SVS-Vistek SHR 10GigE, Руководство пользователя, Страница: 51 / 103

7. Run camera with same lighting to see corrected image.
5.2.3 Defect pixel correction
All image sensor have defect pixels in a lesser or greater extent. Type and num-
ber of defects determine the quality grade (quality classification) of the sensor.
Defect Pixel Correction is using information from neighboring pixels to com-
pensate for defect pixels or defect pixel clusters (cluster may have up to five
defect pixels).
Defect Pixels either be dark pixels, i.e. that don’t collect any light, or bright pixels
(hot pixel) that always are outputting a bright signal.
The amount of hot pixels is proportional to exposure time and temperature of the
sensor.
By default, all known defect pixels or clusters are corrected by SVS-VISTEK as a
factory default.
Under challenging conditions or high temperature environments defect pixel beha-
viour might change. This can be corrected.
l
A factory created defect map (SVS map), defying known defects, is stored in
the camera.
l
A custom defect map can be created by the user. A simple *.txt file with
coordinates must be created. The user must locate the pixel defects manu-
ally.
l
The *.txt file can be uploaded into the camera. Beware of possible Offset!
l
Defect maps can be switched off to show all default defects, and switched
back on to improve image quality.
Unlike shading correction, defect pixel correction suppresses single pixels or
clusters and reconstructs the expected value by interpolating neighboring pixel
values. The standard interpolation algorithm uses the pixel to the left or to the right
of the defect. This simple algorithm prevents high runtime losses.
More sophisticated algorithms can be used by software.
5 Feature description 51