Image inspection method, image inspection device, program, and image recording system

• US 10,311,561 B2
• Filed: 09/28/2017
• Issued: 06/04/2019
• Est. Priority Date: 09/30/2016
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Ukishima, Masayuki
• Primary Examiner(s): Woldemariam, Aklilu K
• Application Number:
  US15/717,947
• Publication Number:
  US 20180096472A1
• Time in Patent Office: 614 Days
• Field of Search: 382254, 382145, 382149, 382270, 382309, 382312, 347 14, 347 16, 347 19
• CPC Class Codes: B41J 2/155 for line printing
• CPC Class Codes: B41J 2/2139 Compensation for malfunctioning nozzles creating dot place or dot size errors generating single droplets or particles on demand by pressure, e.g. electromechanical transducers B41J2/045
• CPC Class Codes: B41J 2/2142 Detection of malfunctioning nozzles generating single droplets or particles on demand by pressure, e.g. electromechanical transducers B41J2/045, B41J2/05; jet deflection sensors B41J2/125; for cleaning purposes B41J2/16579
• CPC Class Codes: B41J 2/2146 for line print heads
• CPC Class Codes: B41J 2029/3935 by means of printed test patterns
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/30108 Industrial image inspection
• CPC Class Codes: G06T 2207/30168 Image quality inspection
• CPC Class Codes: G06T 7/0002 Inspection of images, e.g. flaw detection
• CPC Class Codes: G06T 7/97 Determining parameters from multiple pictures depth or shape recovery from multiple images G06T7/55; stereo camera calibration G06T7/85
• CPC Class Codes: G06V 10/751 Comparing pixel values or logical combinations thereof, or feature values having positional relevance, e.g. template matching
• CPC Class Codes: G06V 10/993 Evaluation of the quality of the acquired pattern
• CPC Class Codes: G06V 2201/06 Recognition of objects for industrial automation
• CPC Class Codes: H04N 1/00002 Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for error detection, error correction or monitoring in digital computers or digital computer components G06F11/00
• CPC Class Codes: H04N 1/6041 for controlling uniformity of color across image area

Abstract

The image inspection method includes: a step of acquiring data of an inspection image obtained by capturing an image of a recorded matter recorded by an image recording system that performs a compensation process of compensating for a defect caused by a failure in an image formation element, using an imaging apparatus; a step of acquiring data of a reference image; and a step of comparing the data of the inspection image with the data of the reference image to determine whether there is a defect at each position of the inspection image. The defect detection step includes a process that makes a defect detection performance different in a compensation application region and a compensation non-application region other than the compensation application region, on the basis of compensation position information of the failure in the image formation element to which the compensation process has been applied.

Claims

1. An image inspection method comprising:

an inspection image acquisition step of acquiring data of an inspection image obtained by capturing an image of a recorded matter recorded by an image recording system that comprises a plurality of image formation elements and performs a compensation process of compensating for a defect caused by a failure in the image formation element, using an imaging apparatus;

a reference image acquisition step of acquiring data of a reference image which is a reference for detecting a defect in the recorded matter; and

a defect detection step of comparing the data of the inspection image with the data of the reference image to determine whether there is a defect at each position of the inspection image,

wherein the defect detection step includes a process that makes a defect detection performance different in a compensation application region and a compensation non-application region other than the compensation application region, on the basis of compensation position information of the failure in the image formation element to which the compensation process has been applied,

wherein in the defect detection step, a plurality of defect detection methods with different detection performances are defined, and

the defect detection step includes a selection step of selecting a defect detection method to be applied to determine whether there is a defect at each position from the plurality of defect detection methods on the basis of the compensation position information,

wherein in a case in which a set of the compensation positions of the failure in the image formation element in the inspection image is a set T, a set of the compensation positions of the failure in the image formation element in the reference image is a set R, a set of positions that are included in the set T and the set R is a first position set, a set of positions that are included in the set T and are not included in the set R is a second position set, a set of positions that are not included in the set T and are included in the set R is a third position set, and a set of positions that are not included in the set T and the set R is a fourth position set, in the selection step, different defect detection methods are selected for at least the second position set and the fourth position set.

2. The image inspection method according to claim 1,

wherein the detection performance is defect detection accuracy determined by a combination of a correct detection performance that accurately determines a defect in the recorded matter and an erroneous detection avoidance performance that avoids erroneously determining a non-defect position of the recorded matter to be a defect, and

the defect detection step includes a process that sets the erroneous detection avoidance performance in the compensation application region to be higher than the erroneous detection avoidance performance in the compensation non-application region.

3. The image inspection method according to claim 1,

wherein the defect detection method includes

a region determination step of determining an arithmetic region for extracting a signal which is suspected as a defect,

a signal intensity determination step of determining intensity of the signal suspected as a defect from the arithmetic region determined in the region determination step, and

a defect presence/absence determination step of determining whether there is a defect, on the basis of the intensity of the signal determined in the signal intensity determination step, using a threshold value, and

the plurality of defect detection methods include defect detection methods in which at least arithmetic methods or parameters used in an arithmetic operation are different in at least one of the region determination step, the signal intensity determination step, or the defect presence/absence determination step.

4. The image inspection method according to claim 3,

wherein the plurality of defect detection methods include defect detection methods in which the arithmetic regions determined in the region determination step have different sizes.

5. The image inspection method according to claim 3,

wherein the plurality of defect detection methods include defect detection methods in which arithmetic methods used for the arithmetic operation in the signal intensity determination step or the parameters used for the arithmetic operation in the signal intensity determination step are different from each other.

6. The image inspection method according to claim 3,

wherein the plurality of defect detection methods include defect detection methods in which the threshold values used in the defect presence/absence determination step are different from each other.

7. The image inspection method according to claim 3,

wherein the defect presence/absence determination step includes a statistical determination process that finally statistically determines whether there is a defect on the basis of a determination data group for a defect and a non-defect determined at a plurality of positions, and

determination criteria of the statistical determination process are set to be different in the compensation application region and the compensation non-application region, on the basis of the compensation position information.

8. The image inspection method according to claim 1,

wherein, among the plurality of defect detection methods, the defect detection method used for the second position set has a higher erroneous detection avoidance performance than the defect detection method used for the fourth position set.

9. The image inspection method according to claim 1,

wherein the image recording system is a line-head-type ink jet printing system and the image formation element is a nozzle of a line head.

10. The image inspection method according to claim 9,

wherein the compensation process of compensating for the failure in the image formation element is a non-jetting correction process.

11. The image inspection method according to claim 1,

wherein the defect is a streak defect.

12. The image inspection method according to claim 1,

wherein the reference image is generated by capturing an image of a reference image generating recorded matter, which has been recorded in advance by the image recording system or other image recording systems, using the imaging apparatus or other imaging apparatuses.

13. The image inspection method according to claim 1,

wherein the reference image is generated on the basis of image data that is used to record the recorded matter using the image recording system.

14. An image inspection device comprising:

a first interface that acquires data of an inspection image obtained by capturing an image of a recorded matter recorded by an image recording system that comprises a plurality of image formation elements and performs a compensation process of compensating for a defect caused by a failure in the image formation element, using an imaging apparatus, wherein the first interface is formed by at least one of a data input terminal, a communication interface, or a media interface, or a plurality of combinations thereof;

a second interface that acquires data of a reference image which is a reference for detecting a defect in the recorded matter, wherein the second interface is formed by at least one of a data input terminal, a communication interface, or a media interface, or a plurality of combinations thereof; and

a detection circuit that compares the data of the inspection image with the data of the reference image to determine whether there is a defect at each position of the inspection image,

wherein the detection circuit performs a process that makes defect detection performances different in a compensation application region and a compensation non-application region other than the compensation application region, on the basis of compensation position information of the failure in the image formation element to which the compensation process has been applied,

wherein a plurality of defect detection methods with different detection performances are defined, and

the detection circuit selects a defect detection method to be applied to determine whether there is a defect at each position from the plurality of defect detection methods on the basis of the compensation position information,

wherein in a case in which a set of the compensation positions of the failure in the image formation element in the inspection image is a set T, a set of the compensation positions of the failure in the image formation element in the reference image is a set R, a set of positions that are included in the set T and the set R is a first position set, a set of positions that are included in the set T and are not included in the set R is a second position set, a set of positions that are not included in the set T and are included in the set R is a third position set, and a set of positions that are not included in the set T and the set R is a fourth position set, in the selection step, different defect detection methods are selected for at least the second position set and the fourth position set.

15. An image recording system comprising:

a plurality of image formation elements;

a processing circuit that performs a compensation process of compensating for a defect caused by a failure in the image formation element and reducing visibility of the defect;

an imaging apparatus that captures an image of a recorded matter recorded by the image formation elements;

a first interface that acquires data of an inspection image obtained by capturing the image of the recorded matter using the imaging apparatus, wherein the first interface is formed by at least one of a data input terminal, a communication interface, or a media interface, or a plurality of combinations thereof;

a second interface that acquires data of a reference image which is a reference for detecting a defect in the recorded matter, wherein the second interface is formed by at least one of a data input terminal, a communication interface, or a media interface, or a plurality of combinations thereof; and

a detection circuit that compares the data of the inspection image with the data of the reference image to determine whether there is a defect at each position of the inspection image,

wherein the detection circuit performs a process that makes a defect detection performance different in a compensation application region and a compensation non-application region other than the compensation application region, on the basis of compensation position information of the failure in the image formation element to which the compensation process has been applied,

wherein a plurality of defect detection methods with different detection performances are defined, and

the detection circuit selects a defect detection method to be applied to determine whether there is a defect at each position from the plurality of defect detection methods on the basis of the compensation position information,

wherein in a case in which a set of the compensation positions of the failure in the image formation element in the inspection image is a set T, a set of the compensation positions of the failure in the image formation element in the reference image is a set R, a set of positions that are included in the set T and the set R is a first position set, a set of positions that are included in the set T and are not included in the set R is a second position set, a set of positions that are not included in the set T and are included in the set R is a third position set, and a set of positions that are not included in the set T and the set R is a fourth position set, in the selection step, different defect detection methods are selected for at least the second position set and the fourth position set.

16. A non-transitory computer-readable tangible recording medium including a program that causes a computer to perform:

an inspection image acquisition step of acquiring data of an inspection image obtained by capturing an image of a recorded matter recorded by an image recording system that comprises a plurality of image formation elements and performs a compensation process of compensating for a defect caused by a failure in the image formation element, using an imaging apparatus;

a reference image acquisition step of acquiring data of a reference image which is a reference for detecting a defect in the recorded matter; and

a defect detection step of comparing the data of the inspection image with the data of the reference image to determine whether there is a defect at each position of the inspection image,

wherein the defect detection step includes a process that makes a defect detection performance different in a compensation application region and a compensation non-application region other than the compensation application region, on the basis of compensation position information of the failure in the image formation element to which the compensation process has been applied,

wherein in the defect detection step, a plurality of defect detection methods with different detection performances are defined, and

the defect detection step includes a selection step of selecting a defect detection method to be applied to determine whether there is a defect at each position from the plurality of defect detection methods on the basis of the compensation position information,

wherein in a case in which a set of the compensation positions of the failure in the image formation element in the inspection image is a set T, a set of the compensation positions of the failure in the image formation element in the reference image is a set R, a set of positions that are included in the set T and the set R is a first position set, a set of positions that are included in the set T and are not included in the set R is a second position set, a set of positions that are not included in the set T and are included in the set R is a third position set, and a set of positions that are not included in the set T and the set R is a fourth position set, in the selection step, different defect detection methods are selected for at least the second position set and the fourth position set.