Basler A102f, User Manual

Page: 47 / 170

Basic Operation & Standard Features
BASLER A102
f
3-25
DRAFT
3.8 Color Creation in the A102fc
The CCD sensor used in the
A102
fc
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 allows
light of only one color to strike the pixel. The pattern of the Bayer filter used in the
A102
fc
is shown
in Figure 3-13. 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.)
Figure 3-13: Bayer Filter Pattern on the
A102
fc
When an
A102
fc
is operating in a YUV color output mode, each pixel goes through a two step
conversion process as it exits the sensor and passes through the camera’s electronics.
In the first step of the process an interpolation algorithm is performed to get full RGB data for the
pixel. (Because each individual pixel gathers information for only one color, an interpolation must
be made from the surrounding pixels to get full RGB data for an individual pixel.)
The second step of the process is to convert the RGB information to YUV. The conversion
algorithm uses the following formulas:
Y = 0.30 R + 0.59 G + 0.11 B
U = - 0.17 R - 0.33 G + 0.50 B
V = 0.50 R - 0.41 G - 0.09 B