About CCD
A computer processes information only in the form of numeric discrete units. An ordinary photograph can be considered as an analog representation of a scene , where information is recorded as a continuous stream of tones and colors. To switch between a representation of this type in a digital image, those dots must be converted to into what might be called a mosaic of pixels, where the brightness of each one matches the brightness of the corresponding analog representation area. The word pixel is short for picture element which is the smallest element of an electronic image. This can be compared, within certain limits, to grains of photographic emulsion. A pixel is basically a tiny light-sensitive metallic element, that reacts in the presence of light, generating an electrical signal. Associating a number to each of these signals, it becomes possible to reconstruct, using a computer, a digital image. To "scan" an image were used tools such as scanners, v...
