Select the image to clip by selecting the image boundary.
Enter n (New Boundary).
Enter n (No) or y (Yes) to delete the old boundary.
Enter p (Polygonal) or r (Rectangular), and then draw the new boundary on the image.
If you are drawing a polygonal boundary, you are prompted to specify consecutive vertices. To finish drawing a polygon, press Enter or right-click anywhere in the drawing area.
Tip: You can modify clipped boundaries with grips.