Working with Pictures
You have two options when sizing your graphics. If it is important to maintain proportions, which will prevent the image from looking skewed, then use the corner handles to resize the image. If you do not need to maintain the graphic's proportions, you can use the top, bottom, or side handles.
To keep the center of an object in the same place, hold down the CTRL key while dragging the mouse.
If any of the middle handles are dragged (top, bottom, right, or left), only the height and width changes, thus changing the proportion—or scale—of the picture.
Be careful; using only the sizing handle can make your pictures blurry and distorted.