Digitizing requires 2 steps: sampling and quantizing. There are 4 types of scanners there is a flatbed scanner which can scan papers up to 11 x 14 inches, sheet-fed scanners which scans only letter-size papers, hand-held scanners which are portable but don’t produce high-quality images, and drum scanners which create the highest quality pictures out of the 4 different types. Bit depth refers to the number of bits in a picture which turn determines how many color values are in a picture. For example, 8 bits would allow 256 colors whereas 24 bits would allow 16,777,216 colors. The more bits in a picture, the more colors are allowed in the pictures.  There are two formats in photoshop RGB and CMYK. RGB is a little more saturated than CMYK, but CMYK is mainly used for printing. If the file is in RGB format, Red and Green makes Yellow, Green and Blue makes Cyan, and Blue and Red makes Magenta. All 3 colors in RGB create white, whereas the 4 colors of CMYK create black. There are many types of filters to use in photoshop including grayscale, monotone, duotone, and so on.