---
title: "Creating a black-reference (DSNU)"
slug: "create-a-black-reference-dsnu"
updated: 2024-10-10T12:58:18Z
published: 2024-10-10T12:58:18Z
canonical: "docs-linescan.alliedvision.com/create-a-black-reference-dsnu"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs-linescan.alliedvision.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Create a black-reference (DSNU)

Create a black-reference with DSNU.

| 1. Switch off the illumination. 2. Cover the lens with a black or dark piece of cardboard or plastic. No light may reach the sensor. |  |
| --- | --- |
| 1. In the *menu bar* navigate to *Tools* → *Calibration*. 2. Click **Generate DSNU Reference**. | ![](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/image-1685541400924.png) |
| The *Generate DSNU Reference* wizard opens. 1. Click **Acquire image** to generate the DSNU directly from the camera **or** click **Load from Disk** to load an image from the hard drive. NOTE: Load from Disk Make sure that the image has been taken with active image calibration mode by using the wizard. The raw image and the line plot of the image is displayed. Send the calculated DSNU to the camera: 1. Select **LUT 1** or **LUT 2**. 2. Click **Send data to camera**. | ![](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/image-1685541280386.png) |
| 1. In the Configuration window navigate to *Camera Image Calibration* → *DSNU/PRNU*. 2. Make sure that DSNU is enabled. | ![getting-started-image-20n4f0fx](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/getting-started-image-20n4f0fx.png) |

Dark signal non-uniformity