Basics of photo scanning
Scanners typically read red-green-blue color (RGB) data from the array. This data is then processed with some proprietary algorithm to correct for different exposure conditions, and sent to the computer via the device’s input/output interface (usually USB, previous to which was SCSI or bidirectional parallel port in older units). Color depth varies depending on the scanning array characteristics, but is usually at least 24 bits. High quality models have 36-48 bits of color depth. Another qualifying parameter for a scanner is its resolution, measured in pixels per inch (ppi), sometimes more accurately referred to as Samples per inch (spi). Instead […]