BOBCAT HD-SDI
Hardware User’s Manual
Imperx, Inc.
Rev. 1.4
6421 Congress Ave.
6/2/2014
Boca Raton, FL 33487
+1 (561) 989-0006
57 of 175
Input signal
O
ut
put
s
ignal
Original TF
Modified TF
Figure 2.15 – Custom LUT.
2.14.
DEFECTIVE PIXEL CORRECTION
A CCD imager is composed of a two-dimensional array of light sensitive pixels. In
general, the majority of the pixels have similar sensitivity. Unfortunately, there are
some pixels which sensitivity deviates from the average pixel sensitivity. A defective
pixel is defined as a pixel whose response deviates by more than 15% from the
average response. In extreme cases these pixels can be stuck ‘black’ or stuck ‘white’
and are non-responsive to light. There are two major types of pixel defects –
“Defective” and “Hot”.
1.
”
Defective
” – these are pixels which sensitivity deviates more than 15% due to
fluctuations in the CCD manufacturing process. Two type of defective pixels are
possible:
a.
“
DARK
” is defined as a pixel, whose sensitivity is lower than the sensitivity of
the adjacent pixels. In some cases this pixel will have no response (completely
dark).
b.
“
BRIGHT
” is defined as a pixel, whose sensitivity is higher than the
sensitivity of the adjacent pixels. In some cases this pixel will have full
response (completely bright).
2.
“
Hot
” – these are pixel, which in normal camera operation behaves as normal
pixel (the sensitivity is equal to the one of the adjacent pixels), but during long
time integration behaves as a high intensity bright pixel. In some cases this pixel
will have full response (completely bright).