Cheetah KAC Camera User Manual | Camera Link (CLF) Interface
October 1, 2019
Page
92
of
135
Rev 7.2
The principle of 9:1 averaging function is identical to 4:1 with a 3x3 pixel area averaged
together for black and white and a 9x9 pixel area averaged for the Bayer color pattern.
The averaging feature can be used on the full resolution image or within any area of
interest. If, for example, the area of interest is defined to be quad full HD (3840 x 2160)
and 4:1 averaging is selected, the output is 1080P (1920 x 1080); and, if 9:1 averaging is
selected the output is 720P (1280 x 720).
5.6.2 Subsampling Decimation
Subsampling reduces the number of pixels output by reducing the output frame size but
maintains the full field of view. If applied to an area of interest (AOI), the camera also
maintains the field of view.
Cheetah cameras provide a flexible subsampling capability. You define the number of
sequential pixels to read out (N) and the total number of pixels of the contiguous area
(pixels r pixels skipped) (M). The subsampling decimation factors (N and M) apply
along both rows and columns as shown (Figure 52 and Figure 53). The camera adjusts AOI
size depending on subsampling factor, averaging factor, and the presence of a color filter
array on the image sensor.
Subsampling constraints
•
The N (number of contiguous pixels read out) and M (number of pixels
in the area, which includes pixels read out and pixels skipped)
parameters are restricted to even values.
•
M must always be greater than N, and the maximum value of M is 32.
Figure 52: Monochrome subsampling with N = 2 and M = 6.
