Analog waveform decoder utilizing histogram of edge sizes
US5311001A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 23, 1993 |
| Grant date | May 10, 1994 |
| Priority date | — |
| Expiry date | Jul 23, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/14
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for decoding information contained in an analog waveform representative of a bar code symbol comprising the steps of identifying a decodable portion of an analog waveform; processing said decodable portion to obtain a plurality of waveform descriptors; and performing a high and low density decoding process to one or more of said plurality of waveform descriptors for decoding information contained in either a high or low density symbol respectively, is disclosed. The high density decoder used for decoding high density symbols utilizes extrema extents, i.e., areas of the peaks and valleys of the analog waveform which directly correlate to the size of the bars/spaces of a high density bar code. After locating the seed point of the waveform, each extrema extent is generated and thresholded at each peak/valley location to decide its size. The high density decoder is adaptive in that the thresholding extent value is updated as the solution grows away from the seed point. The low density decoder used for decoding low density symbols utilizes the widths of the peaks/valleys for decoding purposes and utilizes a histogramming and backtracking technique for removing noise levels from…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.