Camera shots aren't always perfectly framed. When you examine them, you might find that they're off-center or contain extraneous objects on one or more edges, for example. You can correct these photos with the Crop tool, selecting a rectangular portion that you want to keep while trimming away all material outside the selected area. You can crop any image to match a common photo paper size or create a custom-sized image.
Open a picture for editing, click the Basic Fixes tab, and click the Crop button.
Click a radio button on the Crop Picture panel to set the image's dimensions.
Click and drag in the picture to set the crop area. (If you selected any option other than Manual in Step 2, the dragged area will maintain constant proportions that correspond to the selected dimensions.)
Optional: To change the size of the selection rectangle, drag one of its edges or corners. To change the position of the selection rectangle, click anywhere in its center and drag it to a new location. To switch from a portrait to a landscape selection rectangle, click the Rotate button. To see what the selected area will look like when cropped, click the Preview button.
When you're satisfied with the selection, click Apply.
The cropped image replaces the original in Edit View and in the Picture Library.
If you decide that you'd like to restore the original, open it for editing again and click the Undo Crop button at the bottom of the Edit panel.