Locating 2-D bar codes

A system for locating a two-dimensional bar code image, including identifiable start and stop patterns, within a stored image representing a scanned image area which may include said two-dimensional bar code image, comprising:

• sampling means for sampling said stored image along spaced parallel scan lines in a first direction across a potential bar code image location included in said image area to provide first scan line samplings, and for similarly sampling said stored image in at least one additional direction having an angular separation from said first direction to provide additional scan line samplings;
• analysis means, coupled to said sampling means, for analyzing said first and additional scan line samplings to identify bar code start and stop patterns traversed by said samplings;
• correlating means, coupled to said analysis means, for correlating said bar code start and stop patterns as representative of a common bar code image (i) if two start patterns, or two stop patterns, are identified in scan line samplings taken along parallel scan lines having not more than a predetermined lateral spacing and (ii) if a start pattern and a stop pattern are identified in the same scan line sampling with said patterns having not more than a predetermined separation, to provide correlated start and stop pattern data representing said bar code image;
• bounds identifying means, coupled to said correlating means, for utilizing said correlated start and stop pattern data representing said bar code image to derive data identifying a nominally rectangular area bounding said bar code image;
• and
• output port means, coupled to said bounds identifying means, for coupling said data identifying said nominally rectangular area for further use.