Since Linux image includes Python and OpenCV library it is recommendable to use them first, if you are not familiar with OpenCV, please check the information provided in this link as a good start point.
Also, you can check more specific information about barcode detection using Python and OpenCV in this additional link: http://opencvpython.blogspot.com/2012/05/barcode-detection.html where you can find the programming code.
Thank you Carlos. I will certainly look into the links you provided. I guess a a quick already written library was too much to hope for. At least I will get to learn a bit of image-processing!