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Two-point correction, Background correction, Bad pixel correction – ALLIED Vision Technologies Goldeye P-032 SWIR User Manual

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Image processing

Goldeye Technical Manual V2.5.0

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For fast access, all available correction data (e.g. reference images for the two-
point correction and bad pixel correction control data) are copied from the non-
volatile flash memory onto a correction data memory (SDRAM) when starting
the camera. From this point the correction data is sequentially shifted through
the correction data pipeline. The image data from the camera head is shifted
through the correction modules in parallel to the correction data. If a module
needs correction data, it is fed from a tap in the correction data pipeline to the
module. A module can also write back modified correction data to the pipeline.

The main correction modules are in detail:

Two-point correction

Background correction

Bad pixel correction

Two-point correction

With help of the two-point correction (and also gain offset correction), the nor-
mally distinctive underground structure of the image sensor can be equalized.
The gain and the offset for each pixel of the input image can be adapted to the
set values on the basis of two reference images so that, in the optimum case, no
image structure is discernible.

Background correction

With this module you can correct the live image with a previously recorded dark
image. This image is subtracted from the two-point corrected image data to
reduce the remaining fixed pattern noise.

Bad pixel correction

The bad pixel correction uses up to six non-false neighbor pixels to determine
an interpolated value from the neighboring pixels that replaces the bad pixel.
In this way, the image appears without disturbing hot or cold pixels.

Note

Each module can have various parameters that control the
operation mode.

In the

Figure 21: Data processing: Goldeye xy-...

on page 55

and within the text of this manual, these parameters are
always marked by

Courier bold font in order to high-

lighting them to be parameters (or commands) adjustable via
the serial interface.

This manual is related to the following products: