Photoshop offers a wealth of tools for cropping images. You can crop to an aspect ratio, use content-aware fill and many other techniques.

It only takes a few steps to change your image's background color in Photoshop. You'll just need to use the Quick Selection Tool and Quick Mask mode.

To manually crop a picture in Microsoft Word, Excel, or PowerPoint, select it, and in the Picture Format tab on the ribbon, click the top half of the split "Crop" button.