once you have the picture how long you want it to be , Move your timeline cursor to the beginning of the pic. Go to the effects control window. click on motion and drop down the menu. (motion is a fixed effect so it is already there.) Click the "toggle animation" button next to SCALE. the scale is basically how big the picture is but you can use it as a zoom. It is preset on 100. If you change it to a smaller number, the picture will shrink and vice versa. Once you have clicked the animation button, move your timeline cursor to the end of the pic. Now go back to the effects control window and change the scale to a larger number than 100. you can click on the 100 and type in a new number or you can simply hold you mouse over the number, click it, and slide it to the left. Then just simply rerender the picture and your good to go. You can also try the 3d channel effect but this is much easier i think.