Getting Started

The documentation section helps you setting up your ALPR systems with the software and/or services provided by Q-Free. Please use the links on the right to find your product and navigate to the right section.

You can also quickly jump to the right information using the search box on the top of this page.

Q-Free Netherlands delivers all software through the “Deliveries” section on this website. With every delivery, you will receive a notification mail with direct link and description. With this link you can download the package.

For first-time users, Q-Free will set up a new account. Upon creation of a new account, you will receive a mail notification with request to activate the account. As part of this activation you will be requested to set a password.

After activation, you will have direct access to your account and all deliveries. You can see the description by clicking the “Show description” link. You can download the package by clicking the filename or the download icon in the right-most column.

Every subsequent delivery to you or your company will automatically be visible from this “Deliveries” section. In case you have forgotten your password in a later stage, you can always reset the password using the “Recover Password” button on the opening screen.

You can request to remove your account by sending a mail to

Please find below some basic rules of the thumb for achieving optimal recognition results.

  • Rotation: The camera should be mounted in such a way that in the resulting image of a single line license plate a horizontal line can be drawn which crosses both the left edge and the right edge of the license plate.
  • Vertical angle: The maximum vertical view angle of the camera is 30 degrees.
  • Horizontal angle: The maximum horizontal view angle of an camera is 25 degrees. In most systems the horizontal angle is somewhere between 15 and 20 degrees.
  • Plate position: Ideally, mount the camera in such way that an image of the license plate is captured where the license plate is in the center of in the recorded image.
  • Occlusion: Avoid possible blocking objects in the view path of the camera such as (moveable) bars.
  • Contrast: For contrast we use the difference in 8bit gray levels between the characters at the license plate and the license plate background. This difference should be at least 15.
  • Resolution: For resolution we use the term pixels per stroke to define a minimum requirement for reliable ALPR. The image on the right shows what is meant with stroke. Because the stroke width is country and plate style dependent we do not use pixels/cm. In general the resolution for best ALPR performance should be at least 2.7 pixels/stroke.

In addition, blurring introduced through high compression or motion should be prevented at all times. Any image quality requirements not met may impact the performance of the ALPR engine.

When you run into issues deploying, integration and using the Intrada products, please refer to the corresponding “Troubleshooting” sections in the corresponding Documentation. In case this doesn’t solve your issue, you can refer to the Intrada support page and issue a ticket for our support team. After you have submitted your ticket, you will be contacted shortly to find a way towards a possible solution.

Before going to the support page, please ensure you have the following available:

  • Log-in credentials to the deliveries site.
  • Configuration that was used (module versions, settings, etc).
  • Sample images to reproduce the issue you experienced.

Direct link to the support page:

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