WO2008141535A1

WO2008141535A1 - Double eyes' images acquisition apparatus using an active vision feedback mode for iris recognition

Info

Publication number: WO2008141535A1
Application number: PCT/CN2008/001161
Authority: WO
Inventors: Yucheng Wei; Rui Wang
Original assignee: Beijing Irisking Science & Technology Co., Ltd.
Priority date: 2007-05-18
Filing date: 2008-06-16
Publication date: 2008-11-27
Also published as: CN101051349B; CN101051349A

Abstract

A double eyes' images acquisition apparatus using an active vision feedback mode for iris recognition is provided. The apparatus includes a collecting unit (2) for collecting the users' iris information, which includes at least a set of optical lens and image collecting chips; a lighting unit (1) composed by apparatuses or devices externally radiating energy includes one or more lighting parts and is directly coupled to the collecting unit (2) or separated from the collecting unit (2); a feedback unit (4) including image display device, wherein the display region of the display device is divided into at least two parts, which are used to display the acquired images of the user's eyes by the collecting unit (2) respectively, so that the user can actively adjust the relative position between the eyes and the collecting unit (2) according the feed backed actual imaging effect of the eyes in the display region.

Description

Binocular image acquisition device using active visual feedback for iris recognition

The invention patent belongs to the technical field of optical devices and the field of electrical equipment, and in particular relates to an iris collection device that utilizes user self-feedback active cooperation.

Background technique

Iris recognition technology is a commonly used identification technology. The first step in its work is the acquisition of iris images. It is also a difficult step and requires comprehensive application of optical, mechanical and electrical technologies. Due to the special nature of the iris: small area (average diameter of about 11mm), the color difference between different ethnic groups is large, and the general imaging method cannot capture the iris image that can be used to identify. Iris recognition must use a lens with a higher magnification and active illumination. Westerners have a lighter iris that can be illuminated in visible light, while oriental irises have a darker color and must be illuminated by infrared light to get a clear image.

The iris image acquisition device is divided into contact type and non-contact type. The original equipment was contact-type, mainly including active lighting, lenses and accessories, and imaging chips, not necessarily with feedback devices. Contact acquisition systems typically use a cylindrical closed cavity as the housing for the collection device to isolate ambient light. A fixed focus camera is mounted at the rear end of the cylindrical cavity, and a visible light or/and an infrared light source are mounted inside the cylindrical cavity. When collecting the iris image, the user's eyes are close to the front end of the cavity, and the capture button of the camera is actively triggered to image. The advantage of this contact system is that it is easier to guide the eye, the light design is simpler, and it is not easily affected by ambient light. However, the collection device has inherent weaknesses, that is, each acquisition requires the user to be in contact with the collection device, and the contact collection also brings about a hidden danger in the health.

In order to solve the contact problem, a non-contact iris collection device has emerged, consisting of active illumination, feedback device, lens and accessories, and camera. At this time, the user has a certain distance from the iris acquisition device, such as 25cm or more. The device determines whether there is a user standing in front of the device through the ranging module or image analysis, or the device works all the time. When the device is working, it is judged whether there is an iris in the collected image, and the user is prompted to cooperate with the iris collection, and after obtaining a satisfactory image, feature extraction and comparison are performed on the iris in the image, thereby completing the identification of the user identity. The iris acquisition device evolved from the initial acquisition of a single eye device to a device that simultaneously acquired two eyes. Because it is a long-distance iris collection, and the iris area of the human eye is small, the acquisition device must use a lens with a large magnification to obtain an iris image that can be used for recognition, so that the camera captures a small angle of view, and the user must make the eye at a special At a fixed position, the position is within the depth of field of the camera, is clearly imaged, and is within the effective illumination range. It is very difficult for the user to collect the iris image with the device without any auxiliary alignment method. Therefore, various feedback devices are presented on the iris acquisition device to guide the user to achieve alignment.

Feedback devices typically use audible feedback or / and visual feedback. Auditory feedback means that the user adjusts his or her posture and position according to the voice prompts sent by the device. For example, the device will prompt “go forward, backward, left to the left, right to the right”. The auditory feedback is an active reminder to the user by the device based on information such as images acquired at the time. And visual feedback is where users adjust their position based on what they see. People have added feedback devices such as mirrors to the iris collection device to help users achieve up, down, left and right alignment in various ways. For example, Panasonic's iris recognition device requires users to see their two at the same time in the mirror of the iris recognition device. The eyes then prompt the user to move back and forth, left and right, and there is also an indicator on the device that guides the user to move. LG's iris recognition device, such as the LG3000 (monocular device), requires the user to look at the mirror so that he can see his iris in the mirrored black box, while the LG4000 (binocular iris recognition device) requires the user to see himself in the mirror. Both eyes, and a light spot transmitted behind the mirror is located in the eyebrow position of both eyes in the mirror. Products from other companies in the market, such as Iritech, OKI, etc., use similar designs. This kind of mirror-like feedback device assists the user in aligning us as passive visual feedback, because the user directly aligns according to the reflected image of the user, and the user has different eye habits, different main and auxiliary eyes, This can lead to the phenomenon that the user thinks it is aligned but the actual image is not actually captured. Currently, iris recognition products on the market are all devices that use this passive visual feedback method.

Since passive visual feedback cannot visually inform the user whether the eye position is appropriate, people continue to conduct research in this area. The US patent "Image Input Device" and the Chinese patent "non-contact self-feedback iris image acquisition device" have proposed a new type of application. Monocular iris recognition device with active visual feedback. Active feedback feeds the content captured by the camera to the user in the form of an image. The user can adjust his position like a mirror. Unlike the passive visual feedback in front, the user sees the result of the acquisition and reduces the use of the eye. With the influence of habits and the like, the alignment effect is much improved compared to the iris recognition device using passive mode visual feedback. However, the existing active adjustment methods are aimed at the monocular iris recognition technology. The user is aligned with one eye, and is likely to squint and not consciously, and because the two eyes of each person's eyes are physiologically possible and horizontal. Various angles are formed, and it is impossible to discriminate whether or not the head is tilted according to the image of one eye, thereby causing problems such as inaccurate alignment information.

Summary of the invention

In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a multi-vision rainbow using active visual feedback. Membrane collecting device, the device comprises: an collecting unit, configured to simultaneously collect iris information of two eyes of the user; the lighting unit is composed of a device or device capable of radiating energy outward, including one or more lighting parts, and the collecting unit The direct combination may also be relatively separated from the acquisition unit; the feedback unit includes a device that can display an image to the user, and the display area of the display device is divided into at least two portions for respectively displaying images of the user's eyes collected by the acquisition unit, so that The user adjusts the position of both eyes according to the image in the display area.

Preferably, the iris collection device of the present invention may further comprise a ranging unit for further prompting the user to adjust the position according to the measurement result of the ranging unit.

Preferably, the feedback unit of the present invention can not only prompt the user's position of the eye, but also emit visible light of different brightness under the control of the software to actively adjust the pupil size of the user. On the one hand, the recognition can be made more accurate, and on the other hand, false eye detection can be used to reject the forged iris. For example, the pupil size of the fake eye cannot be automatically adjusted with the light.

Preferably, the feedback unit of the present invention can also feed back information of the face at the same time to help the user to perform alignment. The acquisition unit is composed of an optical lens (group), an accessory (such as an infrared filter), and an image acquisition chip (group), and may or may not include an electric part, and may use a fixed focus lens or a zoom lens or other type. Lens. The lighting unit consists of a device or device that can radiate energy outwards, possibly one or more parts, possibly directly or in isolation from the acquisition unit. It can be, but is not limited to, LEDs, light bulbs, etc., and is not limited to infrared light, but also visible light, ultraviolet light, and the like. The feedback unit comprises a device or device that can display an image to the user, and may be one or more, and may be an LCD, a CRT, an LED array, a plasma display, a projection display, a holographic display or other display devices that are not currently available. The feedback unit can include a voice feedback part, but can also include the indicator feedback part, but is not limited to these feedback parts. The ranging unit, but can be a single physical unit, can be composed of an infrared ranging module, an ultrasonic ranging module, a laser ranging module or other types of ranging modules, or can be estimated by the software based on the characteristic changes in the acquired image. The distance from the device.

The present invention advances the alignment effect and the usability by adopting the multi-eye iris recognition system with active visual feedback. Compared with the monocular system adopting active visual feedback, the following improvements are made: more than one eye can be supported at the same time. It is more convenient and faster than the monocular system. The multi-mesh system can avoid the influence of the user's eye habits, because the use of both eyes can basically maintain the head-up, thus avoiding unconscious gimmicks and the like. Moreover, the angle of the image can be corrected according to the corners of the eyes of the two eyes, thereby greatly improving the accuracy of recognition and the speed of recognition. By simultaneously feeding back two eyes, even face information, it helps the user to align. Because people’s eyes are small, they are dedicated to The range of camera acquisition for collecting iris images is relatively small. For example, in a single-eye system self-feedback system, the user may feel inconvenient when using only the range for alignment, and more information is more effective for alignment prompts.

Compared with all current binocular devices, the present invention has the following improvements: The existing binocular devices are all aligned using a mirror-like feedback device, which causes the user to think that they are aligned but actually cannot obtain a suitable image. phenomenon. The device of the present invention directly feeds back the two eyes collected by the acquisition system, and even the face information to the user, which helps the user to perform alignment, and the alignment speed is 3 to 5 times higher than that of the existing binocular device. In the present invention, our feedback unit can simultaneously emit a controllable light adjustment for the user's pupil size. The feedback unit can not only prompt the user's position of the eye, because the user annotates the feedback unit when using the device, and the change of the light and brightness of the feedback unit directly stimulates the user to change the pupil of the user, and the visible light of different brightness is actively controlled by the software. Adjust the pupil size of the user. On the one hand, it can make the recognition more accurate, on the other hand, it can also be used for false eye detection to reject the forged iris. For example, the pupil size of the fake eye cannot be automatically adjusted with the light.

DRAWINGS

1 shows a schematic diagram of a multi-eye iris acquisition device employing active visual feedback in accordance with one embodiment of the present invention;

Figure 2 shows a view of a feedback unit in accordance with one embodiment of the present invention;

Figure 3 illustrates another view of a feedback unit in accordance with one embodiment of the present invention;

Figure 4 illustrates another view of a feedback unit in accordance with one embodiment of the present invention;

Figure 5 shows a schematic diagram of a multi-eye iris acquisition device employing active visual feedback in accordance with another embodiment of the present invention;

Figure 6 shows a view of a feedback unit in accordance with another embodiment of the present invention;

Figure 7 shows a schematic diagram of a multi-eye iris acquisition device employing active visual feedback in accordance with another embodiment of the present invention. detailed description

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Embodiment 1 :

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view of a first embodiment of the present invention. Referring to FIG. 1, the illumination unit 1 is located around or beside the acquisition unit 2 for illuminating the iris 3 of the eye. Since the illumination unit 1 has a certain emission angle, the feedback unit 4 has a certain observation angle, and the acquisition unit 2 also has a certain collection. Angle and depth of field range, adjust the illumination unit 1 to collect the optical axis of the unit 2 and the feedback unit 4 so that it can be in a space that is at a certain distance from the device (called the identifiable space volume). Can meet the following requirements:

1. The user can clearly see the feedback display unit 4 in the range.

2. The lighting unit 1 can illuminate the user's iris with suitable energy 3

3. The acquisition unit 2 can clearly collect the iris image of the user and obtain an image that meets the collection requirements.

The device uses the illumination unit 1 to illuminate the user's iris 3 while capturing the user's iris image, and directly feeding the collected content to the user on the feedback unit 4 to guide the user to perform positioning. At the same time, more information can be collected, such as not only displaying the user's eyes, but also displaying the user's face, which further facilitates user alignment. The image displayed on the feedback unit 4 may be an image processed image or an original image obtained without image processing. At the same time, the feedback unit 4 may sound to prompt the user.

Since iris recognition can only be done in an identifiable volume of space, the user's unknowns are easy to align after using the active visual feedback device, but the front and rear positions are difficult to determine without a clear reference. This is used in our system. The ranging unit 5 helps the user to locate this situation. When the feedback distance of the ranging unit 5 is not appropriate, the feedback unit 4 (image/indicator/speech, etc.) is notified to move the user back and forth, and the image displayed by the feedback unit 4 can be blurred, so that the user actively moves forward and backward. A variety of methods are used in combination to achieve better ease of use.

The software can control the intensity of the visible light emitted by the feedback unit 4. Since the human eye is sensitive to visible light, the pupil is adjusted according to the visible light illumination, and according to this characteristic, the size of the pupil when the pupil is close to registration can be adjusted on the one hand to reduce the size of the pupil. The pupil change causes the effect of nonlinear changes in the iris texture. On the other hand, it is also possible to perform a living iris detection based on the change of the pupil to avoid false forging of the iris such as a false eye. The intensity of the visible light emitted by the feedback unit 4 can be achieved by controlling the brightness of the display portion of the feedback unit 4, or / and the indicator portion or / and other portions.

In Fig. 1, the acquisition unit 2 is located below the feedback unit 4, and the acquisition unit 2 is composed of a fixed focus lens, an infrared CCD camera head, and an infrared filter. The fixed focal length of the lens is 30mm and the object distance is 30cm. The CCD camera adopts a N-channel 600-line infrared camera, and the output video signal is transmitted to the host computer through the video capture card. The feedback unit 4 is a small LCD display with a resolution of 640 X 480, facing the user. The LCD is driven by a host computer through a separate graphics card. The illumination unit 1 is located on both sides of the feedback unit 4, and the illumination unit 1 is composed of an infrared LED array. The intensity of the LED lamp can be controlled by software, and the infrared illumination light emitted by the illumination unit 1 can be irradiated to the eyes of the user. The ranging unit 5 is composed of an infrared ranging module and is located below the collecting unit 2. The optical unit of the illumination unit 1, the feedback unit 4 and the acquisition unit 2 intersect at a position 20, 30 cm in front of the feedback unit 4.

The specific work flow is as follows: When there is no user in front of the iris collecting device, the distance measuring unit 5 judges that there is no one in front. The iris acquisition device does not work. Before the user walks to the iris collecting device, the distance measuring unit 5 determines that there is a person in front, the iris collecting device starts to work, the iris collecting device controls the lighting unit 1 to emit infrared light, and the iris collecting device determines whether the user stands according to the result of the infrared ranging unit 5 Within the range allowed to be recognized, if yes, the image is collected, otherwise the host prompts the user to move back and forth through the feedback unit 4 (such as "Please move forward/backward" on the LCD). When the user is within the range allowed to be recognized, the host displays the collected content on the LCD of the feedback unit 4 by the iris collecting device. As shown in FIG. 2, the middle portion of the LCD is divided into two areas for respectively displaying the user. The left and right eyes of the LCD can also be used to display the user's face or other prompt text. The user can see the two eyes and the corresponding part of the face in the middle of the screen. The user can adjust the position of the up, down, left and right according to the content displayed on the screen, so that his eyes appear completely in the screen. The host judges the quality of the iris image collected and controls the light intensity of the infrared illumination to make the illumination most suitable.

Here, the user faces the LCD screen of the feedback unit 4, and the acquisition unit 2 collects the iris image of the user from below the feedback unit 4. The lighting unit 1 is illuminated from both sides. An example of the LCD screen is shown in Figure 2-4. If the user sees similar figure 2, it will automatically move to the left. If you see Figure 3, it will automatically move to the upper right. If you see similar figure 4, it will automatically turn around. At the same time, the algorithm can also perform angle correction according to the angle of the eyes of both eyes.

At the same time, the host also controls the color and brightness of the display content of the upper half of the LCD of the feedback unit 4, so that the size of the pupil of the user changes, and the living body is detected. In the process, the identity of the user is confirmed according to the iris image collected from the user.

Since the images of the two eyes can be obtained at the same time, the user can generally maintain the head-up. Even if the user turns the head, the algorithm can correct the angle of the image according to the corners of the eyes of the two eyes, thereby greatly improving the recognition accuracy and the recognition speed. After the iris recognition is completed, the recognition result is displayed on the LCD of the feedback unit 4.

Embodiment 2: Fig. 5 shows a schematic view of another embodiment of the present invention. As shown in FIG. 5, the collecting unit 2 is facing the eyes of the user, and the collecting unit 2 is composed of a fixed focus lens, an infrared CCD camera, an infrared filter and a half mirror 6. The fixed focal length of the lens is 30mm and the object distance is 30cm. The CCD camera adopts a N-line 600-line infrared camera, and the output video signal is transmitted to the host through the video capture card. The half mirror 6 transmits infrared light and reflects all visible light. An image of the user's eyes can be acquired through the half mirror 6, and the content displayed by the feedback unit 4 does not affect the captured image. The feedback unit 4 is a small CRT display with a resolution of 640 X 480 at an angle of 90 degrees to the viewing direction of the user. The display content of the feedback unit 4 is projected to the user through the half mirror 6. Lighting unit 1 is located in the acquisition unit On both sides, the lighting unit 1 is composed of an infrared LED array, and the illumination intensity is not adjustable. The infrared illumination light emitted by the illumination unit 1 can be illuminated to the eyes of the user, and the ranging unit 5 is composed of an infrared ranging module located below the acquisition unit 2 (not shown). The optical axes of the illumination unit 1, the feedback unit 4 and the acquisition unit 2 intersect at a position 20 to 30 cm in front of the feedback unit 4. The specific workflow is as follows: When there is no user in front of the iris acquisition device, the distance measurement unit 5 determines that there is no one in front, the iris The acquisition device does not work. When a user walks to the iris collection device, the distance measuring unit 5 judges that there is a person in front, and the iris collection device starts to work. The iris acquisition device controls the illumination unit 1 to emit infrared light to illuminate both eyes of the user. The iris collecting device judges whether the user stands within the range allowed for recognition according to the result of the infrared ranging unit 5, and if so, starts collecting images, otherwise the host prompts the user to move back and forth through the feedback unit 4 (such as displaying on the CRT) Move back "). When the user is within the range allowed to be recognized, the host displays the collected content on the CRT of the feedback unit 4 by the iris collecting device, and the user can see that the two eyes and the face of the eyes are observed in the middle of the screen. In the corresponding part of the department, the user can adjust the position of the up, down, left, and right according to the content displayed on the screen, so that his eyes are completely displayed on the screen. At the same time, the host also controls the color and brightness of the display and content of other parts of the CRT of the feedback unit 4, so that the size of the pupil of the user changes, and the living body detection is performed. In the process, the identity of the user is confirmed according to the iris image collected by the user. After the iris recognition is completed, the recognition result is displayed on the CRT of the feedback unit 4.

Here, the user faces the lens of the acquisition unit 2 while observing the iris image of the user obtained by the acquisition unit 2 from the half mirror 6. The lighting unit 1 is illuminated from both sides. The image that the user sees at this time is similar to that shown in Figure 6. Implementation 3:

Fig. 7 shows a schematic view of another embodiment of the invention. In this embodiment, iris information for both eyes can be acquired with only one set of optical lens and image collection chip. As shown in FIG. 7, the acquisition unit 2 is composed of a fixed focus lens, an infrared CMOS camera chip, an infrared filter, a mirror 7 and a half mirror 6, and is passed through the half mirror 6 in the acquisition unit 2. It transmits infrared light and reflects all visible light. The image of the user's eye is projected to the mirror 7, and by controlling the rotation of the mirror 7, the acquisition unit 2 realizes time-division of the user's eyes. Under the rapid rotation of the mirror 7, the system acquisition speed can reach 540 per eye per eye. frame.

The feedback unit 4 is a small CRT display with a resolution of 640 X 480 at an angle of 90 degrees to the viewing direction of the user. The display content of the feedback unit 4 is projected to the user through the half mirror 6. The lighting unit 1 is located on both sides of the collecting unit 2, and the lighting unit 1 is composed of an infrared LED array, and the illumination intensity can be adjusted. The infrared illumination light emitted by the illumination unit 1 can be illuminated In the eyes of the user, there is no physical ranging unit in this embodiment, and the distance between the user and the collecting device is estimated by an algorithm. The optical axes of the illumination unit 1, the feedback unit 4, and the collection unit 2 intersect at a position 3040 cm in front of the feedback unit 4.

The specific work flow is as follows: When there is no user in front of the iris collection device, the image is judged to be in front of the person, and the iris collection device does not work. When a user walks to the iris collection device, the person in front of the image is judged by the image, and the iris collection device starts working. The iris acquisition device controls the illumination unit 1 to emit infrared light to illuminate the user's eyes. The iris collecting device judges whether the user stands within the range allowed for recognition according to the result of the infrared ranging unit 5, and if so, starts quality judgment and analysis on the collected image, otherwise the host prompts the user to move back and forth through the feedback unit 4 (such as in the CRT) "Please move forward/backward" is displayed on the screen. When the user is within the range allowed to be recognized, the host displays the collected content on the CRT of the feedback unit 4 by the iris collecting device, and the user can see that the two eyes and the face of the eyes are observed in the middle of the screen. In the corresponding part of the department, the user can adjust the position of the up, down, left, and right according to the content displayed on the screen, so that his eyes are completely displayed on the screen. The host simultaneously controls the light intensity of the infrared illumination unit 1 to make the illumination most suitable. At the same time, the host also controls the color and brightness of the display content of other parts of the CRT of the feedback unit 4, so that the pupil size of the user changes, and the living body detection is performed. In the process, the identity of the user is confirmed according to the iris image collected by the user. After the iris recognition is completed, the recognition result is displayed on the CRT of the feedback unit 4.

Here, the user observes his own iris image obtained by the acquisition unit 2 from the half mirror 6. The lighting unit 1 is illuminated from both sides. At this time, the image seen by the user is similar to that shown in Figure 6.

In the above several embodiments, the fixed focus lens is changed to the zoom lens, and the illumination part can automatically rotate according to the calculated user position, the different positions of the distance measurement module or the combination of different ranging methods can be composed. New implementation plan. A person skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention.

Claims

Claim

1. A multi-eye iris acquisition device using active visual feedback, comprising:

The acquisition unit (2) comprises at least one set of optical lens and image acquisition chip for collecting iris information of the user; the illumination unit (1) is composed of a device or device capable of radiating energy outward, including one or more illuminations In part, it may be directly combined with the acquisition unit (2) or the acquisition unit (2) may be relatively separated; and a 'feedback unit (4), including a device that can display an image to the user, a display area of the display device, for displaying the The acquisition unit (2) collects an image of the user's eyes so that the user actively adjusts the relative position between the eye and the acquisition unit (2) according to the actual imaging effect of the eye fed back in the display area.

2. A multi-eye iris acquisition device using active visual feedback according to claim 1, further comprising a ranging unit (5) for further prompting the user to adjust the position based on the result of the measurement by the ranging unit (5).

3. A multi-eye iris acquisition apparatus using active visual feedback according to claim 1 or 2, wherein the acquisition unit (2) comprises a motorized portion, using a fixed focus lens, a zoom lens or other type of lens.

4. A multi-eye iris acquisition device using active visual feedback according to claim 1 or 2, wherein the illumination unit (1) comprises LEDs, light bulbs, infrared, visible light and ultraviolet illumination fixtures. ·

A multi-eye iris acquisition apparatus using active visual feedback according to claim 1 or 2, wherein the feedback unit (4) comprises an LCD, a CRT, an LED array, a plasma display, a projection display, and a holographic display.

6. The multi-eye iris collecting device adopting active visual feedback according to claim 5, wherein the feedback unit (4) emits visible light of different brightness and color to actively adjust the pupil size of the user, thereby realizing the living body detection for the user's eyes. .

7. A multi-eye iris acquisition device using active visual feedback according to claim 5, wherein the feedback unit (4) also feeds back information of the face to assist the user in aligning.

8. A multi-eye iris acquisition device using active visual feedback according to claim 2, wherein the ranging unit (5) uses an infrared ranging module, an ultrasonic ranging module, a laser ranging module or other types of ranging The module, or software, estimates the distance between the user and the device based on changes in features in the acquired image. ·

9. A multi-eye iris acquisition device using active visual feedback according to claim 1, wherein the feedback unit (4) further comprises an acoustic feedback device for prompting the user to adjust the position.