Abstract: A method and apparatus for reading optical symbols is disclosed, which employs defined erasure zones for grading symbols, and for permitting soft decisions to be made with respect to further processing of the symbols. The erasure zones are defined between nominal values within the range of nominal values for the measurable characteristics of the symbol elements which comprise the symbol. The measured actual values of the measurable characteristic are compared to the erasure zones. The number of symbol elements having measured actual values within any one of the erasure zones is used to determine the appropriate steps for further processing of the optical symbol. Measurable characteristics can include dimensions such as width, length, area, volume, as well as other optical characteristics such as color or hue, and shade or depth.

Abstract: A method and apparatus employs a weighted order stored in a weight table for automatically discriminating optical symbols which may be encoded in any one of at least two symbologies. The weighted order may be dynamically updated to reflect the distribution of symbologies as the symbols are acquired and decoded.

Abstract: A method and apparatus employs a weighted order stored in a weight table for automatically discriminating optical symbols which may be encoded in any one of at least two symbologies. The weighted order may be dynamically updated to reflect the distribution of symbologies as the symbols are acquired and decoded.