SVS-Vistek eco4050, Manual

Page: 61 / 138

SVS-VISTEK
Feature-Set 61
7.2.7 Defect Pixel Correction
Defect Pixel Correction interpolates information from neighboring pixels
to compensate for defect pixels or clusters (cluster may have up to five
defect pixels).
All image sensor have defect pixels in a lesser or greater extent. The
number of defects determines the quality grade and the value of all
sensors integrated by SVS-VISTEK.
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.
Under challenging conditions or high temperature environments
additional defect pixels can may appear. These can be corrected.
> A factory created defect map (SVS map), defying known defects, is
stored in the camera...
>
A custom defect map can be created by the user. A simple txt file with
coordinates has to be created. The user must locate the pixel defects
manually.
> The txt file can be uploaded into the camera. Beware of possible
Offset!
>
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 pixels or
clusters and reconstructs the expected value by interpolating neighboring
pixels that. 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.
Figure 39: Illustration of a defect pixel