IMAGE DATA BINARIZATION METHODS ENABLING OPTICAL READER TO READ FINE PRINT INDICIA

In the present invention, a bar code reader captures an initial image map corresponding to a scene, then subjects the initial image map to an interpolation step wherein values for constructed pixels positionally intermediate pixel values of the initial image map are interpolated as a function of the initial image map pixel values bordering the constructed pixels. After an interpolated image map is constructed, the interpolated image map is subjected to a binarization step wherein grey scale pixel values of the interpolated image map are converted into binary (1 or 0) pixel values by way of a thresholding process. In the thresholding process, grey scale pixel values are compared to a threshold in the grey scale range, then set to 1 if they are above the threshold and set to 0 if below the threshold. The pixel values of the resulting binarized interpolated image map are then analyzed to determine the identity of a message which may be encoded in any symbol which may be represented in the binarized interpolated image map.