CHEETAH Hardware User’s Manual
Imperx, Inc.
Rev. 6.2
6421 Congress Ave.
7/7/2015
Boca Raton, FL 33487
+1 (561) 989-0006
38 of 152
Figure 2.1 – 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.
2.5.3 Factors Impacting Frame Rate
The camera frame rate depends upon a number of variables including the, integration
time, number of rows in the AOI, the amount of decimation within the image, the
A/D converter bit depth, the bandwidth of the output interface and whether triggered
dual video mode is enabled.
AOI size:
The camera must readout an entire image sensor row even if the AOI
function specifies a lower horizontal (fewer columns) resolution. The camera need
not readout all rows, so improvements in frame rate are possible as the number of
rows in the AOI decreases.
Exposure Time:
The camera overlaps the exposure time and image readout. If the
exposure time is increased to a value exceeding the minimum readout time, the
frame rate will be reduced accordingly.
Decimation:
The camera supports both sub-sampling and pixel averaging to reduce
the output resolution. Use of the pixel averaging feature does not increase the image
sensor frame rate, because all the pixels must be readout and averaged together.
