System And Method For Print Production Sheet Identification

• US 20110080607A1
• Filed: 10/01/2009
• Published: 04/07/2011
• Est. Priority Date: 10/01/2009
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Ulichney, Robert, Gaubatz, Matthew, Rouse, David
• Granted Patent: US 8,760,670 B2
• Time in Patent Office: Days
• US Class Current: 358/1.15
• CPC Class Codes: G06V 30/418 Document matching, e.g. of document images
• CPC Class Codes: H04N 1/00045 using a reference pattern designed for the purpose, e.g. a test chart

Abstract

A system and method is disclosed for print production sheet identification. The method discloses: receiving a set of calibration sheets; collecting an array of pixel samples from at least one of the calibration sheets according to a set of pixel sampling rules to generate at least one reference sample array; capturing an image of a set of physical sheets generated from the set of calibration sheets; collecting an array of pixel samples from at least one of the imaged physical sheets according to the set of pixel sampling rules to generate at least one post-processing sample array; and comparing the post-processing sample array to the reference sample array to determine if the two arrays have less than or equal to a predetermined number of differences. The system discloses: a sampling module, operated by a processor, a scanner, and a comparison module, operated by a processor.

Claims

1. A method, executed by a computer, for print production sheet identification, comprising:

receiving a set of calibration sheets;

collecting an array of pixel samples from at least one of the calibration sheets according to a set of pixel sampling rules to generate at least one reference sample array;

capturing an image of a set of physical sheets generated from the set of calibration sheets;

collecting an array of pixel samples from at least one of the imaged physical sheets according to the set of pixel sampling rules to generate at least one post-processing sample array; and

comparing the post-processing sample array to the reference sample array to determine if the two arrays have less than or equal to a predetermined number of differences.

2. The method of claim 1, wherein the pixel sampling rules include:

a sampling region, which specifies an area on each sheet which is to be sampled;

a sampling rate, which specifies a granularity of collecting pixels within the sampling region; and

a pixel bit-depth.

3. The method of claim 2, further comprising:

reducing the “

pixel bit-depth”

of the calibration sheets and the imaged physical sheets to a reduced pixel bit-depth, according to a set of threshold criteria and techniques.

4. The method of claim 3, wherein threshold criteria and techniques include:

a MSNZB (Most Significant Non Zero Bit) threshold technique which identifies a MSNZB within a subset of bits within the array of pixel samples and replaces said subset of bits with one state if the subset of bits are greater than or equal to the MSNZB, and replaces said subset of bits with another state if the subset of bits are less than the MSNZB.

5. The method of claim 3, wherein threshold criteria and techniques include:

a Midpoint threshold technique which identifies a bit value halfway between a maximum and minimum bit value within a subset of bits within the array of pixel samples and replaces said subset of bits with one state if the subset of bits are greater than or equal to the halfway value, and replaces said subset of bits with another state if the subset of bits are less than the halfway value.

6. The method of claim 3, wherein threshold criteria and techniques include:

a Mean threshold technique which calculates an average bit value within a subset of bits within the array of pixel samples and replaces said subset of bits with one state if the subset of bits are greater than or equal to the average value, and replaces said subset of bits with another state if the subset of bits are less than the average value.

7. The method of claim 3:

wherein the “

pixel bit-depth”

is reduced to 1-bit.

8. The method of claim 1:

wherein the set of physical sheets are generated by a set of sheet processing devices operating on the set of calibration sheets.

9. The method of claim 1, wherein comparing includes:

comparing the post-processing sample array to each of several reference sample arrays, each corresponding to a different one of the calibration sheets, until the arrays have a smallest number of differences.

10. The method of claim 1, wherein comparing includes:

comparing the post-processing sample array to the reference sample array using one technique from a group including;

a sum-squared-errors technique, an XOR-based sum-squared-errors technique, and a measurement of correlation technique.

11. The method of claim 10:

wherein the pixel sampling rules include a pixel bit-depth equivalent to 1-bit; and

wherein comparing using the XOR-based sum-squared-errors technique includes;

comparing corresponding bits between each of the arrays using an XOR operation;

counting the XOR'"'"'d bits using a population count operation; and

identifying the reference sample array as similar to the post-processing sample array if the population count total is less than or equal to the predetermined number of differences.

12. The method of claim 11, further comprising

sizing the arrays to individually fit into a computational register within a computational device;

and

executing the XOR operation using the computational register.

13. The method of claim 1, wherein comparing includes:

outputting one from a group including;

a match signal if the arrays have less than or equal to the predetermined number of differences, a not match signal if the arrays have more than the predetermined number of differences, and a distance value equaling the predetermined number of differences.

14. The method of claim 1:

wherein comparing includes, comparing a first post-processing sample array, within a set of contiguous post-processing sample arrays, to each of several reference sample arrays, until a first reference sample array is identified as have less than or equal to the predetermined number of differences than the first post-processing sample array; and

further comprising identifying a set of contiguous reference sample arrays, beginning with the first reference sample array and having a same set size as the set of contiguous post-processing sample arrays, as corresponding the set of contiguous post-processing sample arrays.

15. An article comprising at least one computer-readable storage medium containing computer instructions for print production sheet identification, further comprising:

receiving a set of calibration sheets;

collecting an array of pixel samples from at least one of the calibration sheets according to a set of pixel sampling rules to generate at least one reference sample array;

capturing an image of a set of physical sheets generated from the set of calibration sheets;

collecting an array of pixel samples from at least one of the imaged physical sheets according to the set of pixel sampling rules to generate at least one post-processing sample array; and

comparing the post-processing sample array to the reference sample array to determine if the two arrays have less than or equal to a predetermined number of differences.

16. A system for print production sheet identification, comprising:

a sampling module, operated by a processor, for;

receiving a set of calibration sheets; and

collecting an array of pixel samples from at least one of the calibration sheets according to a set of pixel sampling rules to generate at least one reference sample array;

a scanner for capturing an image of a set of physical sheets generated from the set of calibration sheets;

the sampling module also;

collecting an array of pixel samples from at least one of the imaged physical sheets according to the set of pixel sampling rules to generate at least one post-processing sample array; and

a comparison module, operated by a processor, for comparing the post-processing sample array to the reference sample array to determine if the two arrays have less than or equal to a predetermined number of differences.

17. The system of claim 16:

wherein a format of the calibration sheets is one from a group including;

an electronic document format, logical format, a physical tangible format, and a RIP file format.

18. The system of claim 16:

wherein the physical sheets includes one from a group including;

paper, cardstock, vellum, plastic;

wherein the physical sheets include one from a group including;

text, photos, tables, pictures; and

wherein the physical sheets are collected into one from a group including;

a set of physical sheets, a handout, a book, a pamphlet, a poster.

19. The system of claim 16, further comprising:

a set of sheet processing devices which generate the set of physical sheets by operating on the set of calibration sheets; and

wherein the sheet processing devices include one from a group of devices for;

rendering, printing, routing, tracking, cutting, finishing, coating, sorting, collating, insertion, trimming, and binding, in accordance with a set of print production instructions in an “

electronic job jacket”

.

20. The method of claim 19, further comprising:

a sheet management module for translating signals from the comparison module into feedback for managing the sheet processing devices such that subsequent processing of the physical sheets is in accordance with the set of print production instructions in an “

electronic job jacket”

.