Dalsa Linea2 5GigE, Руководство пользователя

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Linea2 5GigE Series Camera Camera Performance and Features • 47
Parallax Correction: Using the Camera at Non-
Perpendicular Angles to the Object
When using a camera at an angle to the objects surface, the object pixel size for the red, green
and blue (and NIR) 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 Correction Pixel Stretch feature that
can correct color artifacts. The blue or NIR row can be used as the parallax correction reference
row according to the pixel format (BGR or BGRA).
Figure 38: Camera Angle Creates Parallax
Notes:
• This feature will be most useful when processing RGB image formats using 4K 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
‘Stretch Lower Magnification
Blue Image by Progressively
Adding Pixels to Achieve
Higher Magnification Equivalent
4190
Pixels
Parallax Example
4 k Camera
Camera at 45 degrees
Camera Angle
Where Blue
(or NIR) is
‘Stretched
N
IR
Camera Angle
Where Red is
‘Stretched
4196
Pixels Lower
Magnification