Image inspection of printed matter with a master image

Patent metadata

Field	Value
Publication number	US-9310737-B2
Application number	US-201414468263-A
Country	US
Kind code	B2
Filing date	Aug 25, 2014
Priority date	Aug 27, 2013
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

An image inspection apparatus includes a first-image obtaining unit, a scanned-image obtaining unit, a second-image obtaining unit, first and second registration units, a combining unit, and an inspection unit. The first-image obtaining unit obtains a first image generated by scanning a sheet on which a predetermined image has been printed. The scanned-image obtaining unit obtains a scanned image generated by scanning a printed matter produced by printing a second image additionally on the sheet. The second-image obtaining unit obtains the second image. The first registration unit performs registration between the first and scanned images. The second registration unit performs registration between the second image and the scanned image. The combining unit generates a master image by combining the first and second images based on registration results performed by the first and second registration units. The inspection unit inspects the printed matter by comparing the scanned image against the master image.

First claim

What is claimed is:

1. An image inspection apparatus comprising:
a first-image obtaining unit configured to obtain a first image generated by scanning a sheet on which a predetermined image has been printed in advance;
a scanned-image obtaining unit configured to obtain a scanned image generated by scanning a printed matter produced by printing a second image additionally on the sheet;
a second-image obtaining unit configured to obtain the second image;
a first registration unit configured to determine a first registration shift amount of the first image based on a difference in pixel values in a first reference area of the first image and the scanned image;
a second registration unit configured to determine a second registration shift amount of the second image based on a difference in pixel values of a second reference area of the second image and the scanned image;
a combining unit configured to generate a master image by relatively moving the first image and the second image based on the first registration shift amount and the second registration shift amount and combining the relatively moved version of the first image and the second image into the master image; and
an inspection unit configured to inspect the printed matter by comparing the scanned image against the master image.

2. The image inspection apparatus according to claim 1 , wherein
the first registration unit extracts multiple first reference points from the first image and extracts, as the first reference area, an image in a predetermined area containing any one of the multiple first reference points,
the second registration unit extracts multiple second reference points from the second image and extracts, as the second reference area, an image in a predetermined area containing any one of the multiple second reference points, and
the inspection unit inspects the printed matter by comparing between the scanned image against and the master image on a per-pixel basis with reference to any one of a set of the multiple first reference points and a set of the multiple second reference points.

3. The image inspection apparatus according to claim 1 , wherein
the first registration unit performs the registration between the first image and the scanned image by extracting, from the first image, multiple first reference images, each of the multiple first reference images being in a different one of multiple predetermined areas and containing a first reference point, and performing, on each of the first reference images, registration between the first reference image and an image contained in the scanned image and matching with the first reference area,
the second registration unit performs the registration between the second image and the scanned image by extracting, from the second image, multiple second reference images, each of the multiple second reference images being in a different one of multiple predetermined areas and containing a second reference point, and performing, on each of the second reference images, registration between the second reference image and an image contained in the scanned image and matching with the second reference area, and
the combining unit performs the registration between the first image and the second image after applying geometry correction to the first image based on a result of the registration performed by the first registration unit and applying geometry correction to the second image based on a result of the registration performed by the second registration unit.

4. The image inspection apparatus according to claim 1 , wherein the combining unit generates the master image by combining pixels, each of the pixels being one of multiple pixels making up the second image and belonging to pixels to which developer is to be applied, with the first image.

5. The image inspection apparatus according to claim 1 , further comprising a correction unit configured to correct pixel values of pixels, each of the pixels being one of multiple pixels making up the first image and belonging to a no-image portion at which developer is not to be applied, to a first predetermined value.

6. The image inspection apparatus according to claim 1 , further comprising a correction unit configured to correct pixel values of pixels, each of the pixels being one of multiple pixels making up the first image and belonging to an out-of-predetermined-image portion, the out-of-predetermined-image portion not making up the predetermined image, to a second predetermined value.

7. An image forming system comprising:
an image forming unit configured to produce a printed matter by forming a second image additionally on a sheet on which a predetermined image has been printed in advance;
an image scanning unit configured to generate a first image by scanning the sheet and generate a scanned image by scanning the printed matter;
an image obtaining unit configured to obtain the second image;
a first registration unit configured to determine a first registration shift amount of the first image based on a difference in pixel values in a first reference area of the first image and the scanned image;
a second registration unit configured to determine a second registration shift amount of the second image based on a difference in pixel values of a second reference area of the second image and the scanned image;
a combining unit configured to generate a master image by relatively moving the first image and the second image based on the first registration shift amount and the second registration shift amount and combining the relative moved version of first image and the second image into the master image; and
an inspection unit configured to inspect the printed matter by comparing the scanned image against the master image.

8. An image inspection method comprising:
obtaining a first image generated by scanning a sheet on which a predetermined image has been printed in advance;
obtaining a scanned image generated by scanning a printed matter produced by printing a second image additionally on the sheet;
obtaining the second image;
determining a first registration shift amount of the first image based on a difference in pixel values in a first reference area of the first image and the scanned image;
determining a second registration shift amount of the second image based on a difference in pixel values of a second reference area of the second image and the scanned image;
generating a master image by relatively moving the first image and the second image based on the first registration shift amount and the second registration shift amount and combining the relatively moved version of first image and the second image into the master image; and
inspecting the printed matter by comparing the scanned image against the master image.

Assignees

• Kojima Keiji
• Ricoh Co Ltd

Inventors

• Kojima Keiji

Classifications

• G03G15/36 Primary

  Editing, i.e. producing a composite image by copying one or more original images or parts thereof · CPC title