While what follows may seem elementary to experienced scanner operators, for others it will be a welcomed review. That's because most scanners, especially flatbeds, are so simple to operate that we assume we know more than we do. That is, until we run into a problem and start playing with the settings. I have found that learning the basics goes a very long way in helping you get the best result on the first scan. Pixels, samples and bits Think of a digital image as a matrix or bitmap of adjacent pixels.
Pixels are small squares of solid black, white, grays or color.
A sample is a reading, and the number of samples recorded within a given distance is the resolution. Scanning resolution is normally specified in pixels per inch. The size of the pixels changes according to the resolution. You determine the physical size of an image by dividing the number of pixels by the resolution. Bit depth, also known as pixel depth, defines how many tones or colors every pixel in a bitmap can have.