Patent attributes
Systems and methods for successfully decoding optical images of objects of interest when such objects are situated outside a conventional working range of an imaging system, or when such objects are degraded. The systems and methods are based upon a comparison of computed signals corresponding to distorted images that would be obtained from known objects, such as barcodes, when viewed outside a working range, or when degraded, with actual signals obtained from the object of interest. The computed signals in one embodiment are recorded in a lookup table. An advantage of the systems and methods disclosed is that there results a smooth, monotonic probability of correctly decoding the image of interest, even beyond the working distance. A handheld or portable apparatus useful for practicing the invention is also disclosed.