To make your image file size smaller you need to use a photo software of some kind, for example I use MS Image composer. Whatever program you choose to use should have scaling, so if at 100% size the image will be larger than the screen size. Once you get the image to display at 100% and its fitting in the screen, then you can upload it.
If all else fails, send me a PM, and I can resize the image for you.
JW