I was recently asked about how to decode QR barcodes. To demonstrate how to do this, I wrote a simple plugin for ImageJ which does exactly that.

Binary downloads and source code are available on the project page.

Most of the heavy lifting in the plugin is performed by the ZXing library for Java (also commonly known as the Barcode Scanner app for Android). I added a wrapper around this to make it play well with ImageJ, and specifically ImageJ’s macros, so you can decode batches of images with ease.