KR20190089633A - Apparatus for determinating iris - Google Patents

Abstract

The present invention relates to an apparatus for recognizing an iris, which comprises: a storage unit storing final eye image data and position information of final pupil pixels included in a final pupil area, and pixel values; and an iris extraction unit generating a plurality of iris estimation areas by dividing the final eye image data by an iris estimation unit area along a predetermined row direction based on one outermost pixel column of the final pupil area, calculating average pixel values of the final eye image data corresponding to each iris estimation area, and using a difference value of the average pixel values of each iris estimation area of a plurality of iris estimation areas and a following iris estimation area spaced apart from each iris estimation area by a predetermined sequence to estimate the iris area.

Description

[0001] APPARATUS FOR DETERMINATING IRIS [0002]

The present invention relates to an iris recognition apparatus.

As a personal identification method for identifying each person, a password authentication method and an identification number authentication method are known, but these methods are likely to be exposed to theft and the risk of loss.

Therefore, in recent years, there has been a demand for a safer and more accurate personal identification method. A biometric identification method using biometric information of a person has been developed and used according to the demand.

Biometric information used for this biometric method is fingerprint, face, and iris in general.

The iris authentication method using the double iris is known to be the best in terms of uniqueness, invariance, and stability among individual identification methods, and is being applied to fields requiring high security.

The iris authentication is performed through a process of extracting the iris image of the subject and comparing the iris image already registered with the extracted iris image.

Korea Patent No. 10-0397750 (Registered Date: Aug. 29, 2003, entitled "Real-time Pupil Detection Method for Iris Recognition) Korean Patent No. 10-0572410 (Registered Date: April 12, 2006, entitled "Pupil Area Estimation Method for Iris Recognition)

A problem to be solved by the present invention is to accurately extract an iris region from an eye image of a photographee.

According to an aspect of the present invention, there is provided an iris recognition apparatus including a storage unit storing final eye image data, position information of a final pupil pixel included in a final pupil region and pixel values, A plurality of iris estimation regions are generated by dividing the final eye image data by a unit region for iris estimation along a predetermined row direction with reference to one row of the outermost pixel columns, and an average pixel value of the final eye image data corresponding to each iris estimation region And an iris extracting unit for estimating an iris region using difference values of average pixel values of the subsequent iris estimation regions spaced apart from the respective iris estimation regions by a predetermined sequence number among the plurality of iris estimation regions, .

The width of the iris estimation unit area and the size of the longitudinal side may be determined according to the radius of the final pupil area.

The iris extracting unit determines a difference value having the greatest absolute value among the calculated difference values, and determines the order of the corresponding iris estimation region indicating the determined difference value, and determines the row of the outermost pixel column of the iris estimation region And determine a circular area having a radius from the row position of the center pixel of the final pupil area to the row position of the row of the outermost pixel column as the iris area.

Wherein the iris extracting section determines a pixel column dividing reference pixel column spaced by a predetermined distance from a first outermost pixel column of the final pupil region by a predetermined distance in a predetermined row direction, It is possible to generate a plurality of iris estimation regions by dividing the eye image data.

Wherein the iris extracting unit extracts a pixel having a pixel value equal to or greater than a first set value and a pixel having a pixel value equal to or less than a second set value greater than the first set value in the final eye image data stored in the storage unit, A first preliminary pupil pixel is selected using a pixel having the same pixel value as the set value to determine a primary preliminary pupil region including the primary preliminary pupil pixel, The first preliminary pupil region is extended in the first and second column directions and in the first and second row directions by using the first to fourth reference pixels respectively located in the side pixel rows, the leftmost pixel column and the rightmost pixel column, And a second preliminary pupil region determined by the first and second rows and the first and second rows to determine a center pixel positioned at the center of the secondary preliminary pupil region, remind Determining a second preliminary pupil region included in the original region by determining a circular region having a distance to one of the first row, the second row, the first row and the second row as a radius, The region included can be determined as the final pupil region.

Wherein the iris extracting unit comprises: a first preliminary pupil pixel located in the middle of the uppermost pixel row in the primary preliminary pupil region; a primary preliminary pupil pixel located in the middle of the lowest pixel row; And the primary preliminary pupil pixel located at the center of the next preliminary pupil pixel and the rightmost pixel column may be defined as the first to fourth reference pixels, respectively.

Wherein the iris extracting unit sequentially shifts the position of the first comparison pixel in the column direction along the first column direction from the first reference pixel while the difference between the pixel value of the first reference pixel and the pixel value of the first comparison pixel is Determining a first comparison pixel that exceeds a set value and determining a column position of a first comparison pixel immediately before the determined first comparison pixel as a position of the first column, In which the difference between the pixel value of the second reference pixel and the pixel value of the second comparison pixel exceeds a set value while sequentially moving the position of the second comparison pixel in a column unit along the second column direction, The second comparison pixel is determined to be a second column, and the third reference pixel is determined to be the second comparison pixel in the row direction along the first row direction, 3 rain A third comparison pixel in which the difference between the pixel value of the third reference pixel and the pixel value of the third comparison pixel exceeds a set value while sequentially moving the position of the pixel, The position of the third comparison pixel is determined to be the position of the third reference pixel, and the position of the third comparison pixel is determined to be the position of the third comparison pixel in the second reference direction A fourth comparison pixel in which the difference between the pixel value of the fourth reference pixel and the pixel value of the fourth comparison pixel exceeds the set value while moving the fourth comparison pixel, The position can be determined as the position of the second row.

Wherein the iris extracting unit extracts a pixel having a pixel value equal to or greater than the first set value and a pixel having a pixel value equal to or less than a second set value greater than the first set value in the final eye image data as an estimated pupil pixel, It is possible to extract the first-order preliminary pupil pixels by removing the estimated pupil pixels that are not consecutively positioned by a predetermined number in any one of the row direction and the column direction and neighboring other estimated pupil pixels in the pixel.

The neighboring different estimated pupil pixels may be located consecutively with the estimated pupil pixels different in the row direction and the column direction.

The iris extracting unit may set the distance to the farthest of the first column, the second column, the first row, and the second row of the center pixel and the secondary preliminary pupil region as the radius of the circular region have.

The iris extracting unit may set the distance to the shortest one of the first column, the second column, the first row and the second row of the center pixel and the secondary preliminary pupil region as the radius of the circular region have.

According to this aspect, since the edge of the iris region is calculated by dividing the region outside the final pupil region by the unit region for iris estimation and using the difference of the average pixel values, the boundary portion of the accurate iris region is determined.

Also, the iris estimation region is divided from the region spaced by a predetermined distance from the edge portion of the final pupil region, and iris estimation for the final eye image data for the region located adjacent to the edge portion of the final pupil region, The dividing operation into the area and the operation of calculating the difference value of the average pixel value are omitted. As a result, the processing operation for determining the iris region is greatly shortened.

In addition, since the iris estimation region is divided according to a predetermined row space, instead of using the upper region or the lower region of the eye covered with the eyelid and the estimation operation of the iris region is not performed, The iris region is extracted using the final eye image data corresponding to the region, so that an accurate iris extraction operation is performed.

According to this aspect, since the primary preliminary pupil pixels for determining the final pupil region are extracted by the comparison operation between the pixel value and the set value in the final eye image data, Is greatly reduced. Thus, the data processing time is shortened and the extraction time of the final pupil area is reduced.

In addition, when extracting the secondary preliminary pupil region using the primary preliminary pupil region, the secondary preliminary pupil region is extracted through the pixel value comparison operation between the predetermined reference pixel and each of the comparison pixels positioned adjacent to the reference pixel. do. This improves the accuracy of the determination operation of the two-window preliminary pupil region for determining the final pupil region, thereby increasing the accuracy of the final pupil region.

1 is a block diagram of an iris recognition apparatus according to an embodiment of the present invention.
FIGS. 2A to 2D are operation flowcharts of an iris extracting unit for extracting a final pupil region in the iris recognition apparatus according to an embodiment of the present invention.
FIGS. 3A and 3B are diagrams for explaining a process of determining an estimated pupil region and a primary preliminary pupil region using final eye image data according to an operation of a pupil extracting unit of an iris recognition apparatus according to an embodiment of the present invention FIG. 3A is a diagram for explaining a process of determining an estimated pupil region, and FIG. 3B is a diagram for explaining a process of determining a primary estimated preliminary pupil region.
4 (a) and 4 (b) are views showing images of the primary preliminary pupil region determined by the pupil extracting unit of the iris recognition apparatus according to the embodiment of the present invention, wherein (a) (B) is a view showing an image obtained by extracting a primary preliminary pupil region from an eye image of (a) to an information output unit.
FIG. 5 is a diagram showing first to fourth reference pixels in a primary preliminary pupil region according to an operation of a pupil extracting unit of an iris recognition apparatus according to an embodiment of the present invention. FIG.
6 is a diagram for explaining a process of determining a secondary preliminary pupil region in a secondary preliminary pupil region according to an operation of a pupil extracting unit of an iris recognition apparatus according to an embodiment of the present invention.
FIG. 7 is a diagram showing an image of a secondary preliminary pupil region determined using the eye image shown in FIG. 4 (b). FIG.
8A and 8B are operation flowcharts of the iris extracting unit of the iris extracting unit in the iris recognition apparatus according to an embodiment of the present invention.
9 is a diagram for explaining a process for extracting an iris region in the iris recognition apparatus according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, if it is judged that it is possible to make the gist of the present invention obscure by adding a detailed description of a technique or configuration already known in the field, it is omitted from the detailed description. In addition, terms used in the present specification are terms used to appropriately express the embodiments of the present invention, which may vary depending on the person or custom in the relevant field. Therefore, the definitions of these terms should be based on the contents throughout this specification.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. As used herein, the meaning of "comprising" embodies certain features, areas, integers, steps, operations, elements and / or components, And the like.

Hereinafter, an iris recognition apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.

First, an iris recognition apparatus according to an embodiment of the present invention will be described with reference to FIG.

1, the iris recognition apparatus of the present embodiment includes an image acquisition unit 100, an iris extraction unit 200 connected to the image acquisition unit 100, a storage unit 200 connected to the pupil extraction unit 200, 300, and an information output unit 400 connected to the pupil extracting unit 200.

The image capturing unit 100 captures an image of a person to be photographed. The image capturing unit 100 of the present example captures an area including eyes from the face of the person to be imaged for iris recognition, (Hereinafter, this image data is referred to as 'original image data').

At this time, the image data of this example including the original image data has positional information and pixel values for a plurality of pixels arranged in a matrix structure, and the value of the image data for each pixel is a pixel value. Therefore, the image data is a set of pixels made up of a plurality of pixels having the corresponding pixel values.

At this time, the image capturing unit 100 may include an infrared camera for generating image data by infrared ray photographing in order to prevent red eye phenomenon of the subject during the photographing operation and accurately photograph the eye.

The iris extracting unit 200 receives the original image data from the image capturing unit 100 and extracts the iris region. The iris extracting unit 200 includes an eye image data extracting unit 210, a preprocessing unit 210 connected to the eye image data extracting unit 210, A pupil extraction unit 230 connected to the preprocessing unit 220, and an iris extraction unit 240 connected to the pupil extraction unit 230.

The eye image data extraction unit 210 extracts image data of the eye and eye region (hereinafter, this region is referred to as the eye region) from the eye part image data applied from the image pickup section 100 Image data "). The eye-image-data extracting unit 210 extracts eye-image data from original image data through an algorithm such as OpenCV which is already disclosed.

The preprocessing unit 220 generates a final eye image data by performing a conversion operation of the eye image data before extracting the pupil region. The preprocessing unit 220 performs various processes such as grayscale conversion processing, pixel number conversion processing, smoothing processing, and binarization processing At least one of the preprocessing operations for the plurality of image data is performed to convert the amount of the eye image data, the size of the pixel value, and the like so that the processing time for extracting the iris region can be shortened.

The preprocessing operation for the eye image data also uses a known processing operation, so a detailed description thereof will be omitted.

In an alternative example, the preprocessing operation of the present example for the original image data may be omitted, and in this case, the preprocessing unit 220 of this example is also omitted.

The pupil extracting unit 230 extracts image data for a pupil from the final eye image data applied from the preprocessing unit 220 to determine a pupil area.

The pupil extracting unit 230 firstly determines the primary preliminary pupil region using the pixel values of the final eye image data, and determines the pupil region of the first pupil region based on the uppermost pixel row, the lowest pixel row, And the first to fourth reference pixels located in the rightmost pixel column are used to sequentially change the positions of the first to fourth comparison pixels in which the pixel values are compared with the first to fourth reference pixels, The secondary pupil region in which the pupil region is extended in the first and second row directions and in the first and second row directions is determined.

Then, the pupil extracting unit 230 extracts the pupil extracting unit 230 from the center pixel located at the center of the secondary preliminary pupil region, the first column which is the column position of the uppermost pixel row of the secondary preliminary pupil region, A circular area having a radius up to one of the first row and the second row which is the row position of the first row and the leftmost row of pixels in the leftmost pixel column is determined and the secondary spare pupil area included in the original area is defined as The final pupil pixel is determined and the final pupil region is determined.

The iris extracting unit 240 extracts the iris region from the final eye image data of the eye region on the basis of the extracted pupil region.

To this end, the iris extracting unit 240 of this embodiment divides the final eye image data corresponding to the eye region at a position outside the final pupil region into iris estimation unit regions to generate a predetermined number of iris estimation regions, And the average pixel value difference between the iris estimation region and the adjacent iris estimation region adjacent to the iris estimation region at a predetermined interval to extract image data corresponding to the iris region from the final eye image data.

The storage unit 300 connected to the iris extracting unit 200 is a storage medium for storing data or information necessary for the operation of the iris recognition apparatus and image data generated during operation, and may be a memory or the like.

The storage unit 300 may include at least one of a temporary storage device such as a buffer and a permanent storage device such as a hard disk.

The information output unit 400 outputs the corresponding image by the operation of the iris extracting unit 200 so that the user can visually confirm the iris extraction process.

The information output unit 400 may be a liquid crystal display (LCD), an organic light emitting display (OLED), or the like.

Next, referring to Figs. 2A to 9, the operation of the iris recognition apparatus having such a structure will be described.

When power required for operation of the iris recognition apparatus is supplied and operation of the iris recognition apparatus is started, an operation of the image acquisition unit 100 performs an imaging operation on a face portion including an eye to acquire original image data.

In this case, when the image capturing unit 110 performs a photographing operation on a corresponding area (e.g., a face area) in conjunction with the operation of a driving switch (not shown) by a user or a person is detected in a designated area, A person's face can be photographed.

When the original image data is acquired and applied to the iris extracting unit 200 by the operation of the image acquiring unit 110 in step S11, the eye image data extracting unit 210 of the iris extracting unit 200 extracts, Extracts image data for the eye region from the image data, stores the extracted image data in the storage unit 300 as eye image data, and outputs the extracted eye image data to the preprocessing unit 220.

The preprocessing unit 220 performs at least one preprocessing operation such as gray-scale conversion processing, pixel number conversion processing, or smoothing processing on input eye image data, stores it in the storage unit 300, and preprocesses the eye image (Hereinafter referred to as "final eye image data") to the pupil extraction unit 230 (S13). In an alternative example, when the preprocessing unit 220 is not provided, the eye image data extracted by the eye image data extraction unit 210 becomes final eye image data.

Therefore, the pupil extracting unit 230 determines the pupil area using the transmitted final eye image data.

To this end, first, the pupil extracting unit 230 removes a pixel having a pixel value less than a first set value (lower limit value) and a pixel having a pixel value exceeding a second set value (upper limit value) in the final eye image data , Only pixels having a pixel value in a setting range that is equal to or greater than the first pixel value and equal to or less than the second pixel value in the final eye image data are extracted (S14).

In this case, the first set value is larger than the second set value, and the first set value is determined using the pixel value of the pixel belonging to the pupil region or the average pixel value, and the second set value is set based on the first set value .

By the extraction operation of such a pixel, the image data for an area (for example, the eye area) not primarily included in the iris area is removed.

Next, the pupil extracting unit 230 extracts only the pixels having the first set value which is the lower limit value of the set range among the extracted pixels (hereinafter, the extracted pixels are referred to as 'estimated pupil pixels') And stores the position information and the pixel value in the storage unit 300 (S15).

In this example, since the first set value is determined by using the pixel value of the pixel located in the region corresponding to the pupil, the estimated pupil pixel, which is the pixel having the first set value among the pixels belonging to the set range, And is included in the estimated pupil area AR11, which is an area that can be estimated as a region.

3A, the pupil extracting unit 230 includes an estimated pupil pixel PX11 existing in the uppermost row (e.g., a best-located pupil pixel) PX11, an estimated pupil pixel located in the lowermost column (For example, the lowest estimated pupil pixel) (PX12, PX13), the estimated pupil pixel (for example, the leftmost estimated pupil pixel) PX14 existing in the leftmost row and the estimated pupil pixel located at the rightmost row estimating the right-most pixel pupil) (PX15) a row and four-position information by the column position information _{(X n -9, X n,} Y p, Y p + 10) to _{[(X n -9, Y p} ) ( _E.g. , first to fourth edge pixels) [PX (X _n , Y _{p +10} )] each having the pixel values (X _{n -9} , Y _{p +10} ), (X _n , Y _p ) _{(X n -9, Y p)} , PX (X n -9, Y p +10), PX (X n, Y p) and _{PX (X n, Y p +10} )] for a rectangular area as the vertices As the estimated pupil area AR11 (S16).

Then, the pupil extracting unit 230 extracts the estimated pupil pixels that are not positioned consecutively in a predetermined number of directions in either one of the row direction and the column direction with other immediately adjacent estimated pupil pixels by using the position information of the estimated pupil pixel To extract the first-order preliminary pore pixels (S17).

At this time, neighboring other estimated pupil pixels are also located consecutively with other estimated pupil pixels immediately adjacent in the row and column directions.

For example, when the estimated pupil pixels belonging to the estimated pupil area AR11 are extracted as shown in FIG. 3A, the estimated pupil pixels PX14 to PX16 are excluded from the primary spare pore pixels.

That is, the estimated pupil pixel PX14 does not include other estimated pupil pixels immediately adjacent to the row direction and the column direction on the basis of the estimated pupil pixel PX14, and the estimated pupil pixel PX15 is also referred to as a reference pixel in the row direction and the column direction And does not have other estimated pupil pixels immediately adjacent thereto.

Therefore, these estimated pupil pixels PX14 and PX15 are not selected as primary preliminary estimation pixels.

The estimated pupil pixels PX16 and PX17 are located in the same pixel column (i.e., the column in which the positions of the rows are the same but the positions of the pixels are different), and are assumed to be the estimated pupil pixels that are consecutively arranged in the column direction. And other estimated pupil pixels that are continuously located in the column direction.

Therefore, these estimated pupil pixels PX16 and PX17 are also not selected as the primary spare pore pixels.

However, the estimated pupil pixels PX11-PX13 include other estimated pupil pixels positioned adjacent to the other estimated pupil pixels in the row direction. At this time, other estimated pupil pixels positioned adjacent to each other are also consecutively arranged in the row direction and the column direction And is in contact with another estimated pupil pixel. Therefore, these estimated pupil pixels PX11 to PX13 are selected as the primary spare pore pixels.

By the operation of the pupil extracting unit 230, the primary spare pore pixel is selected from the estimated pupil pixels located in the estimated pupil region AR11. An example of a primary spare pore pixel selected based on the estimated pupil pixel shown in Fig. 3A is shown in Fig. 3B.

3B, when the first-order preliminary pore pixels are selected from among the estimated pore pixels included in the estimated pupil area AR11, the pupil extraction unit 230 uses the position information of the first-order preliminary pore pixels The region including the primary pore pixels is defined as the primary preliminary pupil region AR12 (S18).

At this time, as in the case of the estimated pupil region AR11, the primary preliminary pupil region AR12 is divided into a pixel existing in the uppermost row (i.e., the uppermost row) (X _{n -9} , X _n ) and column position information (Y _p (X _n )) of the pixel located at the leftmost (leftmost) , Y _{p + 10)} four-position information [(X _{n -9,} Y _p by _{a), (X n -9, Y} p +10), (X n, Y p) and a (X _n, Y _{p + 10)} the four pixels each having _{[PX (X n -9, Y} p), PX (X n -9, Y p +10), PX (X n, Y p) and PX (X _n, Y _{p +10} )].

As described above, by the operation of the pupil extracting unit 230, the primary spare pore pixels selected from the estimated pupil pixels belonging to the estimated pupil area AR11 shown in FIG. 3A are as shown in FIG. 3B, A preliminary pupil region AR12 is formed.

An example of the eye image for the primary spare pupil area AR12 extracted from the final eye image data output through the information output unit 400 by the operation of the pupil extracting unit 230 is shown in FIG. ). 4A shows an eye image output to the information output unit 400 according to the final eye image data. FIG. 4B shows a first preliminary pupil region AR12 in the eye image of FIG. And the information output unit 400 displays the extracted image.

Thus, when the primary spare pore pixels and the primary spare pupil area AR12 to which they belong are determined, the pupil extracting unit 230 performs an operation of determining the secondary spare pupil area AR13.

Therefore, the pupil extracting unit 230 first determines the first to fourth reference pixels PXr1, PXr2, PXr3, and PXr4, and stores position information on the determined reference pixels PXr1, PXr2, PXr3, PXr4, (Step S19).

5, the pupil extracting unit 230 extracts, from the primary spare pupil region AR12, a primary preliminary pupil pixel positioned at the center of the pixel row located in the uppermost row Y _p , Primary preliminary pupil pixels positioned at the center of the pixel row located in the row (Y _{p + 10} ), primary preliminary pupil pixels positioned at the center of the pixel column located at the leftmost row (X _{n - 7} ) X _{n - 1} are defined as the first to fourth reference pixels PXr 1 to PXr 4, respectively.

Thus, the pupil extracting unit 230 is the first of four primary pre pupil pixel located at each corner portion of the pupillary spare area (AR12) [PX _{(n -9} X, Y _p), PX (X _{n -9, Y p +10), PX (X} n, Y p) and _{PX (X n, Y p +10} )] position information _{(X n -9, X n,} Y p, Y p + 10) using a first of the The primary preliminary pupil pixels positioned at the center in the uppermost pixel row, the lowermost pixel row, the leftmost pixel column, and the rightmost pixel column of the next preliminary pupil region AR12 are referred to as first through fourth reference pixels PXr1, PXr2, PXr3, and PXr4, and stores the position information on the first to fourth reference pixels PXr1, PXr2, PXr3, and PXr4 in the storage unit 300. [

At this time, the pupil extracting unit 230 does not have a primary preliminary pupil pixel located at the center in the uppermost pixel row, the lowest pixel row, the leftmost pixel column, and the rightmost pixel column of the primary spare pupil region AR12 , One primary spare pore pixel located closest to the pixel position in the middle of the pixel row or pixel column is determined as the reference pixel (e.g., PXr3).

As such, each edge pixel in each of the primary spare pupil area _{(AR12) [PX (X n} -9, Y p), PX (X n-9, Y p +10), PX (X n, Y p) and PX (X _n, Y _{p +10)]} using the location information of a primary spare pupil area (AR12) first to fourth standard number of pixels (PXr1, PXr2, PXr3, PXr4) is determined when the pupil extraction unit in the ( 230 form a primary preliminary pupil region AR12 extending in the first and second column directions and in the first and second row directions using the reference pixels PXr1, PXr2, PXr3, PXr4, The area AR13 is determined.

Therefore, the pupil extracting unit 230 extracts the pupil extracting unit 230 from the final eye image data stored in the storage unit 300, which is located immediately above the first reference pixel PXr1 located at the uppermost pixel row of the primary spare pupil region AR12 (I.e., the Y direction in which the number of the column is decreased) in one column unit in the first preliminary pupil pixel, that is, in the same row (X _{n - 3} ) and is located immediately above the first reference pixel PXr 1 The first preliminary pupil pixel is determined as the first comparison pixel PXc1 (S110).

6, the first comparison pixel (i.e., the current first comparison pixel) PXc1 is set to a position where the number of the column is decreased by '1' in the same pixel column as the first reference pixel PXr1 (PXr1 _{- 1} ) located at Y _{p - 1} .

Next, by comparing the determined pixel value of the current first comparison pixel PXc1 with the pixel value of the first reference pixel PXr1 and comparing the first reference pixel PXr1 with the current first comparison pixel PXc1 It is determined whether the difference between the pixel values is equal to or less than the set value (S111, S112).

If the difference between the pixel values of the first reference pixel PXr1 and the current first comparison pixel PXc1 is equal to or smaller than the set value (S112), the pupil extracting unit 230 returns to the first comparison pixel moved by one row, and the first preliminary pupil pixel (PXr1 _{- 2)} which is located immediately above in the same pixel column and the present first comparison pixel establish a new current first comparison pixel (PXc1) (S113), first It is determined whether the difference between the pixel values of the reference pixel pixel PXr1 and the current first comparison pixel PXc1 is equal to or less than the set value at step S111. At this time, it is natural that the comparison pixels immediately before the new first comparison pixels are stored as the previous comparison pixels and the newly determined first comparison pixels are stored as the current comparison pixels.

However, if the difference between the pixel values of the first reference pixel PXr1 and the current first comparison pixel PXc1 exceeds the set value (S112), the pupil extracting unit 230 determines that the previous first comparison pixel PXc1 (For example, the first row position) of the second preliminary pupil area AR13, and stores the position of the row in the storage unit 300. [

Therefore, the pupil extracting unit 230 extracts the first preliminary papillon pixels (e.g., PXr1 _- PXr1) determined as the previous first comparison pixel PXc1 immediately before the pixel value difference with the first reference pixel PXr1 has a set value or less, using ₃₎ the primary spare pupil pixel (for example, PXr1 _{- - 3)} location information (X _{n -3,} Y _p of the determined ₃₎ to the first position in the column ₍₃₎ is located in a column position (Y _p S114).

As described above, the pupil extracting unit 230 sequentially moves the positions of the first comparison pixels PXc1 in a column unit along the first column direction in the first reference pixel PXr1, (I.e., the current first comparison pixel) whose pixel value difference from the first comparison pixel PXc1 exceeds the set value, and determines the first comparison pixel PXc1 The column position of the determined first comparison pixel (i.e., the previous first comparison pixel) is determined as the first column position.

Similarly to this method, the pupil extracting unit 230 again uses the second reference pixel PXr2 to determine the position of the lowermost row (e.g., the second row position) of the primary preliminary pupil area AR13.

That is, the pupil extracting unit 230 extracts the second reference pixel PXr2 located in the lowermost row (Y _{p + 10} ) of the first preliminary pupil region AR12 from the final eye image data stored in the storage unit 300, (PXr2 _{+ 1} ) located immediately below by one column unit in the second column direction (i.e., the Y direction in which the column number increases in the direction opposite to the first column direction) at the position of the first preliminary pupil pixel 2 comparison pixel PXc2, and determines whether the pixel value of the current second comparison pixel PXc2 exceeds the pixel value of the second reference pixel PXr2 (S115-S117).

The difference between the pixel values of the second comparative pixel PXc2 and the second reference pixel PXr2 is equal to or smaller than the set value (S117), and the first preliminary pupil pixel PXr2 _{+ 1} , which is the second comparative pixel, The first preliminary pupil pixel PXr2 _{+ 2} immediately below the second preliminary pupil PXr2 is set as a new current second comparison pixel PXc2 (S118), and pixel value comparison with the second reference pixel PXr2 is performed (S115).

Therefore, the pupil extracting unit 230 sequentially changes the current second comparison pixel PXc2 until the pixel value difference between the second comparison pixel PXc2 and the second reference pixel PXr2 exceeds the set value A pixel value comparison operation is performed.

If the difference between the pixel value of the second comparison pixel PXc2 and the pixel value of the current second reference pixel PXr2 exceeds the set value, the pupil extracting unit 230 outputs the second comparison immediately before the current second comparison pixel PXc2 (Y _{P + 11} ) of the primary preliminary pupil pixel (for example, PXr 2 ₊₁ ), which is a previous second comparison pixel determined as a pixel, as the second row position of the secondary pupil region AR 13 (S 119).

The pupil extracting unit 230 extracts the third and fourth reference pixels PXr3 and PXr4 from the third and fourth reference pixels PXr3 and PXr4, The current third comparative pixel PXc3 and the current fourth comparative pixel PXc4 are determined and the current pixel values of the third and fourth comparison pixels PXc3 and PXc4 and the third and fourth reference pixels PXr3, (E.g., the first row position) and the position of the rightmost row (e.g., the second row position) of the secondary pupil region are determined by comparing the pixel values of the left pupil region and the right pupil region.

At this time, when the first and second column positions are determined, the positions of the secondary spare pore pixels are decreased or increased from one of the corresponding reference pixels PXr1 and PXr2 in one column unit along the first and second column directions, The first and second comparison pixels PXc1 and PXc2 are determined. However, when the first and second row positions are determined, the first and second comparison pixels PXc3 and PXc4 are arranged in a row unit from the corresponding reference pixels PXr3 and PXr4 along the first and second row directions. Only the third and fourth comparative pixels PXc3 and PXc4 are determined (S120-S124, S125-S129) by decreasing or increasing the position of the secondary spare pore pixel.

Here, the first row direction is the X direction in which the number of the rows is decreasing, and the second row direction is the X direction in which the number of the row increases in the direction opposite to the first row direction.

With such a pixel value comparison operation of the pupil extracting unit 230, a current third comparison pixel primary spare pupil pixel determined as (PXc3) (PXr3 _{- 3)} and the primary spare pupil defined as of the fourth comparison pixel (PXc4) pixel (PXr4 _{+ 4)} If the pixel value difference between the first pre-pupil pixels in excess of the set value, respectively, located in the same column, and these pre-primary pupil pixel (PXr3 _-3, PXr4 _{+ 4)} present immediately before between the third comparing a pixel (PXc3) and the fourth pixel comparing a first row position of the primary spare pupil pixel (PXr3 _-2, PXr4 _{+ 3)} a secondary spare pupil area (AR13) of each line position which was determined by (PXc4) and the 2 row position.

When the first and second row positions and the first and second row positions are determined by the operation of the pupil extracting unit 230, the pupil extracting unit 230 extracts a region partitioned by a quadrangle And a pixel included in the secondary spare pupil region AR13 is stored in the storage unit 300 as a secondary spare pore pixel (S130).

An example of the secondary spare pupil area AR13 extracted from the primary spare pupil area AR12 shown in FIG. 3B by the operation of the pupil extracting unit 230 is shown in FIG.

As described above, the secondary preliminary pupil region AR13 is determined on the basis of the primary preliminary pupil region AR12, but the degree of expansion in the column direction and in the row direction is different between the reference pixels PXr1-PXr4 and the respective comparison pixels PXc1-PXc4), the position of the primary preliminary pupil pixel located at the center of the primary preliminary pupil region AR12 and the position of the secondary preliminary pupil pixel located at the center of the secondary preliminary pupil region AR13 The positions of the preliminary pore pixels may be different from each other.

Therefore, the accuracy of the extraction operation of the final pupil region is increased by the operation of the pupil extraction unit 230 according to the present example.

By the operation of the pupil extraction unit 230, the secondary spare pupil area AR13 extracted based on the image shown in FIG. 4B can be output to the information output unit 400 as shown in FIG. have.

Thus, when the second preliminary pupil area (AR13) is extracted, the pupil extracting unit 230, each edge pixel located at the four corners of the secondary spare pupil area (AR13) [PX _{(n -9} X, Y _{p -3 ), PX (X n-9} , Y p +11, PX (X n +2, Y p +3), PX (X n +2, Y p +11)] position information (X _{n -9,} X of _the secondary preliminary pupil pixel located in the middle portion of the secondary preliminary pupil region AR13 is used as the center pixel PX of the secondary preliminary pupil region AR13 by using the pixel PX ( _{n + 2} , Y _{p -3} , Y _{P + 11} ) is determined by _cent) (S131).

Then, the pupil extracting unit 230 calculates the distance R131 from the center pixel PX _cent to the first and second columns using the positional information of the secondary spare pore pixel included in the secondary spare pupil area AR13 , R132) and the distances R133 and R134 to the first and second rows are calculated (S131). In this case, the distances R131, R132, R133 and R134 are the straight line distances from the first and second columns to the pixel located in the same column as the center pixel PX _cent in the first and second rows.

As described above, the uppermost row (first row), the lowermost row (second row), the leftmost row (first row), and the rightmost row (second row) of the secondary preliminary pupil region AR13 from the center pixel PX _cent The pupil extracting unit 230 calculates distances R131 and R132 having the greatest value among the calculated distances R131, R132, R133, and R134, as the distances R131, R132, R133, and R134 (S133).

Next, the pupil extracting unit 230 determines a circular region having a radius (e.g., R131) determined based on the center pixel PX _cent as a center point, and determines a secondary preliminary pupil pixel included in the circular region as a final pupil pixel And the region including these final pupil pixels is determined as the final pupil region AR20 (S134).

In this case, since the final pupil area AR20 is determined using the largest value among the calculated distances R131, R132, R133, and R134, it is possible to accurately extract the pupil area without any part excluded from the actual pupil area .

However, unlike the present example, in the alternative example, the final pupil area AR20 may be determined using the smallest value among the calculated distances R131, R132, R133, and R134. In this case, The accuracy of the final pupil pixel included in the image is increased.

Then, the position information and pixel values of the secondary spare pore pixels included in the final pupil area AR20 are stored in the storage unit 300 as position information and pixel values of the final pupil pixel (S135).

By the operation of the pupil extracting unit 230 of this example, the final pupil area AR20 extracted based on the image of Fig. 7 is shown in Fig.

When the final pupil region AR20 is determined, the pupil extracting unit 230 notifies the iris extracting unit 240 of the completion state of the pupil extracting operation, thereby starting the operation of the iris extracting unit 240 (S20) .

Thus, the iris extracting unit 240 extracts the iris image using the distance (e.g., R131) determined for the final pupil area AR20, i.e., the radius size R131 of the final pupil area AR20, The size is determined, and the size of the side of the road is determined based on the size of the determined longitudinal side (S21).

At this time, the unit area for iris estimation is a rectangular area, and the size of the longitudinal side is larger than the size of the transverse side, and the size ratio (R131) and the ratio of the size of the longitudinal side and the lateral side are already determined.

9, the iris extracting unit 240 extracts the pixel array located at the leftmost one of the one or more outermost pixel columns (i.e., the left pupil region AR20 of the determined final pupil region AR20) (I.e., a predetermined number of rows) R50, which is one of the first row direction and the second row direction (e.g., one of the pixel columns located in the first row direction) (Hereinafter, this pixel column is referred to as a 'division reference pixel column') (S22).

At this time, the predetermined distance R50 is already determined using the radius magnitude R131 of the final pupil area AR20.

Accordingly, the iris extracting unit 240 moves the final eye image data, that is, the final eye image data corresponding to the eye region, from the division reference pixel column to the first row direction or the second row direction among the final eye image data, (For example, m) iris estimation areas by dividing the iris estimation area by the unit area and calculating the difference value of the average pixel value by pairing the generated iris estimation areas with other iris estimation areas sequentially determined, And performs an operation of calculating an absolute value of the difference value.

Since the calculation of the average pixel value is performed for the eye region spaced by the predetermined distance R50, the final eye image data for the eye region which is certainly the iris region, that is, the final eye image data for the final pupil region The division operation to the iris estimation region and the difference value calculation operation of the average pixel value for the eye region located adjacent to the edge portion of the iris extraction unit AR20 are omitted and the processing time of the iris extraction unit 240 is shortened.

In addition, as the final eye image data division operation is performed while moving in the first or second row direction instead of the first or second column direction, the iris extraction unit 240 extracts, from the final eye image data, The iris region is extracted using the final eye image data corresponding to the left side region or the right side region of the eye instead of the final eye image data corresponding to the lower region. Therefore, the iris region is estimated using the left region of the eye or the right region of the eye photographed without being covered with the eyelid, so that the accurate iris region can be determined.

Accordingly, the iris extracting unit 240 extracts the final eye image data corresponding to the eye region moved by the iris-tracking unit region in the first direction from the division reference pixel column among the final eye image data, As the image data of the i-th iris estimation area DR1 (S23).

Then, the iris extracting unit 240 calculates and stores the average pixel value of the pixels for the image data belonging to the extracted i-th iris estimation region (S23, S24). Here, i = 1, 2, 3, ..., m.

At this time, the column position of the iris tracing unit area is determined so that the pixel positioned at the center of the pixel column in the i-th iris estimation area and the center pixel (PX _cent ) of the final pupil area AR20 are positioned in the same column.

The operation of the iris extracting unit 240 extracts image data corresponding to the first iris estimation area from the final eye image data corresponding to the eye image. Since the operation of the iris extracting unit 240 is performed until a predetermined number of iris estimation regions are generated, the final eye image data related to the eye region is eventually divided into a plurality of iris estimation regions. At this time, the total number of the iris estimation regions to be divided is already determined, and the total number can be varied according to the size of the radius R131 of the final pupil region.

Accordingly, the iris extracting unit 240 determines whether the number of total iris estimation regions generated so far has reached the set number (S25). If the iris estimation region is not generated by the set number, 1 '(i = i + 1), and the process proceeds to step S23 (S26).

Accordingly, the iris extracting unit 240 extracts the final eye image data corresponding to the eye region moved in the first row direction by the iris estimation unit region again in the current iris estimation region, In the storage unit 300 and calculates an average pixel value of the second iris estimation area DR2 and stores the calculated average pixel value in the storage unit 300. [

However, if the number of currently-generated iris estimation areas reaches the set number (m) and the number of iris estimation areas corresponding to the set number is generated in step S25, the iris extraction unit 240 extracts the iris estimation area I-th iris estimation region (e.g., the first iris estimation region) and the (i + j) -th iris estimation region (i + j), which are spaced apart from the iris estimation region by a predetermined number (E.g., the second iris estimation area). Where j can be, for example, 2 as a set value.

At this time, the value of the predetermined number (j) is determined according to the size of the side of the iris estimation unit area, decreases as the size of the side increases, and increases as the size of the side decreases.

Accordingly, the iris extracting unit 240 first calculates the difference value between the average pixel value of the first iris estimation area DR1 and the average pixel value of the third iris estimation area DR3, and stores the absolute value of the difference value And stores it in the unit 300 (S26).

Then, the iris extracting unit 240 extracts the average iris value of the second iris estimation area DR2, which is a new first iris estimation area in which the order of the first iris estimation area is increased by '1' Of the fourth iris estimation area DR4, which is a new second iris estimation area spaced by a predetermined number (i.e., two) from the first iris estimation area DR4, and stores the absolute value of the difference in the average pixel value, (S27, S28).

As described above, the iris extracting unit 240 increases the order of the generated iris estimation regions (m) in order and calculates an average pixel value difference between the iris estimation region and other iris estimation regions, The storage operation is repeatedly performed.

Accordingly, when the calculation of the difference value of the average pixel value for the iris estimation area up to the predetermined sequence number (i = mj) and the operation for storing the absolute value thereof are completed, the iris extraction unit 240 calculates the average pixel value of the generated iris estimation area And ends the absolute value storing operation.

Since the iris extracting unit 240 calculates the difference value between the two average pixel values until there are two iris estimation regions capable of calculating the difference value of the average pixel values, The difference value calculation and the absolute value storage operation for the average pixel value for the iris estimation region and the predetermined number (j = 2) including the iris estimation region of the last order (i = m) are not performed .

For example, if the number of generated iris estimation regions is 50, the first to 50th iris estimation regions exist, and the value of the predetermined separation distance is '2', then the first to 48th iris estimation regions A difference value calculation and an absolute value storage operation for the average pixel value are performed. However, since the 50 < th > iris estimation region and the 49 < th > iris estimation region do not exist in the last 50 iris estimation region and the 49 < th > iris estimation region, The difference value calculation and the absolute value storing operation for the average pixel value for the pixel value of the pixel value are not performed.

When the calculation of the difference value of the average pixel value for the iris estimation area up to the predetermined sequence number (i = mj) and the operation for storing the absolute value thereof are completed, the iris extraction unit 240 calculates the difference value The absolute value is determined (S29), and the order of the corresponding iris estimation area having the largest difference from the average pixel value of the adjacent iris estimation area adjacent to the adjacent iris estimation area is determined (S210).

Next, the iris estimation unit 240 determines the row position of the outermost pixel column by using the position information of the outermost pixel column located at the outermost one among the pixel columns belonging to the iris estimation area of the determined order (S211).

When the row position of the outermost pixel row is determined, the iris extracting unit 240 calculates the straight line distance from the row in which the center pixel PX _cent is located to the row of the outermost pixel row, and calculates the calculated distance as the iris region radius R30 ) (S212, S213).

Then, the iris extracting unit 240 determines an original area having the calculated iris area radius R30 as a radius and defines it as the iris area AR30 (S214) Information (i.e., pixel position and pixel value) is stored in the storage unit 300 as information of the iris pixels (S215).

In this example, the iris estimation region is generated while moving by the iris estimation unit region in the first direction, and the final eye image data for each generated iris estimation region is extracted from the final eye image data to estimate the iris region. And a second row direction that is the direction opposite to the first row direction by a unit of the iris estimation unit region, the plurality of iris estimation regions can be generated.

According to the operation of this embodiment, since the iris region is extracted from the final eye image data, even the iris region located at the boundary with the whiteness portion is accurately extracted into the iris region, thereby improving the accuracy of the iris extraction operation.

The embodiments of the iris extracting apparatus of the present invention have been described above. The present invention is not limited to the above-described embodiments and the accompanying drawings, and various modifications and changes may be made by those skilled in the art to which the present invention pertains. Accordingly, the scope of the present invention should be determined not only by the claims of the present specification, but also by equivalents to the claims.

100: image acquiring unit 200: iris extracting unit
210: eye image data extraction unit 220: preprocessing unit
230: pupil extraction unit 240: iris extraction unit
300:

Claims (11)

A storage unit for storing final eye image data, position information of the last pupil pixel included in the final pupil region, and pixel values; And
Dividing the final eye image data by a unit area for iris estimation along a predetermined row direction with reference to one outermost pixel column of the final pupil area to generate a plurality of iris estimation areas, Calculating an average pixel value of the iris region using the difference value between the average iris region and the average iris pixel value of the subsequent iris region that is spaced apart from the iris region by a predetermined sequence number, The iris-
And an iris recognition device. The method of claim 1,
Wherein the iris estimation unit region has a width and a length of a side of the iris region, the iris size being determined according to a radius of the final pupil region. The method of claim 1,
Wherein the iris extracting unit comprises:
Determining a difference value having the largest absolute value among the calculated difference values,
Determining the order of the corresponding iris estimation region indicating the determined difference value, determining the row position of the outermost pixel column of the determined iris estimation region,
A circular area having a radius from the row position of the center pixel of the final pupil area to the row position of the outermost pixel column is determined as the iris area
Iris recognition device. The method of claim 1,
Wherein the iris extracting unit comprises:
A pixel column dividing reference pixel column which is spaced apart from the one outermost pixel column of the final pupil region by a predetermined distance in a predetermined row direction is determined,
Dividing the final eye image data by the iris estimation unit area from the division reference pixel column to generate a plurality of iris estimation areas
Iris recognition device. The method of claim 1,
Wherein the iris extracting unit comprises:
Extracting a pixel having a pixel value equal to or greater than a first set value and a pixel having a pixel value equal to or less than a second set value greater than the first set value in the final eye image data stored in the storage unit, A first preliminary pupil pixel is selected using a pixel having a pixel value to determine a primary preliminary pupil region including the primary preliminary pupil pixel,
The first to fourth reference pixels located respectively in the uppermost pixel row, the lowermost pixel row, the leftmost pixel column, and the rightmost pixel column of the primary preliminary pupil region, A second preliminary pupil region determined by the first and second rows and the first and second rows is determined by extending the first row and the second row in the second row direction and the second row direction,
A circle having a radius as a distance from the center pixel positioned at the center of the secondary preliminary pupil region to one of the first column, the second column, the first row, and the second row of the secondary preliminary pupil region, The secondary pupil region included in the original region is determined as the final pupil pixel, and the region including the final pupil pixel is determined as the final pupil region
Iris recognition device. The method of claim 5,
Wherein the iris extracting unit comprises: a first preliminary pupil pixel located in the middle of the uppermost pixel row in the primary preliminary pupil region; a primary preliminary pupil pixel located in the middle of the lowest pixel row; And the primary preliminary pupil pixel positioned at the center of the next preliminary pupil pixel and the rightmost pixel column as the first to fourth reference pixels, respectively. The method of claim 5,
Wherein the iris extracting unit comprises:
The difference between the pixel value of the first reference pixel and the pixel value of the first comparison pixel exceeds the set value while sequentially moving the position of the first comparison pixel from the first reference pixel in the column direction along the first column direction, Determining a first column of the first comparison pixel immediately before the determined first comparison pixel as a position of the first column,
The second reference pixels are sequentially moved in the column direction along the second column direction opposite to the first column direction, and the pixel values of the second reference pixels and the second comparison pixels Determining a second comparison pixel whose difference in pixel value exceeds a set value and determining a column position of a second comparison pixel immediately before the determined second comparison pixel as a position of the second row,
Wherein the third reference pixel is arranged to sequentially move the position of the third comparison pixel in a row unit along the first row direction while the difference between the pixel value of the third reference pixel and the pixel value of the third comparison pixel exceeds the set value And determines the row position of the third comparison pixel immediately before the determined third comparison pixel as the position of the first row,
The fourth reference pixel and the fourth reference pixel are sequentially moved in the row direction along the second row direction opposite to the first row direction, The fourth comparative pixel whose difference in pixel value exceeds the set value is determined and the row position of the fourth comparative pixel immediately before the determined fourth comparative pixel is determined as the position of the second row
Iris recognition device. The method of claim 5,
Wherein the iris extracting unit comprises:
Extracting a pixel having a pixel value greater than or equal to the first set value and a pixel having a pixel value less than or equal to a second set value greater than the first set value in the final eye image data,
The estimated pupil pixels that are not located consecutively in a predetermined number of times in either one of the row direction and the column direction with respect to the neighboring other estimated pupil pixels among the estimated pupil pixels are removed to extract the primary preliminary pupil pixels
Iris recognition device. 9. The method of claim 8,
And the other neighboring estimated pupil pixels are located consecutively with the estimated pupil pixels different in the row direction and the column direction. 9. The method of claim 8,
Wherein the iris extracting unit extracts a distance between the center pixel and the second preliminary pupil region in the first column, the second column, the first row, and the second row, Recognition device. 9. The method of claim 8,
Wherein the iris extracting unit calculates the distance between the center pixel and the second row, the second row, the first row, and the second row of the secondary preliminary pupil region as the radius of the circular region, Recognition device.

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