MACHINE VISION VERIFICATION
Embodiments of systems and methods for directly reading and verifying characters on a personalized document, are provided. A surface of the personalized document is illuminated independently or simultaneously by first and second light sources. The first light source has a ring shape, surrounds the personalized document in 360 degree, and transmits a grazing incident light to illuminate the surface of the personalized document. An incident light from the second light source is reflected by a beam splitter and illuminates the surface of the personalized document in a direction generally perpendicular to the surface. Light reflected from the surface of the personalized document in a direction generally perpendicular to the surface thereof is collected by a camera.
The embodiments disclosed herein relate generally to machine vision verification, more particularly to a vision verification system for characters or symbols on a personalized document.
BACKGROUNDIn certain applications, embossed and/or indented characters, such as lines, numbers, letters, symbols, etc., on a personalized document, e.g., a credit card, need to be verified or recognized. Prior approaches used include imaging a card using a digital camera and an illumination source such as a Cloudy Day Illuminator (CDI) so that the embossed characters thereof can be verified or recognized by digitizing the image of the embossed card.
SUMMARYThe embodiments described herein relate to systems and methods for directly reading and verifying character(s) on a personalized document such as, for example, a credit card, an identification card, a gift card, a passport, etc. The embodiments provide systems and methods to illuminate the character(s) on the personalized document and directly capture an image of the character(s).
In one embodiment, the light reflected from a perimeter of the characters and that reflected from an inner portion of the characters surrounded by the perimeter, in a direction generally perpendicular to the surface of the personalized document, are different in brightness to provide a contrast. An image of the characters is captured by collecting the reflected light in the direction generally perpendicular to the surface of the personalized document. The captured image is then used to verify and/or recognize the characters on the personalized document. The characters include, for example, lines, numbers, letters, symbols, Braille, etc.
The embodiments described herein utilize at least one light source for illuminating the front side and/or the back side of the personalized document. The embodiments can reliably verify and/or recognize characters on a personalized document even if there are reflections caused by, for example, a metallic background of the personalized document, and/or characters having similar color as the background thereof.
The embodiments described herein can reliably verify and/or recognize any character on a personalized document that has a character size of, for example, 7 or 10 characters per inch (CPI) or even smaller characters. The conventional approaches using CDI may not reliably verify characters having a size of 10 CPI or less.
In addition, the embodiments can determine and analyze location and spacing of the characters to determine whether they meet standards, for example, the ISO 7811-1 standard.
In one embodiment, a vision verification system for directly reading and verifying characters on a personalized document includes at least one light source for illuminating a surface of the personalized document, and a camera for capturing an image of the characters on the surface of the personalized document. The light source is disposed with respect to the personalized document so that only light reflected from the surface of the personalized document in a direction generally perpendicular to the surface thereof is collected by the camera, and that the captured image provides a contrast between the perimeter of the characters and an inner portion of the characters defined by the perimeter.
In another embodiment, a method for directly reading and verifying characters on a personalized document is provided. The method includes illuminating a surface of the personalized document, reflecting, from a perimeter of the characters, a first amount of light in a direction generally perpendicular to the surface of the personalized document, and reflecting, from an inner portion of the characters, a second amount of light in the direction generally perpendicular to the surface of the personalized document. The second amount of light is brighter or darker than the first amount of light to provide a contrast. The reflected light is collected in the direction generally perpendicular to the surface of the personalized document to capture an image of the characters.
Referring now to the drawings in which like reference numbers represent corresponding parts throughout.
The embodiments described herein relate to systems and methods for directly reading and verifying characters on a personalized document such as, for example, a credit card, an identification card, a gift card, a passport, etc. The embodiments provide systems and methods to illuminate the characters on the personalized document and directly capture an image of the characters. The light reflected from a perimeter of the characters and that reflected from an inner portion of the characters surrounded by the perimeter, in a direction generally perpendicular to the surface of the personalized document, are different in brightness to provide a contrast. An image of the characters is captured by collecting the reflected light in the direction generally perpendicular to the surface of the personalized document. The captured image is then used to verify and/or recognize the characters on the personalized document. The characters can include, for example, embossed or indented characters, symbols, Braille, etc.
References are made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration of the embodiments in which the methods and systems described herein may be practiced. The term “personalized document” generally refers to a document having a surface with character(s) thereon that can be captured and recorded in an image. In one embodiment, the personalized document can be a card such as, for example, a credit card, an identification card, a gift card, etc. The card can include a card substrate made of, for example, a plastic material or other suitable materials. The card can also include embossed characters, symbols, Braille, etc., on a surface of the card. When embossing a character, a coloration material can be transferred from a foil onto the character. The card can also include printed material, a hologram(s), a magnetic stripe, an integrated circuit chip, etc. The personalized document can also be a passport or other travel document.
The term “embossed character” refers to a character that is indented from one side of a card and raised above the opposite surface of the card. The term “embossed character” also refers to a character that is indented into one surface of a card without being raised above the opposite surface.
The term “contrast” generally refers to the difference in brightness and/or color that makes an object (or a representation of the object in an image or display) distinguishable.
The term “camera” generally refers to a device that captures and records images. The camera can be a monochrome digital camera, a high resolution digital camera, or any suitable digital or non-digital camera.
A first light source 105 is mounted on a bracket 130 for illuminating the card 106. The first light source 105 surrounds the card 106. In the embodiment of
A second light source 109 is disposed on the side 116 of the box 110 for illuminating the card 106. The second light source 109 includes an array of LEDs that emit light through a diffuser plate 108 in a direction generally parallel to the Y axis. The diffused light transmits to a beam splitter 103. The beam splitter 103 is semitransparent and disposed about 45° with respect to the surface of the card 106. A portion of the diffused light is reflected to illuminate the surface 106a of the card 106 in a direction generally opposite the X axis. In one embodiment, about 50% of the diffused light can be reflected. The remaining portion of the diffused light transmits through the beam splitter 103 and is absorbed by the side 118. The side 118 includes a velvety felt like material 104 disposed on the surface thereof to enhance the light absorption. It is to be understood that the first and second light sources can include any suitable light sources other than LED. The light sources can be white light or monochromatic light such as red, green or blue light, or any combinations thereof.
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In one embodiment, the characters 107 can include embossed Braille characters.
The card 106 can also be illuminated by the second light source 109 shown in
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In one embodiment, up to six images can be captured by utilizing the first and second light sources 105, 109 independently or simultaneously for illuminating the characters 107 on the front and back surface of the card 106. The front surface 106a of the card 106 can be illuminated respectively by the first light source 105, the second light source 109, and simultaneously by the first and second light sources 105, 109, and three images can be captured accordingly. The card 106 then can be flipped and three images can be captured for the back surface 106b in the same manner.
In one embodiment, the three images for the front surface of the card 106 can be combined as a mixture and analyzed by an analysis tool to verify the characters.
In one embodiment, the three images for the back surface of the card 106 can be combined as a mixture and analyzed by an analysis tool to verify the characters.
It is to be understood that images of the card 106 can be taken by any sequences and/or in any combinations. The captured images are then analyzed as a mixture of combinations to verify the characters 107. This provides the ability to analyze any combination of the images in order to reach a desired threshold of confidence that the character(s) is what is expected. The desired threshold can be set at a value of 0 to 100. The higher the value of the threshold, the higher the confidence level is in the verification of the character(s). There can be a global threshold setting for scoring combination of images and there can be individual image threshold settings or a combination of global and individual threshold settings.
Images of a personalized document described herein, such as, for example, the images shown in
With regard to the foregoing description, it is to be understood that changes may be made in detail, especially in matters of the construction materials employed and the shape, size and arrangement of the parts without departing from the scope of the present invention. It is intended that the specification and depicted embodiment to be considered exemplary only, with a true scope and spirit of the invention being indicated by the broad meaning of the claims.
Claims
1. A method of directly reading and verifying a character on a surface of a personalized document, comprising:
- illuminating the surface of the personalized document including the character using a first light source that surrounds the personalized document and that transmits a grazing incident light onto the surface including the character so that first light reflects from the surface including the character, and collecting the first light reflected from the surface including the character to capture a first image of the character;
- illuminating the surface of the personalized document including the character using a second light source that transmits incident light onto the surface including the character so that second light reflects from the surface including the character, and collecting the second light reflected from the surface including the character to capture a second image of the character; and
- verifying the character by a combination of the first and second captured images.
2. The method of claim 1, wherein the grazing incident light from the first light source forms an angle of about 25° with respect to the surface of the personalized document.
3. The method of claim 1, wherein the first light source has a ring shape.
4. The method of claim 1, wherein the incident light from the second light source is reflected by a beam splitter and illuminates the surface including the character in a direction generally perpendicular to the surface.
5. The method of claim 4, wherein the first, second and third images are captured using a camera, and further comprising using a mirror that is positioned to direct the first, second and third light reflected from the surface including the character to the camera.
6. The method of claim 1, wherein the character comprises an embossed character.
7. The method of claim 1, wherein the document is a plastic card.
8. The method of claim 1, further comprising:
- simultaneously illuminating the surface including the character using the first light source and the second light source so that the grazing incident light from the first light source and the incident light from the second light source are simultaneously transmitted onto the surface including the character so that third light reflects from the surface including the character, and collecting the third light reflected from the surface including the character to capture a third image of the character; and
- verifying the character by combining the first, second and third captured images.
Type: Application
Filed: Jun 29, 2017
Publication Date: Oct 19, 2017
Inventor: Cory WOOLDRIDGE (Shakopee, MN)
Application Number: 15/637,567