CHEETAH Hardware User’s Manual
Imperx, Inc.
Rev 1.7
6421 Congress Ave.
8/26/2016
Boca Raton, FL 33487
+1 (561) 989-0006
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of 8 pixels. In normal operation, the AOI defines the number of columns and rows
output. However, subsampling and averaging modes can be applied to the AOI
reducing the number of rows and columns output even further. Using the AOI
function and subsampling / averaging modes will have the effect of increasing the
camera frame rate. The maximum horizontal window size (H) and the vertical
window size (V) are determined by image full resolution (For example, C5180: 5180
x 5180 or C4181: 4096 x 4096).
Figure 12:
Horizontal and vertical window positioning
Note:
Color version
users – when AOI is enabled, for proper color
reconstruction and WB ‘Offset X’ and ‘Offset Y’ must be an even number.
2.3.3 Factors Impacting Frame Rate
The camera frame rate depends upon a number of variables including the exposure
time, number of rows and columns in the AOI, the amount of decimation within the
image and the bandwidth of the output interface.
AOI size:
The camera frame rate will increase by decreasing either the number of
columns or number of rows readout. Changing the number of rows readout will
result in the largest change in frame rate.
Exposure Time:
In free-running mode, the camera overlaps the exposure time and
image readout. In trigger mode, the exposure and readout time need not overlap and
long exposure times will decrease frame rate.