I want to use a digital camera image to have printed on something from a company online. Their guidelines say that as long as the image is scanned at at least 300 dpi, it will print OK. However, I have the image already on my computer and I don't know the resolution of it. How can I find that out? The photo programs I have don't tell me the dpi, and right clicking on it and choosing "properties" doesn't help either.