How to perform PRNU and DSNU

To correct for PRNU, the camera’s internal correction circuit captures one or several lines of data
under non-saturated illuminated conditions (not more than 80% of maximum - recommend level is
half of maximum), and the average across the line is calculated. Based on this average, coefficients
are then generated for each individual pixel. The coefficient has the function of multiplying the
pixel output with factor greater or less than 1. These coefficients are stored in a non-volatile
memory, and are therefore maintained after power down.

Setup setting:

a) Set GevGVCPPendingAck to True

b) To capture white paper with flat light source.
c) De-focus with lens to avoid wrong correction by small difference on the white paper.
d) Perform Pixel gain calibration (PRNU)

Is a variation between pixels in the dark areas generated by the sensor. If the line rate is slowed or a long exposure time is set, the dark current in the sensor may change and the state of the DSNU may change.


a) Set GevGVCPPendingAck to True
b) Perform black level correction(DSNU) with lens cap on


When calibrating you should perform the DSNU first and then the PRNU. When calibrating for For SW-4000/8000 series, camera might freeze a couple of minutes when doing the calibration.

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  • 0
    Harry Hashimoto

    Dear all:

    Additional notes:

    a) If you execute both PRNU and DSNU, DSNU correction should be first, followed by PRNU because PRNU is calibrated on DSNU correction result.

    b) For SW-4000/8000 series, PRNU would spend more than minutes.


  • 0
    Roger Lin

    Is 50% light level correct for PRNU?

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