Systems and methods for decoding two-dimensional matrix symbols with incomplete or absent fixed patterns
AssigneeCognex Corporation
InventorsXiangyun YE, Xianju WANG, James A. NEGRO
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Abstract
Systems and methods for reading a two-dimensional matrix symbol or for determining if a two-dimensional matrix symbol is decodable are disclosed. The systems and methods can include a data reading algorithm that receives an image, locates at least a portion of the data modules within the image without using a fixed pattern, fits a model of the module positions from the image, extrapolates the model resulting in predicted module positions, determines module values from the image at the predicted module positions, and extracts a binary matrix from the module values.
Claims20
A system for reading a two-dimensional matrix symbol including data modules each having a module value and a module position, the two-dimensional matrix symbol encoding a data set, the system comprising:
- an imaging device, the imaging device configured to acquire an image containing at least a portion of the two-dimensional matrix symbol;
- a processor, the processor operatively coupled to the imaging device, the processor configured to execute a data reading algorithm, wherein the data reading algorithm receives the image, locates at least a portion of the data modules within the image without using a fixed pattern, fits a model of the module positions from the image, extrapolates the model resulting in predicted module positions, determines module values from the image at the predicted module positions, and extracts a binary matrix from the module values;
- and
- a binary matrix decoder operatively coupled to the processor, the binary matrix decoder configured to execute a decoding algorithm that decodes the binary matrix.
A method of reading a two-dimensional matrix symbol including data modules each having a module value and a module position, the two-dimensional matrix symbol encoding a data set, the method comprising:
- receiving an image at a processor, the image containing at least a portion of the two-dimensional matrix symbol;
- locating, using the processor, at least a portion of the data modules within the image without using a fixed pattern;
- fitting, using the processor, a model to at least a portion of the module positions from the image;
- extrapolating, using the processor, the model to define predicted module positions;
- determining, using the processor, the module values from the image at the predicted module positions;
- extracting, using the processor, a binary matrix from the module values;
- and
- decoding the binary matrix.
A system for determining if a two-dimensional matrix symbol is decodable, the two-dimensional matrix symbol including data modules each having a module value and a module position, the system comprising:
- an imaging device, the imaging device configured to acquire an image containing the two-dimensional matrix symbol;
- a processor, the processor operatively coupled to the imaging device, the processor configured to execute a data reading algorithm, wherein the data reading algorithm receives the image, locates at least a portion of the data modules within the image without using a fixed pattern, fits a model of the module positions from the image, extrapolates the model resulting in predicted module positions, determines module values from the image at the predicted module positions, and extracts a binary matrix from the module values,
- wherein the data reading algorithm includes a frequency-domain analysis.
Dependencies are inferred from the claim text.