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32  Camera Performance and Features Linea ML Color Cameras
Parallax Correction: Using the Camera at Non-Perpendicular Angles
to the Object
See Camera Control Category in Appendix A for GenICam features associated with this section and
how to use them.
Relevant Features:
imageDistortionCorrectionMode , imageDistortionCorrectionAlgorithm ,
imageDistortionCorrectionLineSelector , imageDistortionParallaxCorrectionPixelStretch
When using a camera at an angle to the objects surface, the object pixel size for the red, green
and blue pixel arrays are slightly different. This is due to parallax. If the camera angle and the lens
angular field of view are sufficiently large, this may cause color artifacts at the extremities of the
image. The color camera includes a Parallax feature that can correct these color artifacts.
Figure 15: Camera Angle Creates Parallax
Notes:
 This feature will be most useful when processing RGB image formats using 8K cameras with
long focal length lenses.
 Parallax correction of the individual colors cannot be performed due to the row summing in
the sensor. Therefore, at high angles, a degradation in MTF at the end pixels may occur.
 Selection of the color to adjust is dependent on positive or negative angle. It is not sensitive
to scan direction.
 The stretch value for green is always half that of the stretch value for blue or red.
Projected Color
Filters @
Object Plane
Higher
Magnification
Lower
Magnification
‘Stretch’ Lower Magnification
Blue Image by Progressively
Adding Pixels to Achieve
Higher Magnification Equivalent
8192
Pixels
8192
Pixels
8185
Pixels
Parallax Example
8K Camera
Camera at 45 degrees
80mm lens
10um Object Pixel
Camera
Angle Where
Red is
‘Stretched’
Camera
Angle Where
Blue is
‘Stretched’