I need to make my product images have a pure white or transparent background (RGB Values of 255 or Color Code #FFFFFF) Images must be at least 1000 pixels on the longest side while making sure the item makes up at least 85% of the image frame. These are Amazon's requirements for clothing pictures and I am so far out of my element!! I am trying to download Photoshop and have not been able to (the free trial so I can see if I can even use it). Any help at all would be great. Thanks!!!