What Is A Non-Uniformity Correction (Nuc) - FLIR A6000 Series User Manual

NOTE: It is possible for a bad pixel to fail more than one category, so the total bad pixels may be less
than the sum of each category. "Factory" bad pixels are those that were determined to be bad during
camera production testing.

5.5.5 What is a Non-Uniformity Correction (NUC)?

Non-Uniformity Correction (NUC) refers the process by which the camera electronics correct for the
differences in the pixel-to-pixel response for each individual pixel in the detector array. The camera
can create (or allow for the user to load) a Non-Uniformity Correction (NUC) table which consists of a
unique gain and offset coefficient and a bad pixel indicator for each pixel. The table is then applied in
the digital processing pipeline as shown in Figure 4-12. The result is corrected data where each pixel
responds consistently across the detector input range creating a uniform image.
x
Detector
Analog
Gain/Offset
Figure 4-12: Digital Process Showing NUC Table Application
To create the NUC table, the camera images either one or two uniform temperature sources. The
source can be an external source provided by the user or the camera's internal NUC flag which is
basically a shutter the camera places in front of the detector. If the source is external it should be
uniform and large enough to overfill the cameras field-of-view (FOV). By analyzing the pixel data from
these constant sources, the non-uniformity of the pixels can be determined and corrected. There are
two types of processes which are used to create the NUC table; Two-Point, and Offset Update.
A6000 and A8500 Series User's Manual
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14-bit A/D
Bad Pixel
x +
Replacement
Algorithm
NUC Table
5 –Camera Controller
Uncorrected Data
Corrected Data
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