Why is there a chessboard pattern on the scaled image display when using the mvBlueFOX3-1100G / mvBlueCOUGAR-X1010G?

mvBlueFOX3, mvBlueCOUGAR

The 10 Mpixel sensor is a "real" gray scale sensors, and not, as you could expect from the chessboard pattern, a sensor with a Bayer filter. However, the electronic readout is the same as with the color models and for this reason there are four different analog gains. Depending on the scaling of the image this can be visualized like a chessboard pattern due to the aliasing effect, even if the difference between the four gain channels is supposed to be small.


Figure 1: Chessboard pattern in scaled display

The taps are organized as shown in the following figure:


Figure 2: Tap order on mvBlueFOX3-1100G / mvBlueCOUGAR-X1010G

To minimized this pattern, you can balance the sensor patterns since Firmware version This procedure works like the white balancing used with color sensors. For this reason the same terms are used (red, blue, green).

The balance reference is the "green" pixel value from the "blue-green" line of the sensor.

I.e. all gray scale values of the these "green" pixels are averaged.

With "Setting -> Base -> Camera -> GenICam -> Analog Control -> Balance Ration Selector" you can select each color to set the "Balance Ratio":

  • "Red" averages the "red" pixel values from the "red-green" line of the sensor.
  • "Green" averages the "green" pixel values from the "red-green" line of the sensor, too.
  • "Blue" averages the "blue" pixel values from the "blue-green" line of the sensor.

I.e. there are 4 average values (reference value, red value, green value, blue value). The lowest value will be unchanged, the other values are increased using each "Balance Ratio".

However by using the property "Balance White Auto" you can balance the sensor automatically:


Figure 3: wxPropView - Analog Control

After balancing, we recommend to save these settings to a UserSet.

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