The most common way to turn your rectangular picture into a perfect circle is to create a circle shape and fill it with an image. I came up with a quicker method earlier this week. How did I not discover this before?! This method works in PowerPoint 2010 and 2013.
Insert your picture onto your slide. (Insert | Picture) Select the picture. On the Picture Tools Format tab, click the bottom of the Crop button and choose Aspect Ratio, 1:1. This crops your image to a perfect square.
Now change the perfect square to a perfect circle by clicking the bottom of the Crop button again. This time use Crop to Shape and choose the oval shape. Because the aspect ratio is 1:1, the oval is actually a circle.
Sneaky little Cropping refinements:
If the image isn’t positioned correctly, you can easily move it inside the circle shape – or within any crop, for that matter. Click the top of the Crop button to activate crop mode, then just drag the picture around within the frame. If the edge of your picture is right at the edge of the crop frame like it is in this example, press Shift while you drag. This keeps the picture from becoming mis-positioned within the frame, leaving you with blank pixels near an edge.
If you want to resize the picture within the frame, activate cropping mode and drag the corner of the picture to resize it. Make sure you grab the white circle at a corner of the picture and not the black crop handles, which control the cropped frame itself. Also, even though you’re dragging a corner, be sure to press Shift when resizing a picture so you don’t distort the image.
(Big thank you to Julie Terberg (terbergdesign.com) for letting me use her polar bear picture.)