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Color depth is a computer graphics term describing the number
of bits used to represent the color of a single pixel in a
bitmapped image or video frame buffer. This concept is also
known as bits per pixel (bpp), particularly when specified along
with the number of bits used. Higher color depth gives a broader
range of distinct colors
Truecolor can frequently mimic many colors found in the real
world, producing 16.7 million distinct colors. This approaches
the level at which the human eye can distinguish colors for most
photographic images, though image manipulation, some
black-and-white images (which are restricted to 256 levels with
Truecolor) or "pure" generated images may reveal the
limitations.
24-bit Truecolor uses 8 bits to represent red, 8 bits to
represent blue and 8 bits to represent green. 28 = 256 levels of
each of these three colors can therefore be combined to give a
total of 16,777,216 mixed colors (256 × 256 × 256).
Twenty-four-bit color is referred to as "millions of colors" on
Macintosh systems. Beyond truecolor 32-bit color
In the late 1990s, some high-end graphics hardware and
scanners started to use more than 8 bits per channel, such as 12
or 16. This has never become common, as the gain in color
resolution is almost invisible – 10 bits per channel seem to be
enough to reach the absolute limits of human vision under almost
all circumstances.
However, professional-quality image manipulation software has
started to employ 16 bits per color channel for internal
storage, providing protection against accumulating rounding
errors when multiple consecutive manipulations are performed on
a picture. RGB vs CMYK
The RGB color model is an additive model in which red, green,
and blue (often used in additive light models) are combined in
various ways to reproduce other colors. The name of the model
and the abbreviation ‘RGB’ come from the three primary colors,
red, green, and blue and the technological development of
cathode ray tubes which could display color instead of a
monochrome phosphoresence (including grey scaling) such as black
and white film and television imaging. CMYK (short for cyan,
magenta, yellow, and key (Black), and often referred to as
process color or four color) is a subtractive color model, used
in color printing, also used to describe the printing process
itself. The CMYK model works by partially or entirely masking
certain colors on the typically white background (that is,
absorbing particular wavelengths of light). Such a model is
called subtractive because inks “subtract” brightness from
white. |