Extended depth-of-field optical reader exploiting digital image deconvolution

Non-contact barcode readers usually rely on fixed focus optical systems, which are affected by defocus blurring as the optical code is moved away from the focal position. In this paper we will describe the implementation of image deconvolution algorithms in a DSP-based imaging module. The parameters of the inverse filtering process have been tuned to suit the great part of the operative conditions, while a subset of parameter has been reserved for challenging situations such as bad codes and low light conditions. The performances of the miniature imaging module will be presented along with a discussion of the improvement to be ascribed to the image deconvolution process.