A bar code location algorithm using a two-dimensional approach

Proposes a method for locating bar code blocks on parcels. One of the main difficulties involved is the combination of the very poor quality and the potential high complexity of the gray-level images. The image resolution has been chosen to be as low as possible in order to enlarge the field of view for a given number of CCD elements. Furthermore the focus of the camera has previously needed to be kept constant in spite of the variation in height of the objects resulting in the presence of high convolution distortion such that the width of the point spread function can be much larger than the width of a single stripe. The approach relies on the extraction of areas having a high density of mono-oriented gradient. This bar code finder algorithm works correctly for all images of a base provided by the French postal services