Rectangle Selection Tool

* This rectangle selection tool enables you to make selections in a picture in rectangular shape.
* It is a trouble-free and a plain selection tool.
How to Launch:
- Open Gimp.
- Launch a new image file.
- Now select Rectangle Selection Tool from the toolbox.

* Shortcut for the rectangle tool is R. Click the Toolbox and then press the button R.
Tool options:

Modes - It determines the way of creating the selection, i.e. whether it will be combined with existing one, etc.
Antialiasing - It causes the boundary of the selected portion to be drawn smoother.
Feather edge - It causes the boundary of the selected portion to be blurred.
Rounded corners - It rounds the corners of the selected portion. A slider appears after enabling this option. Use it to change the radius that is used to round the corners
Expand from centre - It expands the selection, using starting point as the centre, instead of the corner. After enabling this option, the starting point is used as the centre of the selection instead of using it as a corner. This also causes the selection to extend from all sides. This option can be enabled with Shift.
Fixed - It allows you to modify the actual shape of the rectangle through four available options namely, "Aspect Ratio, Width, Height, Size". It mainly focuses on the shape of an image.
Position - It is the placement of the selection.
Size - It is the size of the selection. The actual size of the current selection. You can use it to modify the size, as well as resize it directly on the image.
Highlight - It highlights the actual selection, by darkening everything that surrounds it. Emphasizes the selected area by a surrounding mask, making the visual selection much easier.
Guides - It picks the types of guides that are shown within the selection in-order to make the selection easier. The options available under guide are "No guides, center lines, Rule of thirds, Golden sections". It adopts the photo composition rules.
Auto Shrink - It shrinks the selection to the nearest rectangular shape available on the image layer. Select a portion in the image and then apply this option, which will shrink to the nearest rectangular shape within the selection.
The algorithm for finding the best rectangle, can once do a great work, and sometimes find some strange rectangles.
Shrink merged - If it is enabled, the "Auto shrink" option will look on the actually visible image, rather than the active layer.
* Utilize the "Shift" button to switch between the options available in the toolbox.
How to Use:
- Choose a portion of an image by using the rectangle selection tool. Just drag and leave the mouse.
[Note that the selection can be made only in the rectangular shape.View the below image]

- The selected portion in the image has been picked. Now the user can make use of this portion, either by slicing (cut) the selected portion or by having a copy of the image.
- Create a new file and then paste the selected portion. It is possible to paste the selected portion from where it has been selected.

- Finally, "Save" the file.