CHEETAH Hardware User’s Manual
Imperx, Inc.
Rev. 6.2
6421 Congress Ave.
7/7/2015
Boca Raton, FL 33487
+1 (561) 989-0006
53 of 152
Figure 2.8b: WDR mode enabled
To extend the dynamic range of the camera, the output is partitioned into several
user defined zones. In the simplest case, the user partitions the output into one region
for dark pixel data in which pixels integrate for the full exposure period and another
region for bright pixel data in which pixels integrate for only a small portion of the
total exposure period. Table 2.6a demonstrates one such partitioning. Assuming 10-
bit digitization, Dark pixel data have values from 0 to 512 counts (50% of the
output) and Bright pixel data values range from 513 to 1024 counts (51% to 100% of
the output). The user must keep in mind, however, that Bright pixel data was
captured with a much shorter exposure period. For example, suppose the user selects
a Bright pixel exposure period which is 10% of the overall exposure period. In this
case, a pixel with a value of 612 counts resides in the Bright pixel data partition and
represents 100 counts (612 – 512) taken with an exposure that is 10% of the total
exposure. These 100 counts of signal then were collected with 1/10
th
the exposure
time of the Dark pixels and therefore these 100 counts are 10x brighter than 100
counts of signal collected in the Dark pixel partition.
Percentage
of Output
Pixel Data
100%
Bright Pixel
Data
