Image inspection apparatus, image inspection method, and image inspection program
An image inspection apparatus includes an image reader that reads an original image formed on a recording material based on a print job and generates a read image, and a hardware processor that analyzes the read image and performs an image inspection, wherein the hardware processor: acquires the read image from the image reader, detects an edge from the read image, and excludes a region near the edge from a target of the image inspection; performs a predetermined filter process on the read image after the exclusion process to generate a first reference image compares the read image after the exclusion process with the first reference image to generate a first comparison image; and binarizes the first comparison image using a predetermined threshold to detect points where a specific abnormality has occurred, and outputs a detection result.
1. An image inspection apparatus comprising an image reader that reads an original image formed on a recording material based on a print job and generates a read image, and a hardware processor that analyzes the read image and performs an image inspection,
wherein the hardware processor:
acquires the read image from the image reader, detects an edge from the read image, and excludes a region near the edge from a target of the image inspection;
performs a predetermined filter process on the read image after the exclusion process to generate a first reference image;
compares the read image after the exclusion process with the first reference image to generate a first comparison image; and
binarizes the first comparison image using a predetermined threshold to detect points where a specific abnormality has occurred, and outputs a detection result.
2. The image inspection apparatus according to claim 1 , wherein
the hardware processor detects an edge from the original image and excludes a region near the edge from the image inspection target,
performs the predetermined filter process on the original image after the exclusion process to generate a second reference image,
compares the original image after the exclusion process with the second reference image to generate a second comparison image, and
detects points where the specific abnormality has occurred, by binarizing the first comparison image using a threshold set based on the second comparison image.
3. The image inspection apparatus according to claim 1 , wherein
the hardware processor separates regions for each of the points, calculates the area of each of the regions, and excludes, from the detection result, points where the area deviates from a threshold determined according to the specific abnormality.
4. The image inspection apparatus according to claim 1 , wherein
the hardware processor separates regions for each of the points, calculates the circularity of each of the regions, and excludes, from the detection result, points where the circularity deviates from a threshold determined according to the specific abnormality.
5. The image inspection apparatus according to claim 1 , wherein when the original image includes content having a frequency component equivalent to that of the specific abnormality, the hardware processor excludes the content from the image inspection target.
6. The image inspection apparatus according to claim 1 , wherein the predetermined filter process is a process for filtering the specific abnormality.
7. The image inspection apparatus according to claim 1 , wherein the specific abnormality is an abnormality based on a firefly phenomenon.
8. An image inspection method in an image inspection apparatus including an image reader that reads an original image formed on a recording material based on a print job and generates a read image, and a hardware processor that analyzes the read image and performs an image inspection,
the image inspection method comprising:
an exclusion process for acquiring the read image from the image reader, detecting an edge from the read image, and excluding a region near the edge from a target of the image inspection;
a filter process for performing a predetermined filter process on the read image after the exclusion process to generate a first reference image:
a comparison process for comparing the read image after the exclusion process with the first reference image to generate a first comparison image; and
an abnormal point detection process for binarizing the first comparison image using a predetermined threshold to detect points where a specific abnormality has occurred, and outputting a detection result.
9. The image inspection method according to claim 8 , wherein
the exclusion process detects an edge from the original image and excludes a region near the edge from the image inspection target,
the filter process performs the predetermined filter process on the original image after the exclusion process to generate a second reference image,
the comparison process compares the original image after the exclusion process with the second reference image to generate a second comparison image, and
the abnormal point detection process binarizes the first comparison image using a threshold set based on the second comparison image to detect points where the specific abnormality has occurred.
10. The image inspection method according to claim 8 , wherein the abnormal point detection process separates regions for each of the points, calculates the area of each of the regions, and excludes, from the detection result, points where the area deviates from a threshold determined according to the specific abnormality.
11. The image inspection method according to claim 8 , wherein the abnormal point detection process separates regions for each of the points, calculates the circularity of each of the regions, and excludes, from the detection result, points where the circularity deviates from a threshold determined according to the specific abnormality.
12. The image inspection method according to claim 8 , wherein when the original image includes content having a frequency component equivalent to that of the specific abnormality, the exclusion process excludes the content from the image inspection target.
13. The image inspection method according to claim 8 , wherein the predetermined filter process is a process for filtering the specific abnormality.
14. The image inspection method according to claim 8 , wherein the specific abnormality is an abnormality based on a firefly phenomenon.
15. A non-transitory recording medium storing a computer readable program causing a computer to perform an image inspection operated in an image inspection apparatus including an image reader that reads an original image formed on a recording material based on a print job and generates a read image, and a hardware processor that analyzes the read image and performs an image inspection,
wherein the computer causes the hardware processor to perform:
an exclusion process for acquiring the read image from the image reader, detecting an edge from the read image, and excluding a region near the edge from a target of the image inspection;
a filter process for performing a predetermined filter process on the read image after the exclusion process to generate a first reference image;
a comparison process for comparing the read image after the exclusion process with the first reference image to generate a first comparison image; and
an abnormal point detection process for binarizing the first comparison image using a predetermined threshold to detect points where a specific abnormality has occurred, and outputting a detection result.
16. The non-transitory recording medium storing a computer readable program causing a computer to perform an image inspection according to claim 15 , wherein
the exclusion process detects an edge from the original image and excludes a region near the edge from the image inspection target,
the filter process performs the predetermined filter process on the original image after the exclusion process to generate a second reference image,
the comparison process compares the original image after the exclusion process with the second reference image to generate a second comparison image, and
the abnormal point detection process binarizes the first comparison image using a threshold set based on the second comparison image to detect points where the specific abnormality has occurred.
17. The non-transitory recording medium storing a computer readable program causing a computer to perform an image inspection according to claim 15 , wherein
the abnormal point detection process separates regions for each of the points, calculates the area of each of the regions, and excludes, from the detection result, points where the area deviates from a threshold determined according to the specific abnormality.
18. The non-transitory recording medium storing a computer readable program causing a computer to perform an image inspection according to claim 15 , wherein the abnormal point detection process separates regions for each of the points, calculates the circularity of each of the regions, and excludes, from the detection result, points where the circularity deviates from a threshold determined according to the specific abnormality.
19. The non-transitory recording medium storing a computer readable program causing a computer to perform an image inspection according to claim 15 , wherein when the original image includes content having a frequency component equivalent to that of the specific abnormality, the exclusion process excludes the content from the image inspection target.
20. The non-transitory recording medium storing a computer readable program causing a computer to perform an image inspection according to claim 15 , wherein the predetermined filter process is a process for filtering the specific abnormality.
21. The non-transitory recording medium storing a computer readable program causing a computer to perform an image inspection according to claim 15 , wherein the specific abnormality is an abnormality based on a firefly phenomenon.