KR101551427B1 - Mobile terminal for supporting iris recognition function - Google Patents

Abstract

A camera module of a compact size used in a mobile terminal includes a dual bandpass filter capable of actively selecting an image of a visible light region and an image of an infrared region between a lens and an image sensor, So that a high quality general image or iris recognition image can be freely obtained.
As a form for realizing this, the present invention provides a mobile terminal supporting an iris recognition function, comprising: a battery unit 110 for supplying power to the mobile terminal; A memory unit 130 for storing an iris recognition program implementing the iris recognition function; A touch screen unit 140 for sensing a touch command of the user regarding the iris recognition function and displaying a processing result of the touch command; A camera module unit (150) configured to acquire an image of a subject including an iris; A communication unit 160 for performing a communication function with another terminal through a mobile communication network; And a control unit (170) for driving the iris recognition program in response to detection of a user's touch command regarding the iris recognition function, wherein the camera module unit (150) A wavelength separating mirror part 152 capable of separating light of a high wavelength and light of a low wavelength among the light collected through the lens part 151, An iris recognition filter 153a for transmitting only light having a wavelength of 800 nanometers or more in the high wavelength light transmitted from the wavelength separating mirror 152; A general image filter unit 153b that transmits only light having a wavelength of less than a nanometer or less and a photoelectric converter 153b that photoelectrically converts light that has passed through the iris recognition filter unit 153a or the general image filter unit 153b, To about comprises a digital signal or an image sensor 154 which outputs a digital signal on the common image provides a mobile terminal configured.

Description

[0001] MOBILE TERMINAL FOR SUPPORTING IRIS RECOGNITION FUNCTION [0002]

The present invention relates to a mobile terminal having a camera module capable of recognizing an iris, and more particularly, to a camera module of a compact size used in a mobile terminal, in which an image of a visible light region and an image of an infrared region The present invention relates to a mobile terminal capable of freely acquiring a general image or iris recognition image of high quality according to a mode of a mobile terminal by providing a dual bandpass filter which can actively select the image.

In general, the camera module for a mobile terminal is very small in size, and has a wide variety of applications such as a PDA, a smart phone, and a toy camera.

Such a camera module for a mobile terminal is manufactured by using an image sensor chip of CCD or CMOS, and the object can be displayed on a display medium such as a PC monitor or an LCD display device by focusing an object through a lens on an image sensor chip FIG. 1 is a schematic block diagram of a conventional camera module for a mobile terminal.

1, since the conventional camera module 100 for mobile terminals is designed for the purpose of capturing an image in a visible light, an infrared cut filter 8 (see FIG. 1) is provided between the lens L and the image sensor 2, Is configured to block the infrared ray of an excessively long wavelength flowing into the image sensor 2.

However, when such a conventional camera module is used, there is a problem that it can not support various authentication functions through biometric recognition (for example, iris recognition) at all.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a compact camera module for use in a mobile terminal in which an image of a visible light region and an image of an infrared region are actively selected The present invention provides a mobile terminal capable of freely acquiring a high quality general photographic image or an iris recognition image according to a mode of a mobile terminal by providing a dual bandpass filter as much as possible.

According to another aspect of the present invention, there is provided a mobile terminal supporting an iris recognition function, including: a battery unit for supplying power to the mobile terminal; A memory unit for storing an iris recognition program implementing the iris recognition function; A touch screen unit for sensing a touch command of the user relating to the iris recognition function and displaying a processing result of the touch command; A camera module configured to acquire an image of a subject including an iris; A communication unit for performing a communication function with another terminal through a mobile communication network; And a control unit for driving the iris recognition program in response to sensing a user's touch command regarding the iris recognition function, wherein the camera module unit comprises: a lens unit for collecting reflected light from a subject including the iris; A wavelength separating mirror unit capable of separating the light collected through the lens unit into light having a high wavelength and light having a low wavelength; and a light separating unit separating only light having a wavelength of 800 nanometers or more from the high wavelength light transmitted from the wavelength separating mirror unit A general image filter unit for transmitting only light having a wavelength of 650 nanometers or less in the light of the low wavelength transmitted from the wavelength separation mirror unit; The light passing through the image filter section is photoelectrically converted into a digital signal relating to the iris image or a general image It provides a mobile terminal comprising an image sensor portion for outputting the digital signal.

According to a preferred embodiment, the mobile terminal may further include an infrared LED capable of irradiating an object including the iris with infrared light having a wavelength of 800-900 nanometers.

According to a preferred embodiment, the wavelength-separating mirror section may be constituted by a dichroic mirror.

According to a preferred embodiment of the present invention, the wavelength-separating mirror portion is formed by passing light having a wavelength of 700 nanometers or more as light of the high wavelength and reflecting light having wavelengths of less than 700 nanometers as light having the low wavelength, It can be configured as a mirror.

According to a preferred embodiment of the present invention, the iris recognition program causes the control unit to perform the steps of: (a) determining whether the current state of the mobile terminal is the iris capture mode or the general image capture mode; (b) when the current state is the iris photographing mode, driving the infrared LED; (c) the image sensor section photoelectrically converts only light acquired by the iris recognition filter section; (d) instructions for automatically tracing the pupil position in the acquired iris image.

According to a preferred embodiment, the automatic tracing of the pupil position in the acquired iris image (d) comprises: (d1) analyzing a histogram of the image of the iris among the images captured through the image sensor unit; (d2) converting the image of the iris into a binarized binary image based on a threshold value obtained by analyzing the histogram; (d3) extracting only the binary image of the pupil by removing noise from the transformed binary image; (d4) extracting the center coordinates of the pupil using a binary image of the pupil; (d5) instructing to generate an iris code unique to the individual by analyzing the pattern of the image of the iris based on the center coordinates of the pupil by predetermined regions.

1 is a view for explaining a camera module applied to a conventional mobile terminal.
2 is a block diagram illustrating a configuration of a mobile terminal supporting an iris recognition function according to the present invention;
3 is a block diagram illustrating a configuration of a camera module unit applied to the mobile terminal of FIG.
4 is a view showing an example of an infrared LED applied to the mobile terminal of FIG. 2;
Fig. 5 is a flowchart schematically showing one algorithm of an "iris recognition program" applied to the mobile terminal of Fig. 2;
Fig. 6 is a flowchart schematically showing another algorithm of the "iris recognition program" applied to the mobile terminal of Fig. 2;
7A is a diagram showing a histogram of an image of an iris calculated by the "iris recognition program ".
7B is a diagram showing a binary image obtained by binarizing an image of an iris by an "iris recognition program ".
7C is a diagram showing a binary image of a pupil calculated by the "iris recognition program ".
7D is a diagram for explaining a process of calculating the center of the pupil by the "iris recognition program ".
7E is a diagram showing the center of the pupil calculated according to the "iris recognition program ".

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail below with reference to the accompanying drawings.

FIG. 2 is a block diagram illustrating a configuration of a mobile terminal 1 supporting an iris recognition function according to an embodiment of the present invention. FIG. 3 is a block diagram illustrating a configuration of a camera module 150 applied to the mobile terminal 1. Referring to FIG. Block diagram.

Referring to FIG. 2, the mobile terminal 1 supporting the iris recognition function according to the present invention is a terminal capable of implementing the iris recognition function together with the voice call function.

The mobile terminal 1 supporting the iris recognition function according to the present invention includes a battery unit 110, a key input unit 120, a memory unit 130, a display unit 140, a camera module unit 150, A communication unit 160, and a control unit 170. In addition, the mobile terminal 1 supporting the iris recognition function according to the present invention may further include an infrared LED 180 (see FIG. 4) capable of irradiating the subject with infrared light having a wavelength of 800-900 nanometers.

The battery unit 110 functions to supply power to the mobile terminal 1 supporting the iris recognition function.

The key input unit 120 may include one or more buttons including a button for generating a key signal for operating various functions including an iris recognition function.

The memory unit 130 includes a protocol for performing a voice call function of the mobile terminal 1 supporting the iris recognition function, a program for performing the iris recognition function, and various protocols for performing the ancillary functions of the mobile terminal 1. [ And a storage means for storing the conversion program.

The memory unit 130 may include at least one event information generated through the key input unit 120 and the touch screen unit 140 of the mobile terminal 1, Temporarily stores intermediate data related to various iris recognition processes.

The touch screen unit 140 is a screen for detecting touches on specific positions of numbers, characters, symbols, or icons displayed on the display screen and performing an operation process corresponding to the touches. That is, the touch screen unit 140 may include various functions of the mobile terminal 1 such as iris recognition function, iris processing function, voice call function, web surfing function, search function, quick menu selection function, Function as an input unit.

The camera module unit 150 is a device capable of capturing high-quality general images and iris images. 3, the camera module unit 150 includes a lens unit 151 for collecting reflected light from an object including an iris, and a lens unit 151 for picking up light of high wavelengths An iris recognition filter unit 152 for transmitting only light having a wavelength of 800 nanometers or more in the high wavelength light transmitted from the wavelength separation mirror unit 152, A general image filter unit 153b for transmitting only light having a wavelength of 650 nanometers or less in the light of a low wavelength transmitted from the wavelength separation mirror unit 152 and a filter unit 153b for filtering the iris recognition filter unit 153a or 153b. And an image sensor 154 for outputting a digital signal relating to the iris image or a digital image relating to the general image by photoelectrically converting light passing through the general image filter unit 153b.

According to a preferred embodiment, the wavelength-separating mirror portion 152 can be constituted by a dichroic mirror that transmits light having a wavelength of 700 nanometers or more and reflects light having a wavelength of less than 700 nanometers.

According to a preferred embodiment, when the mode of the mobile terminal 1 is in the iris recognition mode, the image sensor unit 154 outputs only the light that has passed through the iris recognition filter unit 153a according to a control command of the controller 170 And when the mode of the mobile terminal 1 is in the normal image photographing mode, photoelectric conversion is performed only on light passing through the general image filter unit 153b.

The control unit 170 controls the iris recognition program 131 stored in the memory unit 130 according to an operation start signal of the camera module 150 from the key input unit 120 or the touch screen unit 140 And performs iris recognition processing or general image processing operations.

FIG. 5 is a flowchart schematically showing one algorithm of the iris recognition program 131 applied to the mobile terminal 1. FIG.

5, the iris recognition program 131 applied to the mobile terminal 1 allows the control unit 170 to determine whether the current state of the mobile terminal 1 is the iris imaging mode or the general imaging mode (S401, S405); Driving the infrared LED 180 when the current state is the iris photographing mode (S402); A step S403 of causing the image sensor unit 154 to photoelectrically convert only the light acquired by the iris recognition filter unit 153a; And performing an iris recognition process including an operation of automatically tracking the pupil position in the acquired iris image (S404).

The iris recognition program 131 applied to the mobile terminal 1 according to the present invention may further include a step of causing the control unit 170 to disable the infrared LED 180 when the current state is the general image photographing mode S406); A step S407 of causing the image sensor unit 154 to photoelectrically convert only light acquired by the general image filter unit 153b; And performing the process of the acquired general image (S408).

The control unit 170 calls the iris recognition program 131 stored in the memory unit 130 again or continues to drive the iris recognition program 131 to determine the pupil position in the iris image acquired from the image sensor unit 154 An automatic tracking operation can be performed.

FIG. 6 is a flowchart schematically showing another algorithm of the iris recognition program 131 applied to the mobile terminal 1. FIG.

6, the iris recognition program 131 applied to the mobile terminal 1 according to the present invention causes the control unit 170 to generate an iris image for causing an image of the iris captured through the camera module 150 to be retrieved, Calling step 404a; A histogram analyzing step (S404b) of analyzing a histogram of the image of the iris; A binary image transforming step (S404c) of transforming the image of the iris into a binarized binary image on the basis of the threshold value obtained through the histogram analyzing step; A pupil image extracting step (S404d) of extracting only a binary image of a pupil by removing noise from the binary image obtained through the binary image transforming step; A pupil center coordinate extraction step (404e) for extracting a center coordinate of the pupil using the binary image of the pupil obtained in the pupil image extraction step; And a step (not shown) of generating an iris code unique to a person by analyzing the pattern of the image of the iris based on the pupil center coordinates for each predetermined region.

Hereinafter, with reference to FIG. 7A to FIG. 7E, details of each detail step of the algorithm of the iris recognition program 131 described with reference to FIG. 6 will be described.

(Histogram analysis step S404b)

The iris recognition program 131 performs an operation of analyzing the histogram of the iris image captured through the camera module 150.

For example, the image of the iris obtained through the camera module 150 is a monochrome image having 8-bit color information. Therefore, each pixel has an intensity value of 0 to 255.

The iris recognition program 131 first performs an operation of calculating histogram data, which is pixel density information, in order to perform the process of the histogram analysis step S404b. For reference, a histogram refers to a distribution of intensity (intensity) values for pixels in an image. For example, in a 256 gray level image, the histogram value range of the histogram is from 0 to 255, and the frequency of each intensity value is examined to show the height of the graph.

Next, the iris recognition program 131 performs an operation of determining a predetermined threshold value from the histogram data.

7A shows a histogram of the iris image calculated by the iris recognition program 131. FIG. Here, the portion denoted by A represents a threshold value determined by the iris recognition program 131. [

For example, in the histogram of FIG. 7A, one peak is formed in a portion having a small brightness value (pupil) and a pattern in which three or more peaks are formed at a high brightness value. Therefore, Respectively.

(Binary image conversion step S404c)

Next, the iris recognition program 131 performs an operation of converting the iris image into a binarized binary image on the basis of the threshold value obtained through the histogram analysis step S404b.

In order to perform the process of transforming the binary image (S404c), the iris recognition program 131 may set the threshold value to 0 when the pixel density value is smaller than the threshold value based on the threshold value obtained in the histogram analysis step (S404b) If the pixel density value is large, the process is performed by setting the value to 255.

For example, if the pixel density value of the (x, y) coordinate is p (x, y) and the threshold value is T, the iris recognition program 131 calculates Pixel density value of the pixel.

(1)

(One)

7B shows a binary image obtained by binarizing the image of the iris according to the binary image transforming step S404c.

(Pupil image extraction step S404d)

Next, the iris recognition program 131 performs an operation of extracting only the binary image of the pupil through the process of removing noise from the binary image obtained through the transformation of the binary image (S404c).

As shown in FIG. 7B, the binarized image of the binarized iris through the binary image transforming step S404c includes not only pupil but also eyebrows and noise due to the reflected image. Accordingly, the iris recognition program performs the following steps a1 to a5 on the binary image of the iris while scanning the right side and the top side from the outside.

(a1)

(x, y-1) pixels on the left (x-1, y) and upper (x, y-1)

If only one of the two neighboring pixels has a label, the label is given to the (x, y) pixel.

If two neighboring pixels have the same label, the label is given to the (x, y) pixel.

(a2)

If neighboring pixels have different labels, label the upper neighbor pixel and label the two labels in the equivalent table with an equivalent label. If the two neighboring pixels do not have a label, a new label is given and the label is written to the equivalent table. An equivalent label is a different label for the connected components. A set of these equivalent labels is called an equivalence set, and a set of equivalence sets is called an equivalence table.

(a3)

If there are pixels which are not labeled, the process goes to step (a1).

(a4)

Find the lowest label for each equivalent set in the equivalence table.

(a5)

Investigate the image and change each label to the lowest label in the equivalent set.

The algorithm including (a1) through (a5) above requires two investigations on the binary image of the entire iris. In the first study, partial regions are obtained and connectivity between partial regions is identified (steps a1 to a3). In the second investigation, equivalent labels are inspected and re-labeled (steps a4 to a5).

The label with the largest number of pixels among the labeled connected components is the pupil. Therefore, the "iris recognition program 131 " performs an operation of extracting only the pupil by removing the remaining connected components excluding the number of connections having the maximum number of pixels.

FIG. 7C is a binary image of a pupil obtained as a result of performing the steps of (a1) to (a5) in the "iris recognition program".

(Pupil center coordinate extraction step (S404e))

Next, the "iris recognition program 131" of the mobile terminal 1 performs an operation of extracting the center coordinates of the pupil using the binary image of the pupil obtained in the pupil image extraction step S404d.

7D, the iris recognition program 131 sets the center of the pupil to CP (alpha, beta), sets two points of the boundary point meeting with the straight line as P1 and P2, and P1 and P2 Is set to P3, and the boundary point of the circle where the waterline is intersected at P3 is set to P4. The iris recognition program 131 is an operation for calculating the distance from P3 to P4 by a, the half of P1 and P2 length by b, the radius by r, and calculating the radius by the following equation (2) . The iris recognition program 131 sets a value obtained by adding the radius r obtained by the following equation (2) to the y coordinate value in the coordinates of P4 as the value in the center coordinates CP (?,?), The value in CP (?,?) Is set to be equal to the x-coordinate value in the coordinates of P4.

(2)

(2)

7E is a diagram showing the center of the pupil extracted according to the pupil center coordinate extraction step (S404e). In this figure, the center of the pupil is indicated by a cross.

(Individual iris code generation step)

Next, the iris recognition program 131 determines the position of the iris by using the pupil center coordinates obtained through the pupil center coordinate extraction step S404e, analyzes the pattern of the iris image into a predetermined area, As shown in FIG.

The iris recognition program 131 applied to the mobile terminal 1 according to the present invention may be stored in advance in the mobile terminal 1 or may be stored in the memory 130 through downloading through a network .

Further, the iris recognition program 131 applied to the mobile terminal 1 according to the present invention may be recorded in a computer-readable recording medium. Examples of such a computer readable recording medium include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, and also implemented in the form of a carrier wave (e.g., transmission over the Internet) . The computer-readable recording medium may also be distributed over a networked computer system so that computer readable code in a distributed manner may be stored and executed. In addition, functional programs, codes, and code segments for implementing the present embodiment can be easily inferred by programmers in the technical field to which the present embodiment belongs.

Referring again to FIG. 2, the communication unit 160 performs voice communication processing and data communication processing with other terminals.

The control unit 170 controls the overall operation of the mobile terminal 1, for example, the iris imaging operation through the camera module unit 150, the authentication processing operation using the iris image photographed through the camera module unit 150, Performs operations to control each of the functional units 110 to 160 so that voice communication or data communication with other terminals, and functional operations according to various modes can be smoothly driven.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (6)

A mobile terminal supporting an iris recognition function,
A battery unit 110 for supplying power to the mobile terminal;
A memory unit 130 for storing an iris recognition program implementing the iris recognition function;
A touch screen unit 140 for sensing a touch command of the user regarding the iris recognition function and displaying a processing result of the touch command;
A camera module unit (150) configured to acquire an image of a subject including an iris;
A communication unit 160 for performing a communication function with another terminal through a mobile communication network;
And a controller (170) for driving the iris recognition program in response to detecting a touch instruction of a user regarding the iris recognition function,
The camera module unit 150,
A lens unit 151 for collecting reflected light from a subject including the iris,
A wavelength separating mirror part 152 capable of separating the light collected through the lens part 151 into light having a high wavelength and light having a low wavelength,
An iris recognition filter unit 153a for transmitting only light having a wavelength of 800 nanometers or more among the high wavelength light transmitted from the wavelength separation mirror unit 152,
A general image filter unit 153b that transmits only light having a wavelength of 650 nanometers or less in the light of the low wavelength transmitted from the wavelength separating mirror unit 152,
An image sensor unit 154 for outputting a digital signal relating to an iris image or a digital image relating to a general image by photoelectrically converting light having passed through the iris recognition filter unit 153a or the general image filter unit 153b Including,
Further comprising an infrared LED (180) capable of irradiating an object including the iris with infrared light having a wavelength of 800-900 nm,
The wavelength separating mirror portion 152 further includes a dichroic mirror,
The iris recognition program of the controller 170 may be configured to: (a) determine whether the current state of the mobile terminal is an iris capture mode or a general image capture mode; (b) driving the infrared LED (180) when the current state is the iris photographing mode; (c) causing the image sensor unit 154 to photoelectrically convert only the light acquired by the iris recognition filter unit 153a; (d) instructing the automatic iris image to automatically track the pupil position;
(D1) analyzing a histogram of an image of an iris among images captured through the image sensor unit 154; (d2) converting the image of the iris into a binarized binary image based on a threshold value obtained by analyzing the histogram; (d3) extracting only the binary image of the pupil by removing noise from the transformed binary image; (d4) extracting the center coordinates of the pupil using a binary image of the pupil; (d5) instructing to generate an iris code unique to a person by analyzing a pattern of an image of the iris based on the center coordinates of the pupil by predetermined regions. delete delete The method according to claim 1,
The wavelength separating mirror 152 is a dichroic mirror that transmits light having a wavelength of 700 nanometers or more as light of the high wavelength and reflects light having a wavelength of less than 700 nanometers as light of the low wavelength And a camera module capable of recognizing the iris.
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