Method for reading out symbol information and device for reading out symbol information

• US 20060175414A1
• Filed: 12/21/2005
• Published: 08/10/2006
• Est. Priority Date: 12/21/2004
• Status: Active Grant

• Current Assignee: Nidec Sankyo Corporation (Nidec Corporation)
• Original Assignee: Nidec Sankyo Corporation (Nidec Corporation)
• Inventors: Nakamura, Hiroshi
• Granted Patent: US 7,380,718 B2
• Time in Patent Office: Days
• US Class Current: 235/462.90
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1456 determining the orientation of the optical code with respect to the reader and correcting therefore
• CPC Class Codes: G06K 7/1486 Setting the threshold-width for bar codes to be decoded

Abstract

To provide a method for reading out symbol information and a device for reading out symbol information which are able to prevent a decline in decoding reliability by reducing noise caused by a quantized error, localized contaminations or the like. The method for reading out symbol information may comprise a process in which the image data, obtained by imaging the symbol information such as bar codes and the like, are converted to corrected image data having zero angle of inclination; a smoothing process in which the corrected image data are smoothed; and a column specifying process in which breakpoints of said symbol information column are specified by computing the total sum in the row direction on the smoothed corrected image data.

Claims

1. A method for reading out symbol information in which symbol information is read by processing the image data obtained by imaging the symbol information recorded on a medium comprising:

an angle changing process in which said image data are converted to corrected image data having zero angle of inclination;

a smoothing process in which said corrected image data are smoothed;

and a column specifying process in which breakpoints of a symbol information column are specified by computing the total sum in the row direction on the corrected image data smoothed by said smoothing process.

2. The method for reading out symbol information as described in claim 1 further comprising a line specifying process in which breakpoints of symbol information lines are specified by setting a group made up with continuous multiple lines on the corrected image data smoothed by said smoothing process, and by computing correlation value rows on the lines for which a group is set as said group is moved relative to said corrected image data.

3. The symbol information readout method as described in claim 1 comprising said symbol information containing a start pattern, which indicates the start of said symbol information, and a stop pattern, which indicates the end of said symbol information;

and said symbol information readout method further comprises a detection process in which said start pattern or said stop pattern is detected by computing the degree of similarity between a prescribed base pattern and run length data rows of bars and spaces for one column in the line direction on said corrected image data.

4. The symbol information readout method as described in claim 2 comprising said symbol information containing a start pattern, which indicates the start of said symbol information, and a stop pattern, which indicates the end of said symbol information;

and said symbol information readout method further comprises a detection process in which said start pattern or said stop pattern is detected by computing the degree of similarity between a prescribed base pattern and run length data rows of bars and spaces for one column in the line direction on said corrected image data.

5. The symbol information readout method as described in claim 1 further comprising a judging process in which whether or not the total number of bars and spaces for one column is equal to the number set in advance in the line direction on said corrected image data is judged.

6. A symbol information readout device comprising a readout means for performing:

an angle changing process in which said image data are converted to corrected image data having zero angle of inclination;

a smoothing process in which said corrected image data are smoothed;

and a column specifying process in which breakpoints of a symbol information column are specified by computing the total sum in the row direction on the corrected image data smoothed by said smoothing process.

7. The symbol information readout device as described in claim 6 comprising said readout means to read out said symbol information being equipped with the tightly adhered stack-type of one dimensional imaging element.

8. A method for reading out symbol information in which symbol information is read by processing the image data obtained by imaging the symbol information recorded on a medium comprising a column specifying process in which breaking points of a column of said symbol information are specified by computing the total sum in the row direction on said image data obtained by imaging;

and a boundary determination process in which, based on a comparison of breaking points of a column specified by said column specifying process with the end of the measured column, the boundary of each row column is determined.

9. A symbol information readout device comprising a means for performing:

a column specifying process in which breaking points of a column of said symbol information are specified by computing the total sum in the row direction on image data obtained by imaging;

and a boundary determination process in which, based on a comparison of breaking points of a column specified by said column specifying process with the end of the measured column, the boundary of each row column is determined.

10. The symbol information readout device as described in claim 9 further comprising being equipped with the tightly adhered stack-type of one dimensional imaging element which images said symbol information.