Method and apparatus for generating optically readable dot image data and recording medium

• US 6,561,423 B2
• Filed: 02/09/2001
• Issued: 05/13/2003
• Est. Priority Date: 04/10/2000
• Status: Expired due to Fees

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Yoshioka, Kenji
• Primary Examiner(s): St. Cyr, Daniel
• Application Number:
  US09/780,451
• Publication Number:
  US 20010028000A1
• Time in Patent Office: 823 Days
• Field of Search: 235/454, 235/455, 235/456, 235/462.01, 235/462.03, 235/462.07, 235/462.11, 235/462.14, 235/462.15, 235/462.25
• US Class Current: 235/454
• CPC Class Codes: G06K 1/121 by printing code marks applying code marks to labels B65C9/46; marking or coding completed packages B65B61/26
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/1417 2D bar codes

Abstract

The present invention selects an appropriate composition pattern even if there is provided a plurality of composition patterns for dot image data based on the number of pixels associated with printing. Namely, in order to print a readable dot, an image data generation method is used for setting a composition pattern of this dot. This method determines the number of pixels associated with printout of the composition pattern in consideration of enlargement of the dot when printed. This method also uses a composition pattern which minimizes dispersion of pixels constituting the corresponding dot. By doing so, the method uniquely determines an optimal dot composition pattern for printing.

Claims

1. A method for generating optically readable dot image data when binary data corresponds to presence or absence of an optically readable dot and said dot is printed in a virtual cell virtually formed on a printout medium, said method comprising:

a first step of determining a count of pixels constituting said virtual cell as a minimum print unit in a typesetting device used for printing said dot on the printout medium;

a second step of determining a count of pixels in said virtual cell associated with printout of said dot in consideration of enlargement of said dot when printed on the printout medium based on said dot image data; and

a third step of, when a plurality of composition patterns are available for the dot image data consisting of the count of pixels determined at the second step, selecting from the plurality of composition patterns a composition pattern which minimizes a dispersion value of pixels constituting said dot image data,

wherein said dispersion value is calculated for each of the composition patterns.

2. The method according to claim 1, wherein

said third step comprises selecting the composition pattern which minimizes said dispersion value by performing area-integration on a square of a distance between a position of each pixel constituting said dot image data and a centroid position based on all pixels constituting said dot image data within all pixels constituting said dot image data.

3. The method according to claim 2, wherein

when said typesetting device generates an image set copy by laser scanning exposure and there is provided a plurality of composition patterns selected by said third step,

said third step further selects a composition pattern which minimizes a count of pixels isolated in a scanning direction of said laser out of the plurality of said composition patterns.

4. The method according to claim 2, wherein

said virtual cell comprises n-by-n square pixels, where n is an integer greater than or equal to 2, in said typesetting device.

5. The method according to claim 2, wherein

a plurality of said virtual cells are adjacently formed in a matrix.

6. The method according to claim 1, wherein

said first step further determines a size of said virtual cell based on minimum and maximum dot distances which a reader optically reading said dot can read.

7. The method according to claim 1, wherein

when said typesetting device generates an image set copy by laser scanning exposure and there is provided a plurality of composition patterns selected by said third step,

said third step further selects a composition pattern which minimizes a count of pixels isolated in a scanning direction of said laser out of the plurality of said composition patterns.

8. The method according to claim 1, wherein

said virtual cell comprises n-by-n square pixels, where n is an integer greater than or equal to 2, in said typesetting device.

9. The method according to claim 1, wherein

a plurality of said virtual cells are adjacently formed in a matrix.

10. An apparatus for generating optically readable dot image data when binary data correspond to presence or absence of an optically readable dot and said dot is printed in a virtual cell virtually formed on a printout medium, said apparatus comprising:

first means for determining a count of pixels constituting said virtual cell as a minimum print unit in a typesetting device used for printing said dot on the printout medium;

second means for determining a count of pixels in said virtual cell associated with printout of said dot in consideration of enlargement of said dot when printed on the printout medium based on said dot image data; and

third means for, when a plurality of composition patterns are available for the dot image data consisting of the count of pixels determined by the second means, selecting a composition pattern which minimizes a dispersion value of pixels constituting said dot image data,

wherein said dispersion value is calculated for each of the composition patterns.

11. A computer-readable recording medium having stored thereon program code for, in order to generate optically readable dot image data when binary data corresponds to presence or absence of an optically readable dot and said dot is printed in a virtual cell formed on a printout medium, instructing a computer to perform:

a first process for determining a count of pixels constituting said virtual cell as a minimum print unit in a typesetting device used for printing said dot on the printout medium;

a second process for determining a count of pixels in said virtual cell associated with printout of said dot in consideration of enlargement of said dot when printed on the printout medium based on said dot image data; and

a third process for selecting a composition pattern which, when a plurality of composition patterns are available for the dot image data consisting of the count of pixels determined in the second process, minimizes a dispersion value of pixels constituting said dot image,

wherein said dispersion value is calculated for each of the composition patterns.