Restoration of out of Focus Barcode Images Using Wiener Filter

Barcode capturing using embedded camera in mobile phone is prone to producing images with out of focus blurring. Barcode decoding systems usually fail to decode barcodes from an image that is affected by image blurring. With macro function, users are able to capture sharp barcodes. Unfortunately, low end and mid range cameras usually do not have macro function which enables close range image capturing. To improve barcode recognition, we propose a technique to restore barcode images before the decoding process. First, we identify and calculate the point spread function (PSF) parameter and radius of the blur in Cepstrum domain. Then we restore the degraded image using Wiener filter. Experiments on both synthetic and real images show that our technique is adept in estimating the radius of the blur. The Wiener filter gives satisfactory result when it is used to restore blurred images with the acquired PSF from the preceding step.