Print inspection device, print inspection method, and program
A print inspection device includes a camera that captures a character printed on an inspection target, a shape matching processor, a deformation pattern generator, and an inspection processor. The shape matching processor checks a shape of a captured character pattern included in a captured image obtained by the camera against a shape of a preset reference character pattern while changing a deformation degree of the shape of the reference character pattern and searches for a matched character. The deformation pattern generator generates a deformed character pattern obtained by deforming the reference character pattern at the deformation degree to which the character is matched in the shape matching process. The inspection processor inspects whether a printed state of the character is satisfactory from a result of the comparison between the deformed character pattern and the captured character pattern.
1. A print inspection device that inspects a character printed on an inspection target, the print inspection device comprising:
a capturing section that captures a region of the inspection target including a portion on which the character is printed;
a shape matching processor that executes a shape matching process to check a shape of a captured character pattern included in a captured image obtained by the capturing section against a shape of a preset reference character pattern while changing a deformation degree of the shape of the reference character pattern and to search for a matched character in which a similarity of the shape of the captured character pattern to the shape of the reference character pattern is greater than or equal to a threshold value;
a deformation pattern generator that generates a deformed character pattern, the deformed character pattern being obtained by deforming the reference character pattern at a deformation degree to which the character is matched in the shape matching process; and
an inspection processor that inspects whether a printed state of the character is satisfactory from a result of comparison between the deformed character pattern and the captured character pattern.
2. The print inspection device according to claim 1 , wherein
divided reference character patterns are obtained by dividing the reference character pattern by a predetermined number of divisions, and divided character patterns are obtained by dividing the captured character pattern by the number of divisions,
the shape matching processor executes, for each of divided regions, a shape matching process to check a shape of the divided reference character pattern against a shape of the divided character pattern while changing deformation degree of the divided reference character pattern and to search for a matched divided reference character pattern in which a similarity between the shape of the divided character pattern and the shape of the divided reference character pattern is greater than or equal to a threshold value, and
the deformation pattern generator generates a divided deformed character pattern for each of the divided regions based on the deformation degree and the divided reference character pattern for each of the divided regions and generates the deformed character pattern by synthesizing the divided deformed character patterns into a single character.
3. The print inspection device according to claim 2 , wherein the number of divisions of the divided reference character patterns is individually set for each of characters.
4. The print inspection device according to claim 2 , wherein
partition lines that divide a rectangular region including the divided reference character patterns include two or more oblique partition lines that intersect a side of the rectangular region at an acute angle, and
the rectangular region is divided into three or more divisions by the partition lines including the two or more oblique partition lines.
5. The print inspection device according to claim 1 , wherein the shape matching processor changes the deformation degree by changing at least one of a size or a rotation angle of the reference character pattern.
6. The print inspection device according to claim 1 , wherein the inspection processor inspects whether the printed state of the character is satisfactory by generating an inspection region identifying image in which the deformed character pattern is overlapped with a character region including the captured character pattern in the captured image at a matching position and executing a shade inspection for a background image other than the deformed character pattern in the inspection region identifying image.
7. The print inspection device according to claim 1 , wherein the inspection processor inspects whether the printed state of the character is satisfactory by generating an inspection region identifying image in which the deformed character pattern is overlapped with a character region including the captured character pattern in the captured image at a matching position and executing a shade inspection for a region of the deformed character pattern in the inspection region identifying image.
8. The print inspection device according to claim 1 , wherein the inspection processor inspects whether the printed state of the character is satisfactory by executing a shade inspection for a combined character region, the combined character region being obtained by combining a region of the captured character pattern and a region of the deformed character pattern that are overlapped at a matching position with a character region including the captured character pattern in the captured image.
9. A print inspection method that inspects a character printed on an inspection target, the print inspection method comprising:
a capturing step that captures a region of the inspection target including a portion on which the character is printed;
a shape matching processing step that executes a shape matching process to check a shape of a captured character pattern included in a captured image obtained in the capturing step against a shape of a preset reference character pattern while changing a deformation degree of the shape of the reference character pattern and to search for a matched character in which a similarity of the shape of the captured character pattern to the shape of the reference character pattern is greater than or equal to a threshold value;
a deformation pattern generating step that generates a deformed character pattern, the deformed character pattern being obtained by deforming the reference character pattern at a deformation degree to which the character is matched in the shape matching process; and
an inspection processing step that inspects whether a printed state of the character is satisfactory from a result of comparison between the deformed character pattern and the captured character pattern.
10. A non-transitory computer readable medium storing a program executed by a computer that executes a character inspection process that inspects a character included in a target image, the program comprising: causing the computer to execute:
a shape matching processing step that executes a shape matching process to check a shape of a captured character pattern included in the target image against a shape of a preset reference character pattern while changing a deformation degree of the shape of the reference character pattern and to calculate a similarity of the shape of the captured character pattern to the shape of the reference character pattern;
a deformation pattern generating step that generates a deformed character pattern, the deformed character pattern being obtained by deforming the reference character pattern at a deformation degree to which the similarity is greater than or equal to a threshold value; and
an inspection processing step that inspects whether a printed state of the character is satisfactory from a result of comparison between the deformed character pattern and the captured character pattern.