Color Creation In The A400Kc - Basler A400K User Manual

Basic Operation and Features

3.11 Color Creation in the A400kc

The CMOS sensor used in the A400kc is equipped with an additive color separation filter known
as a Bayer filter. With the Bayer filter, each individual pixel is covered by a micro-lens which lets
light of only one color strike the pixel. The pattern of the Bayer filter used in the A400kc is shown
in Figure 3-17. As the figure illustrates, within each block of four pixels, one pixel sees only red
light, one sees only blue light, and two pixels see only green light. (This combination mimics the
human eye's sensitivity to color.)
B
G
B
G
B
G
B
G
B
G
Pixel
1, 1
B
G
Figure 3-17: Bayer Filter Pattern on the A400kc
A single value is transmitted out of the camera for each pixel in a captured image. If you want to
get full RGB color information for a given pixel in the image, you must perform a color interpolation
using the information from the surrounding pixels. Some frame grabbers are capable of
performing the color interpolation and many algorithms are available for performing the
interpolation in your host PC.
3-36
DRAFT
G B G B
R G R G
G B G B
R G R G
G B G B
R G R G
G B G B
R G R G
G B G B
R G R G
G B G B
R G R G
B G B G
G R G R
B G B G
G R G R
B G B G
G R G R
B G B G
G R G R
B G B G
G R G R
B G B G
G R G R
Horizontal Shift
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