curt is very detailed , but I think I can give you my method to do this by a software on Mac ,the Mac Screenshot Capture , ( macscreenshots.com/screenshotcapture_mac.html) .With it, you can edit your screen snaps as you like , and you can capture the freehand region on Mac .
Hope to be useful to you ,Good luck for your project!!