Minimum discrimination information bar code decoding

The ubiquitous super market checkout scanner is indeed a well engineered and effective device. There is, nevertheless, demand for yet better devices. Existing scanners rely on simple and indeed low cost signal processing to interpret bar code signals. These methods, nevertheless, fundamentally limit label reading and can not be extended. A new method based on the deterministic expectation-maximization (DEM) algorithm is described here. First result show a substantial improvement in label reading depth-of-field, an important performance parameter for bar code readers