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CMOS
Complementary Metal Oxide Semiconductor (CMOS) can perform signal
amplication on a per-pixel basis. Significant current flows only during the
switching operation. Therefore a CMOS image sensor can scan data rapidly,
sustain high-speed operation and consume less energy. Recent technological
and production improvements in digital imaging systems are making CMOS more
and more competitive in terms of image quality and cost.
Color Temperature
The numerical expression of the tone of the light, produced by a light source. The
standard unit for color temperature is degrees Kelvin (K). The sunny daylight
used as a standard near 5600 K. Low color temperature implies warmer more
yellow/red light while high color temperature implies a colder more blue light. The
typical color temperature of Tungsten light is 3200 K grade, a personal computer
is 9300 K.
Exposure.
The amount of light reaching the image sensor’s surface. The exposure is
controlled by the combination of aperture value and shutter speed.
EV
Exposure Value (EV) is a numerical value that expresses the amount of light for a
given exposure, and depends on brightness of the photographic subject and
sensitivity of the film. If a photographic subject is bright, then this numerical value
will be large, and if the subject is dark then this numerical value will be small. If
two-times of light reaches the film surface then the difference in exposure value
will be +1, and if the amount of light is reduced by half, the exposure value
changes by -1.
Histogram
The histogram function is a graphic representation of how bright and dark pixels
are distributed in an image. The histogram function enables a precise check on
the exposure of the photo.
ISO Sensitivity
ISO（ International Organization for Standardization） ; refers to the number
assigned to each silver halide film, which indicates film speed or the film's relative
sensitivity to light, the higher the number, the greater photosensitivity and vice
versa. Digital cameras also use standard ISO sensitivity ratings like silver halide
films.
JPEG
Joint Photographic Experts Group has established a standard method for
compressing and decompressing the digitized images. If the rate of compression
is high the file size will be small but picture quality will be decreased.
