Dalsa Linea SWIR GigE Series User Manual page 57

Ingaas line scan camera

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Example User Defective Pixel Map XML File

The following example shows the required components of the defective pixel map file. Each bad

pixel position (relative to the image origin, which is the upper left corner), must be identified by

the XML statement:

<DefectivePixel OffsetX="

The pixel format (8 or 12-bit) is handled transparently, thus requires no special consideration by

the user. This example XML listing has four "bad" pixels identified.

<?xml version="1.0" encoding="UTF-8" ?>

<!–-Example User Defective Pixel Map -- >

<!-- maximum 512 coordinates -- >

<!–-filename: ExampleBadPixels.xml

</Coordinates>

Image Response Uniformity & Flat Field Calibration

The Flat Field Correction function (FFC) consists of using two coefficients per pixel to correct the

gain and offset of the corresponding pixel. These corrections compensate for Photo-Response Non-

Uniformity (PRNU) and Fixed Pattern Noise (FPN) unique to each camera sensor and the lens

used.

Related Features: flatfieldCalibrationFPN, flatfieldCalibrationPRNU,

flatfieldCorrectionCalibrationAlgorithm, flatfieldCalibrationTarget

It is common to find an image has a lower response at the edges of the camera's field of view

compared to its center. This is typically the result of a combination of lens vignetting (cos4th)

roll-off and the beam structure of the illumination source. Using a more diffused light may reduce

the roll-off effect. However, if decreasing the lens aperture improves the edge roll-off, then barrel

vignetting (a shadow cast on the sensor by the focus helical or extension tubes) may also be

present.

The camera can compensate for edge roll-off and other optical non-uniformities by activating Flat

Field Correction after the calibration procedure acquires correction coefficients.

Linea SWIR GigE Series Camera

number

" OffsetY="0"/>

-- >

Operational Reference

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