FLIR Camera Adjustments
102-PS242-100-01
Rev110
June 2014
Page 22 of 28
Manual
The “manual” algorithm performs a linear transformation from 14-bit to 8-bit, with slope based solely on
a specified contrast value and offset based solely on a specified brightness value as shown below:
m = specified contrast / 64
b = 127 – (brightness)*m.
Auto Bright
The auto-bright algorithm is identical to the “manual” algorithm except that brightness value is
automatically and dynamically updated to equal array mean. In other words, the array mean is
automatically mapped to an 8-bit value of 127.
Once Bright
The “once bright” algorithm is identical to the “auto-bright” algorithm except that the offset of the linear
transformation, b, is computed only at the time the algorithm is selected and is not dynamically updated.
It is computed as
b = 127 – (frame mean – brightness bias)*m,
where brightness bias is a user-specified parameter.
2.5
Digital Data Enhancement (DDE)
The Tau 2 core provides an optional “digital-data-enhancement” (DDE) algorithm which can be used to
enhance image details and/or suppress fixed pattern noise. Two modes are available, “manual” and
“dynamic”. The descriptions of each mode are as follows:
Dynamic mode: DDE parameters are computed automatically based on scene contents. DDE
index (which supplants the spatial-threshold parameter used in the manual algorithm) is the only
controlling parameter and ranges from -20 to 100 for Tau 2.7 and later releases, with higher
values representing higher degrees of detail enhancement. If no enhancement is desired, the
value should be set to 0. Values less than 0 soften the image and filter fixed pattern noise, as
exemplified in the figures below. Values greater than 0 sharpen the details in the image. For
previous Tau 1 and Tau 2 releases, the DDE index ranged from 0 to 63, where 0 to 16 softened
the image, 17 was neutral, and 18 to 63 sharpened detail.
