I have a Microtek scanner and Scanwiz twain32 software and adobe PS 5.01. For some reason(this just started) when I scan an image, that portion of the scan that does not contain the image is black. Which when printing uses up a lot of ink unless I crop first. How do I get the "background" outside the image to be white or transparent? Also how can I make the Scanwiz default to 256 shades of gray and not millions of colors?