Does anyone know what pixel dimensions a letter-size sheet of paper would have? I am scanning in some letter-size pages, and even though I told the scanner the pages are letter size, it pays more attention to what the image quality in DPI is (I have tried 75 and 150), gives me too large an image, and then expects me to enter pixel dimensions in reducing the size. I have it down to 785 x 969 pixels, and on the screen, that looks like the size of the pages, but I won't be surprised if appearances are deceiving. I just want the scanned pages to be the same size , if printed, as the originals.

A given paper size can be assigned any number of pixels you want. It depends on what you are going to do with the file. No matter what you select in scanning, you can scale it in printing to match the paper size you are using.

Really good quality laser printer output would be 600pixels/inch (AKA ppi or dpi). Assuming that the original is the same size as the intended print out, I would never scan at less than 600---sometimes I use 1200.

I suggest you run some experiments for the specific type of thing you are scanning/printing.

The image dimensions will be a factor of page size and resolution. FYI: for document imaging a scan resolution of 200 DPI is considered the industry standard minimum. If you plan to OCR the document, a 300 DPI minimum would be better.

So if you're scanning standard U.S. Letter of 8.5x11, resolution should be 8.5 x 200 = 1,700 or 8.5 x 300 = 2,550 pixels wide by 11 x 200 = 2,200 or 11 x 300 = 3,300 pixels tall.

Display resolution and image resolution are two completely different things.