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ANALOGUE - a signal that stimulates sound or vision by electrical analogy e.g. variations in voltage producing corresponding variations in brightness or vice versa.
BINARY - counting system using just two digits, 0 and 1, or black or white in imaging terms.
BIT - short for Binary Digit; a single number having having the value 0 or 1. Eight bits make 1 Byte.
BYTE - standard unit of binary data storage in memory or disc files. Each Byte contains 8 Bits, each Byte has 256 possible values (28).
CCD - Charged Coupled Device, a solid state image pick-up device or sensor that produces an output analogous to the amount of light striking each of it's picture elements.
CD-ROM - A form of compact disc used for storing digital data of all types.
CMOS - Complementary Metal Oxide Semiconductor. The second of the most commonly used types of solid state image pick-up sensors found in todays digital cameras. The CMOS sensors are less sensitive than their CCD counterparts and also consume less power. They are cheaper than CCD sensors.
COMPATIBLE MEMORY TYPE(S) - refers to the type of memory cards a camera uses to store images on. Most cameras except just one type of memory card but many will accept multiple formats.
COMPRESSION - a digital process allowing data to be stored or transmitted using less than the normal number of bits. The common form of data compression being the JPEG format.
DIGITAL ZOOM - known also as simulated zoom. Digital zoom works by taking a small portion of an image and enlarging it using interpolation software to give the effect of an optical zoom. However due to having no moving parts to physically get closer to the subject digital zooms in their nature are low quality and limited.
DIGITIZE - to convert into digital form. This process involves sampling the the analogue signal, giving it a numerical value and then coding this number in binary form. For example a digital photograph or image is made up of grid points. There is no continuous variation of colour or brightness. Each point on the grid has a specific value. Digital images are recorded as data, not as a signal. |