Coin authenticity judging method and device
AssigneeNihon Unica Corporation
InventorKunihiro Sugita
Life of this patent
Estimating the term…
Abstract
Image data of an incuse/relief portion, formed on a surface of a medal, are acquired by capturing an image of the incuse/relief portion with an image sensor, disposed so as to oppose the medal substantially straightly, while illuminating light from a light source disposed obliquely above the medal, and image processing using two or more predetermined threshold values to multinarize brightness information, including shading related to the incuse/relief portion, in the acquired image data into three or more values is performed. By the image processing of multinarization into the three or more values, the medal surface is regionally divided into at least a profile region, a top surface region, and a bottom surface region in the incuse/relief portion and compared to an authentic medal.
Claims10
A coin authenticity judging method comprising the steps of:
- acquiring image data of an incuse/relief portion, formed on a surface of a coin, by illuminating light from a light source, disposed obliquely above the coin, and meanwhile capturing an image of the incuse/relief portion by an imaging unit, disposed so as to oppose the coin substantially straightly;
- performing an image processing of using predetermined threshold values to multinarize brightness information, including shading related to the incuse/relief portion, in the acquired image data;
- and
- judging authenticity of the coin based on shape data of the incuse/relief portion, obtained by the image processing, and master data, including a shape of an incuse/relief portion formed on a surface of an authentic coin;
- and
- wherein, as the predetermined threshold values,
- two or more threshold values are set in consideration that the surface of the coin can be regionally divided into at least a profile region, a top surface region, and a bottom surface region in the incuse/relief portion,
- the multinarization is performed by quantizing the brightness information, including the shading related to the incuse/relief portion, into three or more values using the two or more threshold values, and
- the surface of the coin is regionally divided into at least the three regions by the image processing of multinarization into the three or more values.
A coin authenticity judging device comprising:
- a light source, disposed obliquely above a coin and illuminating light toward the coin;
- an imaging unit, disposed so as to oppose the coin substantially straightly and capturing an image and thereby acquiring image data of an incuse/relief portion formed on a surface of the coin;
- a master data storage unit, storing master data, including a shape of an incuse/relief portion formed on a surface of an authentic coin;
- an image processing unit, performing an image processing of using predetermined threshold values to multinarize brightness information, including shading related to the incuse/relief portion, in the image data acquired by the imaging unit;
- and
- an authenticity judging unit, judging authenticity of the coin based on shape data of the incuse/relief portion, obtained by the image processing unit, and the master data, stored in the master data storage unit;
- and
- wherein, as the predetermined threshold values,
- two or more threshold values are set in consideration that the surface of the coin can be regionally divided at least into a profile region, a top surface region, and a bottom surface region in the incuse/relief portion,
- the multinarization is performed by quantizing the brightness information, including the shading related to the incuse/relief portion, into three or more values using the two or more threshold values, and
- the image processing unit regionally divides the surface of the coin into at least the three regions by the image processing of multinarization into the three or more values.
Dependencies are inferred from the claim text.