pciGrabber-4x4
118
PHYTEC Messtechnik GmbH 2008 L-720e_0
RGB16
has a reduced resolution of the color. This for-
mat requires five bit for the blue and red channel, and
the green channel has 6-bits. The color depth is 65.536
(
65536
2
2
2
6
5
5
=
⋅
⋅
). One pixel needs 16-bits = 1 word.
In
Figure 49
the partitioning into three color channels
of the word is depicted. The color information is
arranged „left justified“; the lower bits are omitted, so
that the color depth is reduced. The color depth of the
green channel is twice of the two other channels. The
RGB16-format corresponds to the color system of
graphic cards with 65.535 colors.
RGB15
: The division corresponds to the RGB16-
system, except that all color channels have the same
color depth (each 5-bit=32 levels). Therefore we yield
32.818 colors. Altogether only 15-bits are necessary,
so that the upper bit of a word is a stuffing bit and has
the value 0 (see Figure 49).
YCrCb
: In this format we find grey values and color
information separately. The parameter Y describes the
brightness of the pixel (grey value) and the parameter
(Cr,Cb) provides the color information. (Cr,Cb) can be
considered as a vector of the chromatic circle. The tone
of the color corresponds to the angle of the pointer, the
saturation is presented by the absolute value of the
vector. This format is applied for graphic cards with
YCrCb-systems with separate processing of brightness
and color value - which is very compact for the storage
of images in memories.
YUY2:
This format corresponds to the format YCrCb
4:2:2.
