Reconstruction of full color high resolution images from a low resolution color image, and a high resolution monochrome image
Formerly, in the early 1930s, the first electronic devices developed for capturing images were pickup tubes. Solid-state imaging devices began to emerge in the 1960s. A major advance in solid-state imagers came in 1970 with the invention of the charge coupled device. Because CCDs use silicon technology, they can be mass-produced inexpensively like other silicon integrated circuits. CCDs are also much more compact and rugged than vacuum tube devices, and they have less noise, higher sensitivity and greater dynamic range. Now, CCDs have completely replaced the pickup tubes once used in consumer video cameras. The CCD has also become the device of choice for a wide variety of applications ranging from document scanners to cameras for astronomical telescopes.
A charged-coupicd device is an array of metal-oxide-semiconductor capacitors designed to translate an incident pattern of photons into a discrete analog signal preparatory to digitization. When the MOS capacitors are properly clocked, they move stored charges along from one capacitor to the next in a controlled manner, somewhat like a bucket brigade. The CCD really performs two functions: First it converts photons into electrical charge (electrons or holes), and then it temporarily stores and moves this 'image-wise' charge around so it can be read in some combination of parallel and serial readout modes. At the output of the device, the signal charge is converted to voltage. Further downstream, additional electronic devices do the digitizing.