A system for collaborative bar code error detection and correction comprises a network of individual scanning entities for scanning bar-coded labels. Each individual scanning entity includes a scanning system having a decoder for decoding scanned bar code information and a printhead defect identifier for identifying printhead defects from scanned bar code information that cannot be decoded and for constructing printhead defect models for use in correcting future bar code scans. A log is provided at each individual scanning entity for storing locally constructed printhead defect models and printhead defect models that have been constructed at other scanning entities in the network. Each individual scanning entity has an error corrector for correcting erroneous scanned bar code information using the locally stored printhead defect models. Further, each scanning entity includes a network connection for broadcasting locally constructed printhead defect models to the network and for receiving broadcasts of printhead defect models constructed at other scanning entities in the network.

The invention provides methods and appartaus for analysis of images of two-dimensional (2D) bar codes in which a model that has proven successful in decoding of a prior 2D image of a 2D bar code is utilized to speed analysis of images of subsequent 2D bar codes. In its various aspects, the invention can be used in analyzing conventional 2D bar codes, e.g., those complying with Maxicode and DataMatrix standards, as well as stacked linear bar codes, e.g., those utilizing the Codablock symbology. Bar code readers, digital data processing apparatus and other devices according to the invention be used, by way of non-limiting example, to decode bar codes on damaged labels, as well as those screened, etched, peened or otherwise formed on manufactured articles (e.g., from semiconductors to airplane wings). In addition to making bar code reading possible under those conditions, devices utilizing such methods can speed bar code analysis in applications where multiple bar codes of like type are read in succession and/or are read under like circumstances--e.g., on the factory floor, at point-of-sale locations, in parcel deliver and so forth. Such devices can also speed and/or make possible bar code analysis where in applications where multiple bar codes read from a single article--e.g., as in the case of a multiply-encoded airplane propellor or other milled parts. The invention also provides methods and apparatus for optical character recognition and other image-based analysis paralleling the above.

The invention provides methods and appartaus for analysis of images of two-dimensional (2D) bar codes in which a model that has proven successful in decoding of a prior 2D image of a 2D bar code is utilized to speed analysis of images of subsequent 2D bar codes. In its various aspects, the invention can be used in analyzing conventional 2D bar codes, e.g., those complying with Maxicode and DataMatrix standards, as well as stacked linear bar codes, e.g., those utilizing the Codablock symbology. Bar code readers, digital data processing apparatus and other devices according to the invention be used, by way of non-limiting example, to decode bar codes on damaged labels, as well as those screened, etched, peened or otherwise formed on manufactured articles (e.g., from semiconductors to airplane wings). In addition to making bar code reading possible under those conditions, devices utilizing such methods can speed bar code analysis in applications where multiple bar codes of like type are read in succession and/or are read under like circumstances--e.g., on the factory floor, at point-of-sale locations, in parcel deliver and so forth. Such devices can also speed and/or make possible bar code analysis where in applications where multiple bar codes read from a single article--e.g., as in the case of a multiply-encoded airplane propellor or other milled parts. The invention also provides methods and apparatus for optical character recognition and other image-based analysis paralleling the above.