TWI608376B - Method of iris recognition and iris recognition system - Google Patents

Description

Iris pattern identification method and iris pattern recognition system

The invention relates to an iris pattern recognition method and an iris texture recognition system.

The iris is a colored part of the human eye. Because each person's iris has its own individual texture, and the related features are not easy to change. Therefore, the identification of the individual identity of the iris by optical instruments is not only highly accurate, but also has a very high identification method. Fast, as long as the eyes are facing the instrument in an instant, the identification is convenient and simple.

Wearing a iris magnifying film is a very common phenomenon in modern fashion-conscious societies. However, in the iris recognition, in order to correctly identify the iris pattern, the test subject cannot wear an instrument such as an iris magnifying film that may mask the iris pattern. Therefore, if the subject is equipped with an iris magnifying film, the iris magnifying film needs to be removed before the iris recognition, which will greatly lose the convenience of iris recognition.

One aspect of the present invention is to provide an iris pattern. Identify methods and iris pattern recognition systems to enhance the convenience of iris recognition.

According to an embodiment of the invention, a method for identifying an iris texture includes the following steps. First, the subject's visible light band eye image and infrared light band eye image are intercepted. Then, the iris pattern of the subject is identified by comparing the visible light band eye image with the infrared light band eye image.

In one or more embodiments of the present invention, the visible light band eye image includes a first lens signal component, and the infrared light band eye image includes a second lens signal component and an iris signal component, the first lens signal component and the second lens signal. The component has a specific relationship. After comparing the visible light band eye image with the infrared light band eye image, the second lens signal component in the infrared light band eye image is filtered by the specific relationship, and the iris signal component is recognized by the iris signal component. The iris of the tester.

In one or more embodiments of the invention, the infrared light band eye image is an image located in the band of about 840 to 860 nm.

In one or more embodiments of the present invention, the identification method further includes the following steps. First, locate the location of the iris pattern in the infrared image of the eye. Then, by locating the distribution position of the iris pattern in the infrared light band eye image, the distribution position of the iris pattern in the visible light eye image is located.

In one or more embodiments of the present invention, the visible light band eye image and the infrared light band eye image are intercepted by different photographic angles. The identification method further includes establishing a stereoscopic eye image by using an eye image of the visible light band and an eye image of the infrared light band.

In one or more embodiments of the present invention, the identification method is further included Whether there is a boundary of the contact lens in the eye image of the infrared light band to identify whether the subject wears the contact lens.

In one or more embodiments of the present invention, an iris pattern recognition system includes a visible light source, an infrared light source, a visible light band image capture module, an infrared light band image capture module, and an identification module. The visible light source is used to illuminate the subject's eyes. An infrared light source is used to illuminate the subject's eyes. The visible light band image capture module is used to intercept the visible light band eye image of the subject. The infrared light band image capturing module is used to intercept the infrared light band eye image of the subject. The identification module is used to identify the iris pattern of the subject by comparing the visible light band image with the infrared band eye image.

In one or more embodiments of the present invention, the visible light band image capturing module includes a visible light band band pass filter and a first image sensor. The visible band bandpass filter is used to pass only visible light through the visible band bandpass filter. The first image sensor is configured to intercept the visible light band eye image formed by the visible light of the band pass filter in the visible light band. The infrared light band image capturing module comprises an infrared light band high pass filter and a second image sensor. The infrared light band high-pass filter is used to pass only infrared light through the infrared light band high-pass filter. The second image sensor is configured to intercept an infrared light band eye image formed by the infrared light of the high-pass filter in the infrared light band.

In one or more embodiments of the present invention, the filtering band of the infrared light band high pass filter is about 840 to 860 nm.

In one or more embodiments of the present invention, the facing direction of the eye defines an optical axis, and the infrared light source and the infrared light band image capturing module are adjacent to the optical axis, thereby causing the infrared light band iris pattern in the infrared light band eye image. enough Clear.

In the above embodiment of the present invention, the iris image signal component is obtained by intercepting and comparing the visible light band eye image and the infrared light band eye image of the subject, thereby filtering out the second lens signal component in the infrared light band eye image. Therefore, the iris pattern of the subject can be directly recognized without the need to remove the iris magnifying film to identify, greatly improving the convenience of iris recognition.

10, 20‧ ‧ steps

100‧‧‧Iris Pattern Identification System

110‧‧‧ Visible light source

120‧‧‧Infrared source

121‧‧‧Light source

122‧‧‧ convex lens

130‧‧‧ Visible light image capture module

132‧‧‧First image sensor

134‧‧‧Visible band bandpass filter

140‧‧‧Infrared optical band image capture module

142‧‧‧Second image sensor

144‧‧‧Infrared band high-pass filter

150‧‧‧ Identification Module

200‧‧‧ eyes

210‧‧‧瞳孔

220‧‧‧Iris

400‧‧‧ iris magnifying film

500‧‧‧Contact lenses

502‧‧‧ edge

D‧‧‧Distance

Fig. 1A is a schematic view showing the subject's eyes.

FIG. 1B is a schematic view showing the subject's eyes wearing an iris magnifying film and irradiated with visible light.

FIG. 1C is a schematic view showing the subject's eyes wearing an iris magnifying film and irradiated with infrared light.

FIG. 2 is a flow chart showing a method for identifying an iris texture according to an embodiment of the present invention.

Figure 3 is a schematic view showing the subject's eyes wearing contact lenses.

FIG. 4 is a perspective view of an iris texture recognition system according to an embodiment of the present invention.

In the following, a plurality of embodiments of the present invention will be disclosed in the drawings. For the sake of clarity, many practical details will be described in the following description. Bright. However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not necessary. In addition, some of the conventional structures and elements are shown in the drawings in a simplified schematic manner in order to simplify the drawings.

FIG. 1A is a schematic diagram showing the subject's eye 200. FIG. 1B is a schematic view showing the subject's eye 200 wearing the iris magnifying film 400 and irradiated with visible light. As shown in FIG. 1A, when performing iris recognition, the image of the eye 200 is usually intercepted first, and then the iris pattern on the iris 220 (ie, the line in the oblique line range in FIG. 1A) is intercepted for identification. However, if the subject wears the iris magnifying film 400, as shown in FIG. 1B, the iris magnifying film 400 covers the iris pattern on the iris 220 (refer to FIG. 1A), and thus the subject cannot be successfully recognized. Iris pattern.

FIG. 2 is a flow chart showing a method for identifying an iris texture according to an embodiment of the present invention. In order to solve the foregoing problems, different embodiments of the present invention provide a method for identifying an iris pattern, which is mainly suitable for identifying an iris pattern when a subject wears the iris magnifying sheet 400.

As shown in FIG. 2, step 10 is to intercept the visible light band eye image and the infrared light band eye image of the subject. Step 20 is to identify the iris pattern of the subject by comparing the visible light band eye image with the infrared light band eye image.

Specifically, as shown in FIG. 1C , the eye 200 of the subject is worn with the iris magnifying film 400 and illuminated by infrared light, since the iris 220 is located in the infrared light band, especially 850. The most obvious in the nano-band, so when the light source is in the infrared band, the iris 220 The iris pattern is not completely covered by the texture of the iris magnifying sheet 400 (the pattern on the iris magnifying sheet 400 is not explicitly drawn in Fig. 1C, and its edge is indicated only by a broken line). Thus, the infrared light band eye image of the subject will simultaneously display the iris pattern on the iris 220 and the texture on the iris magnifying sheet 400.

In contrast, as shown in FIG. 1B, when the light source is in the visible light band, the iris magnifying sheet 400 will cover the iris pattern on the iris 220, so the subject's visible light band eye image will only display the iris magnifying film. The texture on the 400.

When comparing the visible light band eye image with the infrared light band eye image, it is first determined whether the subject wears the iris magnifying film 400. It is determined that there are many methods. For example, as shown in FIG. 1C, it is detected whether the edge of the iris 220 and the edge of the iris magnifying sheet 400 are present in the eye image of the infrared light band. If both are present, the determination is determined. The iris magnifying film 400 is worn, and if only the edge of the iris 220 exists, it is determined that the subject does not wear the iris magnifying film 400.

Specifically, by detecting the number of image discontinuities in the infrared image of the infrared light band, it can be determined whether the edge of the iris 220 and the edge of the iris magnifying film 400 are simultaneously present. For example, if the pupil 210 is used as the detection starting point and the white of the eye is used as the detection end point, if three image discontinuities are detected between the detection starting point and the detection ending point (ie, between the pupil 210 and the iris 220) The image discontinuity point, the image discontinuity between the iris 220 and the eye white covered with the iris magnifying film 400, and the image discontinuity between the iris magnifying film 400 and the white of the iris that does not cover the iris magnifying film 400 are regarded as The edge of the iris 220 exists simultaneously with the edge of the iris magnifying film 400, if detected To the two image discontinuities (i.e., the image discontinuity between the pupil 210 and the iris 220 and the image discontinuity between the iris 220 and the white of the eye), it is considered that only the edge of the iris 220 exists.

Then, if it is determined that the subject is not wearing the iris magnifying film 400, the iris pattern of the subject can be recognized by a conventional method.

If it is determined that the subject is wearing the iris magnifying film 400, the position of the iris pattern in the eye image is first determined. Since the position of the edge of the iris 220 and the pupil 210 can be detected in the infrared image of the eye (which can be achieved by detecting the discontinuity of the image), the distribution of the iris in the infrared image of the eye is reflected. It will be positionable (ie, located between the outer edge of the iris 220 and the outer edge of the pupil 210 in the image).

Since the iris 220 is covered by the iris magnifying film 400 in the visible light band image, the distribution position of the iris pattern in the visible light band eye image cannot be directly located by the visible light band eye image. Therefore, by first determining the distribution position of the iris pattern in the infrared light band eye image, and then comparing the distribution position to the visible light band eye image, the distribution position of the iris pattern in the visible light eye image can be located. .

It should be noted here that when comparing the eye image of the infrared light band with the eye image of the visible light band, it is necessary to first determine a common coordinate reference point. For example, by identifying the position of the eye tail in the infrared image of the infrared light band and the visible light band, the position is used as the common coordinate reference point of the two images. Alternatively, by identifying the position of the bright spot generated by the infrared light band eye image and the eyeball reflection light source in the visible light band eye image, the position is used as a common coordinate reference point of the two images.

After determining the distribution position of the iris pattern in the eye image of the infrared light band and the eye image of the visible light band, the image of the position of the iris pattern in the infrared light band eye image and the visible light band eye image will be further analyzed and recognized. The iris of the tester.

Specifically, the visible light band eye image includes a first lens signal component, and the infrared light band eye image includes a second lens signal component and an iris signal component. Since the iris magnifying film 400 will cover the iris pattern on the iris 220 when the light source is in the visible light band, the image of the position where the iris pattern is distributed in the visible light band image is the first lens signal component, and since the light source is When the 850 nm band is used, the iris pattern on the iris 220 is not completely covered by the iris of the iris magnifying film 400. Therefore, the image of the position where the iris pattern is distributed in the infrared band image is the second lens signal component and the iris signal signal. The superposition of ingredients.

There is a specific relationship between the first lens signal component and the second lens signal component, and this specific relationship can be known by repeated tests. Specifically, the same test instrument can be used to intercept the infrared light band image of the subject when the iris magnifier 400 is worn and the iris magnifier 400 is not worn, so that the second lens signal component is compared and then compared. The specific relationship is known to the first lens signal component and the second lens signal component.

After comparing the visible light band eye image with the infrared light band eye image, the second lens signal component in the infrared light band eye image can be filtered out by the specific relationship described above, and the iris grain signal in the infrared light band eye image is known. What is the composition. Thus, the iris line signal component can identify the iris pattern of the subject.

It should be noted that, in the identification of the iris pattern of the subject, it is only necessary to intercept the image information of the position where the iris pattern in the infrared light band image and the visible light band image is distributed, and then perform the comparison. Learn about the image information of the iris pattern (ie, the iris signal component). Therefore, the first lens signal component of the visible light band eye image only contains the image information of the position where the iris pattern is distributed in the visible light band eye image, and does not include the image information of other parts of the visible light band eye image.

It should also be noted that some parts of the iris magnifying film 400 may be transparent. Therefore, before performing the filtering operation of the second lens signal component in the infrared light band eye image, the infrared light band eye image and visible light can be compared first. In the image of the position of the iris pattern in the band eye image, the same part of the two images is regarded as the portion of the iris magnifying film 400 that is set to be transparent, and the different portions of the two images are regarded as iris enlargement. The portion of the sheet 400 that is disposed at this location has a texture. Then, the filtering operation of the second lens signal component is performed only for the portions of the two images that have different textures.

By intercepting and comparing the visible light band eye image and the infrared light band eye image of the subject, the second lens signal component in the infrared light band eye image can be further filtered to obtain the iris line signal component. Therefore, the iris pattern of the subject can be directly recognized, and the iris magnifying sheet 400 can be removed for identification, thereby greatly improving the convenience of iris recognition.

Specifically, the visible light band eye image and the infrared light band eye image are simultaneously intercepted. In this way, the problem that the common coordinate reference point of the two images is difficult to determine can be avoided, and the iris state of the user can be prevented from being changed (the pupil 210 may become larger or smaller due to light, and The iris 220 will change accordingly, making it difficult to compare the visible light band eye image with the infrared light band eye image.

Specifically, the infrared light band eye image is an image located in the band of about 840 to 860 nm. It should be understood that the bands of the infrared light band eye images mentioned above are merely illustrative and are not intended to limit the present invention. Those having ordinary knowledge in the technical field of the present invention should flexibly select infrared light band eye images according to actual needs. Band.

When comparing the image of the position of the iris pattern in the visible light image of the visible light band and the infrared light band, the related image information can be converted from the right angle coordinate system to the polar coordinate system, and the second image in the infrared light band image is filtered. After the iris signal component is known by the lens signal component, the iris signal component can be converted into a two-dimensional barcode.

Specifically, the visible light band eye image and the infrared light band eye image can be intercepted by different photographic angles. Therefore, by the visible light band image and the infrared band eye image, a stereoscopic eye image can be established to further assist in identifying the subject's iris pattern. For example, by analyzing the curvature of the eyeball in the stereoscopic eye image, it can be distinguished whether the subject is wearing the iris magnifying film 400, and when the subject wears the iris magnifying film 400, the curvature of the eyeball is large, when subjected to When the tester did not wear the iris magnifying film 400, the curvature of the eyeball was small.

It should be noted that the method may further intercept at least one auxiliary eye image of the subject, and the auxiliary eye image and the infrared light band eye image and the visible light band eye image may be different or the same. Auxiliary eye images can be used to further assist in visible light imagery Alignment with the infrared image of the eye.

FIG. 3 is a schematic diagram showing when the subject's eye 200 wears the contact lens 500. As shown in FIG. 3, the method can also identify whether the subject wears the contact lens 500. Specifically, the edge 502 of the contact lens 500 displays an edge when the light source is in the infrared light band. Therefore, by detecting the number of image discontinuities in the infrared image of the infrared light band, it can be determined whether the subject is worn. The contact lens 500 (and by comparing the edge position of the iris 220 in the visible light band image with the edge position of the contact lens in the infrared light band eye image and determining whether the edge position is the same, it can be determined that the subject is wearing the iris magnifying film 400 Or contact lenses 500).

FIG. 4 is a perspective view of an iris texture recognition system 100 in accordance with an embodiment of the present invention. As shown in FIG. 4, the present embodiment provides an iris pattern recognition system 100 for performing the aforementioned identification method. The iris pattern recognition system 100 includes a visible light source 110, an infrared light source 120, a visible light band image capturing module 130, an infrared light band image capturing module 140, and an identification module 150. The visible light source 110 is used to illuminate the subject's eye 200. The infrared light source 120 is used to illuminate the subject's eye 200. The visible light band image capturing module 130 is configured to intercept the visible light band eye image of the subject. The infrared light band image capturing module 140 is configured to intercept the infrared light band eye image of the subject. The identification module 150 is configured to identify the iris pattern of the subject by comparing the visible light band image with the infrared band eye image.

Specifically, the visible light band image capturing module includes a first image sensor 132 and a visible light band band pass filter 134. The visible band bandpass filter 134 is used to pass only visible light through the visible band pass filter 134. The first image sensor 132 is configured to intercept the visible light band eye image formed by the visible light of the band pass filter 134 in the visible light band. The infrared light band image capturing module 140 includes a second image sensor 142 and an infrared light band high pass filter 144. The infrared band high pass filter 144 is used to pass only the infrared light through the infrared band high pass filter 144. The second image sensor 142 is configured to intercept an infrared light band eye image formed by the infrared light of the infrared light band high-pass filter 144.

Specifically, the filter band of the infrared light band high pass filter 144 is about 840 to 860 nm. It should be understood that the above-mentioned infrared light band high-pass filter 144 is merely an example and is not intended to limit the present invention. Those having ordinary knowledge in the technical field of the present invention should flexibly select an infrared light band high-pass filter according to actual needs. 144.

The subject defines the optical axis 102 of the iris pattern recognition system 100 in the facing direction of the eye 200 at the time of the test. In order to make the infrared light generated by the infrared light source 120 penetrate the sclera of the surface of the eyeball, the iris pattern in the infrared light band eye image is sufficiently clear, and the infrared light generated by the infrared light source 120 usually needs to have great directivity to be sufficient. Energy intensity. Under this premise, both the infrared light source 120 and the infrared light band image capturing module 140 must be adjacent to the optical axis 102, and the second image sensor 142 can receive the infrared light generated by the infrared light source 120 and reflected from the eye 200, and Forming an infrared light band eye image.

The infrared light source 120 further includes at least one light source 121 and at least one convex lens 122. The light source 121 is used to generate infrared light. The convex lens 122 is used to focus infrared light, thereby giving the infrared light a large directivity.

The iris pattern recognition system 100 has a distance D from the eye 200. The distance D may not be too small, otherwise the iris pattern recognition system 100 cannot image the eye 200, but under the premise that the iris pattern recognition system 100 can image the eye 200, the smaller the distance D, the better, so that the iris pattern recognition system 100 Information about the eye 200 that is as detailed as possible can be intercepted.

In the above embodiment of the present invention, the iris image signal component is obtained by intercepting and comparing the visible light band eye image and the infrared light band eye image of the subject, thereby filtering out the second lens signal component in the infrared light band eye image. Therefore, the iris pattern of the subject can be directly recognized, and the iris magnifying sheet 400 can be removed for identification, thereby greatly improving the convenience of iris recognition.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention can be modified and modified without departing from the spirit and scope of the present invention. The scope is subject to the definition of the scope of the patent application attached.

10, 20‧ ‧ steps

Claims (9)

An iris pattern identifying method for identifying an iris pattern of a subject wearing an iris magnifying sheet, comprising: intercepting a visible light band image of the subject and an infrared band eye image; and by comparing Identifying the iris pattern of the subject in the visible light band and the infrared light band eye image, wherein the visible light band eye image comprises a first lens signal component, and the first lens signal component is the visible light band eye image An image of a position where the iris pattern is distributed, the infrared light band eye image includes a second lens signal component and an iris grain signal component, and the second lens signal component and the iris grain signal component are superimposed as the infrared light band eye An image of a position at which the iris pattern is distributed in the image, the first lens signal component having a specific relationship with the second lens signal component, wherein the one generated by the subject when the iris is not worn is intercepted a reference infrared light band eye image and compare the infrared light band eye image with the reference infrared light The segmental eye image can know the second lens signal component, and the specific relationship can be known to the first lens signal component and the second lens signal component, in comparison to the visible light band eye image and the infrared light band eye After the image, the second lens signal component in the infrared light band eye image is filtered by the specific relationship, and the iris pattern of the subject is identified by the iris texture signal component. The identification method of claim 1, wherein the infrared light band eye image is an image located in the 840 to 860 nm band. The identification method of claim 1, further comprising: locating a distribution position of the iris pattern in the infrared light band eye image; and positioning the image by comparing a distribution position of the iris pattern in the infrared light band eye image. The location of the iris pattern in the visible light image of the eye. The identification method of claim 1, wherein the visible light band eye image and the infrared light band eye image are intercepted by different photographic angles, and further comprises: establishing, by using the visible light band eye image and the infrared light band eye image, Stereoscopic eye image. The identification method of claim 1, further comprising: determining whether the subject wears the contact lens by whether there is a boundary of the contact lens in the infrared light band image. An iris pattern recognition system comprising: a visible light source for illuminating one of the subject's eyes, wherein the eye is fitted with an iris magnifying sheet; an infrared light source for illuminating the subject's eye; a band image intercepting module for intercepting an eye image of a visible light band of the subject; An infrared light band image capturing module for intercepting an infrared light band eye image of the subject; and an identification module for identifying the visible light band eye image and the infrared light band eye image An iris pattern of the subject, wherein the visible light band image comprises a first lens signal component, wherein the first lens signal component is an image of a position where the iris pattern is distributed in the visible light eye image, and the infrared light band eye image The second lens signal component and an iris signal component are included, and the second lens signal component and the iris signal component are superimposed as an image of the position of the iris pattern in the infrared light band image, the first lens signal The component has a specific relationship with the second lens signal component, wherein a reference infrared light band eye image generated by the subject without wearing the iris magnifying film is intercepted and compared to the infrared light band eye image The reference infrared light band eye image will know the second lens signal component, and then compare the first mirror The signal component and the second lens signal component can know the specific relationship, and after filtering the eye image of the visible light band and the eye image of the infrared light band, filtering the first part of the infrared light band eye image by the specific relationship The second lens signal component is used to identify the iris pattern of the subject by the iris signal component. The iris pattern recognition system of claim 6, wherein the visible light band image capturing module comprises: a visible light band band pass filter for allowing only visible light to pass through the visible band band pass filter; and a first image sensing For capturing the visible light band eye image formed by the visible light of the visible band bandpass filter; The infrared light band image capturing module comprises: an infrared light band high-pass filter for allowing only infrared light to pass through the infrared light band high-pass filter; and a second image sensor for intercepting the high-pass band through the infrared light band The infrared light band eye image formed by the infrared light of the filter. The iris pattern recognition system according to claim 7, wherein the filter band of the infrared light band high-pass filter is 840 to 860 nm. The iris pattern recognition system of claim 6, wherein the facing direction of the eye defines an optical axis, and the infrared light source and the infrared light band image capturing module are adjacent to the optical axis, thereby causing the infrared light band to be in the eye image. The iris pattern in the infrared band is clear enough.