You can read barcodes or matrix codes using pdfToolbox Switchboard Action 'Read Barcode' under the Group 'Report' in Switchboard. You can either define the position and size of the custom rectangle where you want to find the Barcode or work it automatically via "Mouse selection".
This will render the selected region to a grayscale buffer at a high resolution.

The results (value, type of barcode, bar width reduction, exact position and dimension of the barcode etc.), if any barcode or matrix code is found, will be shown in a new window from where the barcode information can be selected and copied, like the one below:

You can determine barcode properties like coordinates, height, module width, symbology (type), bar width reduction or width of barcode, using Checks in pdfToolbox (screenshot below).

The identified barcodes and their parameters are displayed in the result view. However only the trigger for the selected Check property is available in the Trigger values. That is unfortunate if you want to e.g. use the barcode value in JavaScript.

That can be resolved by adding additional properties to the Check, e.g. "Barcode value", "Symbology (type of barcode/matrix code) and "Barwidth reduction (%)". You may add any of the barcode/matrix code related Check properties. You have to make sure that the Condition is set up to always generate a hit as in this example.

In this example we have added all Check properties.

You may download the Check from here.

Compatible with pdfToolbox 15 or newer:

Compatible with pdfToolbox 12 or newer (without color distance, quiet zone and rotation Check properties):

If you want more information about barcodes and matrix codes in general, please download the "Barcode Reference Manual":