The Lasso Select tool comes in handy when selecting a part of an image that's not perfectly rectangular or elliptical. The Lasso Select tool can be used to draw a free-form border around a selected object within an image.
How to Use the Lasso¶
Select the Lasso Select from the Tools menu.
Position the cursor on the edge of the element that you want to select, and click and hold the mouse button.
Trace around the element while continuing to not release the mouse button while capturing only what you want to retain in your selection. While you trace, a dotted line forms that follows the movement of your mouse. Continue to trace the selection and return to the starting point to close the loop.
Release the mouse button and Pinta will finish the selection. If you didn't trace fully back to your start point, a straight line from your endpoint to your startpoint is generated.