It's easy to operate. Please follow the steps below.
Step 1 Open Microsoft PowerPoint 2010, click Insert - Picture
Step 2 Click the picture, click Picture Tools - Format - Background Removal
Step 3 Under Background Removal, click Make Areas to Keep to indecate which parts of the picture you don't want to automatically removed.
Step 4 Click Keep Changes in the Close group, you will get what you want.