Control image: Click image and Drag it to pan right, left, up or down!

Zoom: If gray bar with + & - appears below image, Click on the + (in) and - (out) buttons.

Alternate Zoom: If NO gray bar with + & - appears below image, then 

                            Click image, Release, then

                            Press & Hold Shift(in) or Control(out) on keyboard, then

                            Click image to zoom.