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Read the QR Code

Aim:

Devise an algorithm that reads QR codes from images.

Input:

A set of images with QR Codes captured under different lighting conditions.

Images are stored in the read_qr_code directory.

Output:

A position and text read from a QR Code. The read text should be drawn in the input image.

Hints:

This exercise shows the concept of performing one of the most typical vision problems. It can be solved using a predefined set of filters. In this case, only a single filter is used to determine the code position and read data from it.

To get images from a directory, the EnumerateImages filter should be used. To find the QR Code in an image, use a high-level ReadSingleDataCode filter. The DrawStrings_SingleColor filter may be helpful to show the results.

Labeling connections is explained in this article.

Solution (AVS):

  1. Add the EnumerateImages filter to the ACQUIRE section to obtain images from a directory. Enter the image directory path into the inDirectory input.

  2. Add the ReadSingleDataCode filter to the PROCESS section. Connect the outImage output of the EnumerateImages filter to the inImage input of the ReadSingleDataCode filter.

  3. Add the DrawStrings_SingleColor filter to the project and configure the inputs: inLocations and inColor. Set the inSize to 20.

  4. Connect the outDataCode.Text output of the ReadSingleDataCode filter to the inStrings input of the DrawStrings_SingleColor filter.

  5. Add the outImage of the DrawStrings_SingleColor filter to a preview window.

  6. Use Auto-Tune functionality to automatically set the parameters of the ReadSingleDataCode filter. To do this, right-click on the filter and open Auto-Tune window. Select the Auto-Tune button to start the process. The filter will automatically adjust its parameters to achieve optimal performance.

Main macrofilter reads data from a QR code and writes result on an input image.