CN110781869A - Reflection eliminating device for palm vein recognition system - Google Patents
Reflection eliminating device for palm vein recognition system Download PDFInfo
- Publication number
- CN110781869A CN110781869A CN201911155937.5A CN201911155937A CN110781869A CN 110781869 A CN110781869 A CN 110781869A CN 201911155937 A CN201911155937 A CN 201911155937A CN 110781869 A CN110781869 A CN 110781869A
- Authority
- CN
- China
- Prior art keywords
- palm vein
- palm
- infrared light
- reflection
- polarizer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V40/00—Recognition of biometric, human-related or animal-related patterns in image or video data
- G06V40/10—Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V10/00—Arrangements for image or video recognition or understanding
- G06V10/10—Image acquisition
- G06V10/12—Details of acquisition arrangements; Constructional details thereof
- G06V10/14—Optical characteristics of the device performing the acquisition or on the illumination arrangements
- G06V10/145—Illumination specially adapted for pattern recognition, e.g. using gratings
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V10/00—Arrangements for image or video recognition or understanding
- G06V10/10—Image acquisition
- G06V10/12—Details of acquisition arrangements; Constructional details thereof
- G06V10/14—Optical characteristics of the device performing the acquisition or on the illumination arrangements
- G06V10/147—Details of sensors, e.g. sensor lenses
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V40/00—Recognition of biometric, human-related or animal-related patterns in image or video data
- G06V40/10—Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
- G06V40/14—Vascular patterns
Landscapes
- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Multimedia (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Artificial Intelligence (AREA)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Vascular Medicine (AREA)
- Human Computer Interaction (AREA)
- Image Input (AREA)
- Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
Abstract
The invention relates to a reflection eliminating device for a palm vein recognition system, which comprises: the first polaroids are correspondingly arranged above the corresponding near-infrared light sources, so that near-infrared light rays emitted by the near-infrared light sources all pass through the corresponding first polaroids; and the second polaroid is arranged above the image sensor, so that light rays pass through the second polaroid before entering the image sensor, the light intensity is attenuated, and the reflection of the surface of the palm is eliminated. By adopting the reflection eliminating device, the light irradiating each position of the palm area is near infrared polarized light, and the near infrared polarized light passes through the polaroid above the image sensor before entering the image sensor, so that the effect of eliminating the reflection of the palm surface is achieved, the palm print information is filtered, only the palm vein information is reserved, the contrast ratio of the palm vein area to the non-palm vein area is improved, a clear and non-reflection palm vein image is obtained, the difficulty of an image processing algorithm is reduced, and the palm vein identification precision is improved.
Description
Technical Field
The invention relates to the technical field of remote user authentication, in particular to a light reflection eliminating device for a palm vein recognition system.
Background
Remote user authentication has become very common in today's society. The unreliability of an authentication system can cause immeasurable losses to the enterprise, especially for some remote authentication systems, the security problem is more prominent. The traditional authentication has the defects of easy forgetting, loss, sharability and the like, and the reliability of the traditional authentication cannot be guaranteed. The biometric system performs verification by using physiological or behavioral characteristics of individual characteristics, avoids the hidden danger of conventional authentication, and biometric information is difficult to copy or share.
The palm vein of a human body is hidden under the epidermis and cannot be shot under visible light, but can be shot under near infrared light, the structure is complex and is difficult to copy, in addition, the palm needs to be stretched flat when the palm vein is shot, and a hand is in a half-fist state under a natural state, so that the palm vein image cannot be stolen and shot, and the palm vein becomes a biological characteristic with high safety.
In most of the existing palm vein recognition, palm vein image acquisition is based on near infrared light irradiation acquisition, but due to reflective imaging, namely light reflected back through a palm reaches a sensor, a non-palm vein area in the palm can reflect light obviously, so that the contrast between the palm vein area and the non-palm vein area is not high, and the image processing difficulty is increased.
Aiming at the problems, the invention designs the reflection eliminating device for the palm vein recognition system, which can effectively reduce reflection and enhance image quality so as to improve recognition accuracy.
Disclosure of Invention
The object of the present invention is to overcome the above-mentioned drawbacks of the prior art and to provide a reflection-eliminating device for a palm vein recognition system, which effectively reduces reflection and enhances image quality to improve recognition accuracy.
In order to achieve the above object, the present invention provides a reflection-eliminating device for a palm vein recognition system, comprising: the reflection eliminating device comprises:
the first polaroids are correspondingly arranged above the corresponding near-infrared light sources, so that the near-infrared light rays emitted by the near-infrared light sources all pass through the corresponding first polaroids;
and the second polaroid is arranged above the image sensor, so that light rays pass through the second polaroid before entering the image sensor, the light intensity is attenuated, and the reflection of the surface of the palm is eliminated.
Preferably, the polarization direction of the second polarizer and the polarization direction of each of the first polarizers form a preset included angle.
Preferably, the polarization direction of the second polarizer and the polarization direction of each of the first polarizers form an included angle of 60 ° to 90 °.
Preferably, each of the first polarizers is combined into a polarization array, and the polarization direction of each of the first polarizers in the polarization array is the same.
Preferably, the polarization array includes at least three first polarizers, and the second polarizer is disposed in the middle of the polarization array.
Preferably, the polarization array includes four first polarizers, and the second polarizer is disposed in the middle of the polarization array.
Preferably, the polarization array is square.
Preferably, the near-infrared light source is configured to emit near-infrared light of two different wavelengths.
Preferably, the near-infrared light source is an LED lamp, and each of the LED lamps includes two sub-light sources, and the two sub-light sources are configured to emit near-infrared light of two different wavelengths.
Preferably, the first polarizer is sized to at least fully cover the corresponding near-infrared light source.
Preferably, the second polarizer is sized to entirely cover the image sensor.
Preferably, the reflection eliminating device is used for improving the contrast between a palm vein area and a non-palm vein area acquired by a palm vein identification system.
By adopting the reflection eliminating device for the palm vein recognition system, the light irradiating each position of the palm region is near infrared polarized light, and the near infrared polarized light passes through the polaroid above the image sensor before entering the image sensor, so that the effect of eliminating the reflection of the surface of the palm is achieved, the palm print information is filtered, only the palm vein information is kept, the contrast ratio of the palm vein region and the non-palm vein region is improved, a clear and non-reflection palm vein image is obtained, the difficulty of an image processing algorithm is reduced, and the palm vein recognition precision is improved.
Drawings
Fig. 1 is a schematic structural diagram of a reflection eliminating device for a palm vein recognition system according to the present invention.
Reference numerals
1 first polarizing plate
2 sub-light source
3 second polarizing plate
Detailed Description
In order to more clearly describe the technical contents of the present invention, the following further description is given in conjunction with specific embodiments.
As shown in fig. 1, a specific embodiment of a reflection-eliminating device for a palm vein recognition system is provided in the present invention, wherein the reflection-eliminating device includes: the first polaroids 1 are correspondingly arranged above the corresponding near-infrared light sources, so that near-infrared light rays emitted by the near-infrared light sources pass through the corresponding first polaroids, and are responsible for processing unpolarized light emitted by the near-infrared light sources into polarized light, so that the light vibrates along a specific direction and the light intensity is attenuated to a certain extent;a second polarizer 3 disposed above the image sensor such that light passes through the second polarizer before entering the image sensor, according to Malus' law, where the intensity of transmitted light entering the image sensor is I
l(cos θ) ^2, where I
lThe light intensity of near infrared light after passing through the polarizer array P1 is attenuated to eliminate the reflection of the surface of the palm.
The common near infrared light source always contains a great number of radiation micro-elements (atoms or molecules), and the light emitting time, vibration direction, phase and the like of each element radiator are independent of each other. Secondly, even if each individual element radiator is examined, the light it emits is not an ideal infinite wave train. Since the light emitted from the ordinary near-infrared light source is unpolarized light, the polarized light is often changed in polarization form of near-infrared light by interaction between light and a substance, and the polarizing plate of the present invention can change the unpolarized near-infrared light vibrating in various directions into polarized light vibrating in a specific direction, such as linearly polarized light, circularly polarized light, or elliptically polarized light.
The reflection eliminating device provided by the invention can be used in an image acquisition device of a palm vein recognition system, wherein the image acquisition device comprises a near-infrared imaging lens, a lens mount, a near-infrared band-pass filter, an image sensor and the like. In addition, the palm vein recognition system further includes: a light shielding tube, a light guide tube and an infrared transmission filter.
In the embodiment of the device for eliminating reflection of light for the palm vein recognition system, the polarization direction of the second polarizer and the polarization direction of each first polarizer form a preset included angle, so that the effect of eliminating reflection of light on the surface of a palm is achieved.
In an embodiment of the reflection-eliminating device for a palm vein recognition system, an included angle of 60-90 degrees is formed between the polarization direction of the second polarizer and the polarization direction of each first polarizer.
In the embodiment of the invention, in order to solve the problem of light reflection of the palm vein recognition system, the first polarizers are combined into a polarization array, and the polarization directions of the first polarizers in the polarization array are the same. The polarizer allows only vibrations parallel to the polarization direction to pass through while absorbing light vibrating perpendicular to the direction. In the polarizing plate array of the present invention, the polarizing plates are arranged in the form of fig. 1, and the polarizing directions of the four polarizing plates are the same.
In an embodiment of the reflection-eliminating device for a palm vein recognition system, the polarization array includes at least three first polarizers, and the second polarizer is disposed in the middle of the polarization array.
In an embodiment of the reflection-eliminating device for a palm vein recognition system, the polarization array includes four first polarizers, and the second polarizer is disposed in the middle of the polarization array. As shown in fig. 1, polarizer array P1: the first polarizer is arranged above the near infrared light source in an array form and comprises four first polarizers.
In an embodiment of the anti-reflection device for a palm vein recognition system provided by the invention, the polarization array is square.
In the embodiment of the reflection eliminating device for the palm vein recognition system, the near infrared light source is arranged to emit near infrared light with two different wavelengths.
In the embodiment of the reflection eliminating device for the palm vein recognition system, the near-infrared light sources are LED lamps, each LED lamp comprises two sub-light sources 2, and the two sub-light sources are arranged to emit near-infrared light with two different wavelengths.
The embodiment provided by the invention comprises 8 or more near-infrared light sources, the 8 or more near-infrared light sources are arranged into a ring-shaped light source surrounding the near-infrared imaging lens, each near-infrared light source comprises two sub-light sources, the volume of the palm vein identification system can be greatly reduced, the two sub-light sources simultaneously emit near-infrared light with different wavelengths to a living body, and the wavelength range is 780 nm-1100 nm.
In one embodiment of the anti-reflection device for a palm vein recognition system, the first polarizer is at least fully covered with the corresponding near-infrared light source.
In an embodiment of the anti-reflection device for a palm vein recognition system, the second polarizer is sized to entirely cover the image sensor.
In the embodiment of the invention, the reflection eliminating device is used for improving the contrast between a palm vein area and a non-palm vein area acquired by a palm vein recognition system.
Specifically, light emitted by the near-infrared light source irradiates a palm, the palm is irradiated by the near-infrared light, hemoglobin (including oxyhemoglobin and reduced hemoglobin) in a palm vein absorbs the near-infrared light more strongly than surrounding tissues, the light reflected by the palm is converged by a near-outer imaging lens, visible light and far-infrared light are filtered by a near-infrared band-pass filter, and reaches an image sensor, and the brightness corresponding to a palm vein region is lower than that of a non-palm vein region, so that a dark shadow (namely a palm vein image) is formed.
By adopting the reflection eliminating device for the palm vein recognition system, the light irradiating each position of the palm region is near infrared polarized light, and the near infrared polarized light passes through the polaroid above the image sensor before entering the image sensor, so that the effect of eliminating the reflection of the surface of the palm is achieved, the palm print information is filtered, only the palm vein information is kept, the contrast ratio of the palm vein region and the non-palm vein region is improved, a clear and non-reflection palm vein image is obtained, the difficulty of an image processing algorithm is reduced, and the palm vein recognition precision is improved.
In this specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.
Claims (12)
1. An anti-reflective device for a palm vein recognition system, the anti-reflective device comprising:
the first polaroids are correspondingly arranged above the corresponding near-infrared light sources, so that the near-infrared light rays emitted by the near-infrared light sources all pass through the corresponding first polaroids;
and the second polaroid is arranged above the image sensor, so that light rays pass through the second polaroid before entering the image sensor, the light intensity is attenuated, and the reflection of the surface of the palm is eliminated.
2. The device as claimed in claim 1, wherein the polarization direction of the second polarizer and the polarization direction of each of the first polarizers form a predetermined angle.
3. The device as claimed in claim 2, wherein the polarization direction of the second polarizer and the polarization direction of each of the first polarizers form an angle of 60 ° to 90 °.
4. The device of claim 1, wherein each of the first polarizers is combined into a polarization array, and the polarization direction of each of the first polarizers in the polarization array is the same.
5. The device of claim 4, wherein the polarizing array comprises at least three first polarizers, and the second polarizer is disposed in the middle of the polarizing array.
6. The device of claim 4, wherein the polarizing array comprises four first polarizers, and the second polarizer is disposed in the middle of the polarizing array.
7. The device of claim 1, wherein the polarizing array is square.
8. The device of claim 1, wherein the near infrared light source is configured to emit near infrared light of two different wavelengths.
9. The device of claim 8, wherein the near-infrared light sources are LED lamps, and each LED lamp comprises two sub-light sources, and the two sub-light sources are configured to emit near-infrared light with two different wavelengths.
10. The device of claim 1, wherein the first polarizer is sized to at least completely cover the corresponding near infrared light source.
11. The device of claim 1, wherein the second polarizer is sized to cover the image sensor entirely.
12. The device of claim 1, wherein the device is used for improving the contrast between the palm vein region and the non-palm vein region collected by the palm vein recognition system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911155937.5A CN110781869A (en) | 2019-11-22 | 2019-11-22 | Reflection eliminating device for palm vein recognition system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911155937.5A CN110781869A (en) | 2019-11-22 | 2019-11-22 | Reflection eliminating device for palm vein recognition system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110781869A true CN110781869A (en) | 2020-02-11 |
Family
ID=69392899
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911155937.5A Pending CN110781869A (en) | 2019-11-22 | 2019-11-22 | Reflection eliminating device for palm vein recognition system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110781869A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111982285A (en) * | 2020-07-22 | 2020-11-24 | 西北工业大学 | Double-blackbody infrared polarization focal plane reflected light elimination method |
| CN115793225A (en) * | 2023-01-10 | 2023-03-14 | 南京木木西里科技有限公司 | Image acquisition reflection elimination adjusting device and system thereof |
-
2019
- 2019-11-22 CN CN201911155937.5A patent/CN110781869A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111982285A (en) * | 2020-07-22 | 2020-11-24 | 西北工业大学 | Double-blackbody infrared polarization focal plane reflected light elimination method |
| CN115793225A (en) * | 2023-01-10 | 2023-03-14 | 南京木木西里科技有限公司 | Image acquisition reflection elimination adjusting device and system thereof |
| CN115793225B (en) * | 2023-01-10 | 2023-05-30 | 南京木木西里科技有限公司 | Image acquisition reflection elimination adjusting device and system thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TWI665470B (en) | System, method and apparatus for polarization control | |
| CN1145905C (en) | System for contactless recognition of hand and finger lines | |
| CN110781869A (en) | Reflection eliminating device for palm vein recognition system | |
| TWI534717B (en) | Fingerprint sensor | |
| US8494616B2 (en) | Method and apparatus for projection of subsurface structure onto an object's surface | |
| AU2004220644B2 (en) | Imaging system using diffuse infrared light | |
| WO2017115512A1 (en) | Image capture device and biometric authentication device | |
| US10474229B1 (en) | Folded viewing optics with high eye tracking contrast ratio | |
| US20160307058A1 (en) | Imaging apparatus and medical equipment | |
| KR20100123815A (en) | Imaging system using infrared light | |
| CN103584836A (en) | Real-time vein positioning and displaying device and method | |
| CN101765402A (en) | Fingerprint imaging system | |
| CN211529168U (en) | Reflection eliminating device for palm vein recognition system | |
| US20170370699A1 (en) | Reference signal filter for interferometric system | |
| US10004404B2 (en) | Portable vein projector | |
| CN207768362U (en) | Multispectral projection arrangement and multispectral photographic device | |
| WO2017086033A1 (en) | Imaging device, biometric authentication device, and semiconductor laser | |
| CN106714667A (en) | A light-based collagen measurement system and a skin treatment system | |
| US20180092539A1 (en) | Optical probe for detecting biological tissue | |
| JP2588460B2 (en) | Halation removal device for endoscopes and electronic endoscopes | |
| CN210810967U (en) | Iris blood vessel imaging system | |
| JP2008269259A (en) | Imaging module for biometrics authentication, casing, prism, and biometrics authentication apparatus | |
| JP2008527544A (en) | Biometric recognition / verification using multispectral imaging | |
| KR102663854B1 (en) | polarized lighting system | |
| CN112294256A (en) | Vein positioning projector |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |