TWI676937B - Fingerprint enrollment method and electronic device for the same - Google Patents

Abstract

The invention is a fingerprint registration method and an electronic device thereof. The method provides an instruction to prompt a user to move a finger in a spiral path on the fingerprint sensor for fingerprint registration. During the movement, the fingerprint sensor The finger is sensed to obtain multiple fingerprint images. The fingerprint registration method according to the present invention can effectively shorten the registration time, and it is easier to obtain a fingerprint image without deformation.

Description

Fingerprint registration method and electronic device

The present invention relates to the registration of biological characteristics, and more particularly to a method for registering fingerprints.

Fingerprint recognition is currently commonly used on electronic devices. As a user identification technology, users must register the fingerprint of at least one finger in the electronic device in advance. When identification is required (such as unlocking an electronic device, opening a specific application, using a specific function, etc.), the electronic device senses the user's fingerprint and compares it with a pre-registered fingerprint to identify the user's identity.

Generally, the size of a fingerprint sensor is smaller than a finger. A fingerprint registration method in the prior art requires a user to press the fingerprint sensor multiple times with different parts of the finger. Referring to FIG. 13, during multiple pressing processes, the fingerprint sensor obtains multiple fingerprint images 60 of the finger as fingerprint registration information. There are disadvantages to this approach. The user cannot actually confirm whether he has pressed each part of the finger over the fingerprint sensor, so the multiple fingerprint images 60 obtained by the fingerprint sensor are usually not complete, and the user is required to increase the number of pressings. This method is not convenient for users, and it will increase the registration time.

Another fingerprint registration method in the prior art is a swipe registration method. As shown in FIG. 14, the user must slide the finger on the fingerprint sensor in different directions multiple times to allow the fingerprint sensor to obtain fingerprint images 70 of different parts of the finger as fingerprint registration information. There are disadvantages to this approach. As shown in FIG. 15, the arrow in FIG. 15 represents the direction in which the finger slides on the fingerprint sensor. When the finger slides on the fingerprint sensor until it leaves the fingerprint sensor, the force with which the finger touches will change, and the movement speed of the finger will usually be faster and faster, making it easier for the fingerprint sensor to capture deformed fingerprints. The images are shown in, for example, fingerprint images 71 and 72.

In view of this, the present invention proposes a fingerprint registration method, in order to solve the shortcomings in the prior art that the registration time is too long, the obtained fingerprint image is not complete, and the deformed fingerprint image is easily captured.

In order to achieve the above-mentioned object of the invention, the technical means adopted by the present invention is to provide a fingerprint registration method, the method includes: (a) providing an instruction, the instruction is used to prompt the user to use a spiral path for a finger to sense a fingerprint And (b) when the finger moves on the fingerprint sensor, the fingerprint sensor senses the finger to obtain multiple fingerprint images.

In another aspect, the present invention provides an electronic device including: a fingerprint sensor; and a display that displays an instruction when the electronic device performs fingerprint registration; wherein the instruction is used to prompt a user The finger is moved on the fingerprint sensor in a spiral path, so that the fingerprint sensor obtains multiple fingerprint images.

The advantage of the present invention is that the user is reminded to perform fingerprint registration through a spiral path through instructions. The movement of the finger in a spiral shape allows the fingerprint sensor to collect multiple fingerprint images in a short time, which not only can effectively shorten the registration time, but also makes it difficult to obtain deformed fingerprint images.

Please refer to FIG. 12. According to an embodiment of the present invention, an electronic device includes a fingerprint sensor 20, a display 40, a processing unit 21, and a storage medium 22. The processing unit 21 is coupled to the fingerprint sensor 20 and the display 40. And storage medium 22. The fingerprint sensor 20 is used for sensing a fingerprint of a finger. The fingerprint sensor 20 is smaller in size than the finger. For example, the size of current fingerprint sensors is 6mm * 6mm to 12mm * 12mm, and the size of a finger is about 20mm * 20mm. The fingerprint sensor 20 may be an optical type or a capacitive type, and may be applicable to the present invention.

Please refer to FIG. 1A. The fingerprint registration method of the present invention includes the following steps:

Provide a registration path instruction (S10): The processing unit 21 provides an instruction, which is used to prompt the user to move a finger in a spiral path on a fingerprint sensor. In one embodiment, the indication is a visually visible indication. When the electronic device performs the fingerprint registration operation, the processing unit 21 provides the instruction to the display 40 and causes the display 40 to display the instruction. The display may have a variety of different implementations, but is not limited thereto. In other embodiments, the instruction may also be an audio instruction.

Obtaining a fingerprint image (S20): Please refer to FIG. 2 and FIG. 3. When the finger 10 is on the fingerprint sensor 20, the fingerprint sensor 20 senses the finger 10 to obtain a fingerprint image 30. Since the size of the fingerprint sensor 20 is smaller than that of the finger 10, the fingerprint image 30 is an image of a part of a complete fingerprint of the finger 10. During the movement of the finger 10 on the fingerprint sensor 20, the fingerprint sensor 20 performs multiple sensing on the finger 10 to obtain multiple fingerprint images 30.

The fingerprint sensor 20 transmits the obtained multiple fingerprint images 30 to the processing unit 21, and the processing unit 21 generates one or more fingerprint registration information based on the multiple fingerprint images 30.

In an embodiment, the method of the present invention further includes a plurality of steps S30 to S50 shown in FIG. 1B. The codes corresponding to steps S30, S40, and S50 are stored in the storage medium 22. The processing unit 21 implements steps S30, S40, and S50 by executing the code in the storage medium 22.

Step S30 is used to determine whether the fingerprint image 30 obtained in step S20 is qualified. When the fingerprint image 30 is determined to be qualified, step S40 is performed to generate fingerprint registration information according to the qualified fingerprint image 30. When the fingerprint image 30 is determined to be unqualified, step S50 is performed to discard the unqualified fingerprint image 30.

During the fingerprint registration process, steps S20 to S50 are repeated several times to obtain multiple qualified fingerprint images 30. In an embodiment, the processing unit 21 further accumulates the number of qualified fingerprint images 30. When the cumulative number of the qualified fingerprint images 30 reaches a preset value (for example, 20), the processing unit 21 notifies the fingerprint sensing The device 20 stops sensing the finger 10.

The processing unit 21 generates a plurality of fingerprint registration information based on the plurality of qualified fingerprint images 30 and stores the plurality of fingerprint registration information. When subsequent users need to perform identity recognition, the multiple fingerprint registration information is used for fingerprint comparison to identify the user's identity. Algorithms and related details for generating registration information based on fingerprint images are well known to those skilled in the field of fingerprint recognition and will not be described in detail here.

In another embodiment, the processing unit 21 stitches the multiple qualified fingerprint images 30 into a complete fingerprint image 31 as shown in FIG. 11, and generates registration information according to the complete fingerprint image 31. The technical content of splicing multiple fingerprint images into a complete fingerprint image is well known to those skilled in the field of fingerprint recognition and will not be described in detail here.

In the embodiment shown in FIG. 1B, step S30 includes steps S32 and S34. Step S32 is to determine whether there is a difference between the fingerprint image 30 and the previous fingerprint image 30. An embodiment of step S32 includes a subtraction operation between a fingerprint image 30 and a previous fingerprint image 30. For example, the size of the fingerprint image is 80 * 80 pixels. The method to determine whether there is any difference between the fingerprint image of the Nth image and the previous one (that is, the N-1th image) is to first convert both fingerprint images into a grayscale distribution, where the pixel value of each pixel is, for example, The value is 0 to 256. Next, subtract the pixel values of the two fingerprint images to obtain 6400 (80 * 80) difference values, and calculate the sum of these 6400 difference values. The sum of the differences is used to compare with a sum threshold. When the sum of the differences is greater than the sum of the weights, it is determined that the two fingerprint images before and after are different. In other embodiments, the sum of the above differences may be divided by 6400 to obtain a difference average, and the difference average may be compared with an average threshold. When the difference is larger than the average threshold value on average, it is judged that the two fingerprint images before and after are different.

If the determination result of step S32 is YES, then proceed to step S34. If the determination result of step S32 is NO, then step S50 is performed to discard the fingerprint image 30. During the fingerprint registration process for the finger 10, it is desirable to obtain fingerprints of all areas of the finger 10 as much as possible. By step S32, it is possible to avoid storing multiple identical fingerprint images. If there is a difference between a fingerprint image 30 and a previous fingerprint image 30, it means that the two fingerprint images 30 are different regions corresponding to the finger 10.

Step S34 is determining whether the fingerprint density D of the fingerprint image 30 falls within an allowable range. The fingerprint density D of the fingerprint image 30 may be calculated in various ways. In some embodiments, the number of ridges (ridges) covered by the two diagonal lines (or more straight lines) of the fingerprint image 30 is used. The number of valleys, or the number of times that the peaks and valleys alternate, is used as the fingerprint density. The allowable range of the fingerprint density D can be determined by the fingerprint density D1 of the first fingerprint image 30 obtained by the fingerprint sensor 20 when sensing the finger 10. For example, if the fingerprint density D1 is 10, the allowable range is between a preset range of 10 (for example, 30% above and below), that is, 7-13. In general, the rapid movement of a finger in the fingerprint sensor 20 easily produces a deformed fingerprint image, which cannot be used to generate fingerprint registration information. Since the fingerprint density of such a deformed fingerprint image is low, by determining whether the density of the fingerprint image 30 falls within an allowable range, the deformed fingerprint image can be excluded.

When the determination in step S34 is YES, it means that the fingerprint image 30 is qualified. Then, step S40 is performed.

According to step S30 shown in FIG. 1B, the steps of determining that a fingerprint image 30 is qualified include determining that there is a difference between a fingerprint image 30 and a previous fingerprint image, and determining that the fingerprint density of the fingerprint image falls within one Allowable range. However, step S30 in FIG. 1B is only an embodiment, and is not intended to limit the present invention. In other embodiments, the order of steps 32 and S34 may be reversed. Alternatively, step S30 may add more judgment conditions. Alternatively, step S30 may reduce the determination conditions. For example, step 30 includes only one of steps S32 and S34.

According to the method of the present invention, the finger 10 is moved on the fingerprint sensor 20 in a spiral path, instead of leaving and touching the fingerprint sensor multiple times, so the fingerprint sensor 20 can collect multiple photos in a short time. Fingerprint image 30, registration time can be effectively reduced. The finger 10 moves in a spiral path, and the force of the finger pressing is generally relatively consistent, and the speed of the finger movement is not too fast, and the deformed fingerprint image is not captured. Therefore, the fingerprint image obtained by the method of the present invention Image 30 is better for subsequent fingerprint comparison. The finger 10 moves on the fingerprint sensor 20 in a spiral path, and it is relatively easy for all fingerprints of the finger 10 to pass through the fingerprint sensor 20. Therefore, it is easier to obtain a complete fingerprint image by the method of the present invention.

Please refer to FIG. 4. In one embodiment, the instruction is a group of characters 50 displayed on the display 40. The content of the group of characters 50 may be, for example, "Please move your finger in a spiral manner on the fingerprint sensor".

Please refer to FIG. 5. In one embodiment, the indication is a spiral curve 51 displayed on the display 40 to prompt the user to move his finger according to the spiral curve 51. In one embodiment, the display device 40 may display a schematic position 500 of the fingerprint sensor.

In other embodiments, the indication includes a spiral curve and a direction mark, and the direction mark is used to indicate whether the direction of the spiral curve is from inside to outside or outside to inside, to prompt the user to move his finger. direction. For example, the indication 520 shown in FIG. 6 includes a spiral curve 52 and a direction mark 524. The direction mark 524 is an arrow and is located at one end of the spiral curve 52. The direction mark 524 is used to indicate that the inner end point 521 of the spiral curve 52 is the starting point, and the outer end point 522 of the spiral curve 52 is the end point. Alternatively, for example, the indication 530 shown in FIG. 7 includes a spiral curve 53 and a direction mark 534. The direction mark 534 is located at one end of the spiral curve 53. The direction symbol 534 is an arrow, which is used to indicate that the peripheral end point 532 of the spiral curve 53 is the starting point, and the center end point 531 of the spiral curve 53 is the end point.

In FIG. 6, the direction of the indication 520 is a clockwise direction. In the embodiment shown in FIG. 8, the direction of the indication 540 is counterclockwise.

In other embodiments, the indication is an animation. Taking the spiral curve 51 shown in FIG. 5 as an example, the display 40 displays the instruction by displaying the spiral curve 51 from the inside to the outside, or displaying the spiral curve 51 from the outside to the inside. As shown in FIGS. 9A to 9C, when displaying the spiral curve 51, the spiral curve 51 is displayed from the inside to the outside. For example, first, the first line segment 511 is displayed as shown in FIG. 9A, and then as shown in FIG. 9B. The first line segment 511 and the second line segment 512, and then the first line segment 511, the second line segment 512, and the third line segment 513 are displayed as shown in FIG. 9C, and finally a complete spiral-shaped curve 51 is displayed as shown in FIG.

For another embodiment, please refer to FIGS. 10A to 10C and FIG. 5. When the display 40 displays the spiral curve 51, the display 40 displays the spiral curve 51 from the outside to the inside. Four line segments 514, then the fourth line segment 514 and the fifth line segment 515 are shown in FIG. 10B, and then the fourth line segment 514, the fifth line segment 515, and the sixth line segment 516 are shown in FIG. 10C, and finally the complete spiral is shown in FIG. 5状 平面 51。 Shaped curve 51.

The above description is only an embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed by the embodiments as above, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field of the art, Within the scope not departing from the technical solution of the present invention, when the above disclosed technical content can be used to make a few changes or modifications to equivalent equivalent embodiments, as long as it does not depart from the technical solution of the present invention, it is in accordance with the technical essence of the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments still fall within the scope of the technical solution of the present invention.

10‧‧‧ finger

20‧‧‧Fingerprint sensor

21‧‧‧processing unit

22‧‧‧Storage Media

30‧‧‧Fingerprint image

40‧‧‧ Display

50‧‧‧ text

51,52,53,54‧‧‧spiral curve

511‧‧‧first line segment

512‧‧‧Second Line Segment

513‧‧‧ Third line segment

514‧‧‧Fourth line segment

515‧‧‧Fifth line segment

516‧‧‧Sixth line segment

520, 530, 540‧‧‧ instructions

524, 534, 566‧‧‧ direction signs

60‧‧‧Fingerprint image

70‧‧‧ fingerprint image

71, 72‧‧‧ Anamorphic fingerprint image

FIG. 1A is an embodiment of a flowchart of the present invention. FIG. 1B is a flowchart illustrating how the present invention determines whether a fingerprint image is qualified. FIG. 2 is an operation diagram of a user according to instructions during the implementation of the present invention. FIG. 3 is a schematic diagram of a fingerprint image obtained during the implementation of the present invention. FIG. 4 is a schematic diagram of a first embodiment of the indication of the present invention. FIG. 5 is a schematic diagram of a second embodiment of the present invention. FIG. 6 is a schematic diagram of a third embodiment of the present invention. FIG. 7 is a schematic diagram of a fourth embodiment of the present invention. FIG. 8 is a schematic diagram of a fifth embodiment of the present invention. 9A to 9C are schematic diagrams of a first embodiment of a display instruction process of the present invention. 10A to 10C are schematic diagrams of a second embodiment of a display instruction process of the present invention. FIG. 11 is a schematic diagram of stitching a complete fingerprint image according to the present invention. FIG. 12 is a block diagram of an electronic device according to the present invention. FIG. 13 is a schematic diagram of a fingerprint image obtained by a conventional pressing method. FIG. 14 is a schematic diagram of a fingerprint image obtained by a conventional scanning and sliding method. FIG. 15 is a schematic diagram of deformation of a fingerprint image generated by a conventional sweep-slide method.

Claims (21)

A fingerprint registration method includes: (a) providing an instruction for prompting a user to move a finger on a fingerprint sensor in a spiral path; (b) moving the finger on the fingerprint sensor At this time, the fingerprint sensor senses the finger to obtain multiple fingerprint images; and (c) determines whether the fingerprint image is qualified, wherein the fingerprint image is not an image obtained by splicing. The fingerprint registration method according to claim 1, wherein the indication includes a spiral curve. The fingerprint registration method according to claim 2, wherein the indication further includes a direction mark, which is used to indicate whether the direction of the spiral curve is from inside to outside or outside to inside, to prompt the user to move his finger Direction. The fingerprint registration method according to claim 2, wherein the method for displaying the instruction is to display the spiral curve from the inside out, or display the spiral curve from the outside to the inside. The fingerprint registration method according to claim 1, wherein the instruction includes a set of text. The fingerprint registration method according to claim 1, wherein in step c, the step of determining that the fingerprint image is qualified includes: determining that there is a difference between the fingerprint image and the fingerprint image obtained by a previous one. The fingerprint registration method according to claim 1, wherein in step c, the step of determining that the fingerprint image is qualified includes: determining that the fingerprint density of the fingerprint image falls within an allowable range. The fingerprint registration method according to claim 1, wherein a plurality of the qualified fingerprint images are obtained after performing step c multiple times, and the method further comprises stitching a complete set of the fingerprint images based on the multiple qualified fingerprint images into a complete Fingerprint image. The fingerprint registration method according to claim 1, comprising performing step c multiple times and accumulating the number of qualified fingerprint images. When the number of the qualified fingerprint images reaches a preset value, the The fingerprint sensor stops the motion of sensing the finger. The fingerprint registration method according to claim 1, wherein the instruction is displayed on a display. The fingerprint registration method according to claim 1, further comprising generating a plurality of fingerprint registration information based on the plurality of fingerprint images generated by the fingerprint sensor. An electronic device includes: a fingerprint sensor; a display that displays an instruction when the electronic device performs fingerprint registration; and a processing unit that is coupled to the fingerprint sensor and the display, the The processing unit is configured to provide the indication to the display; wherein the indication is used to prompt a user to move a finger on the fingerprint sensor in a spiral path, so that the fingerprint sensor obtains multiple fingerprint images, the The processing unit determines whether the fingerprint image obtained by the fingerprint sensor is qualified, wherein the fingerprint image is not an image obtained by splicing. The electronic device according to claim 12, wherein the indication includes a spiral curve. The electronic device according to claim 12, wherein the indication further includes a direction mark, which is used to indicate whether the direction of the spiral curve is from inside to outside or outside to inside, to prompt the user to move his finger direction. The electronic device according to claim 13, wherein the method for displaying the instruction on the display is to display the spiral curve from the inside to the outside, or to display the spiral curve from the outside to the inside. The electronic device according to claim 12, wherein the instruction includes a set of text. The electronic device according to claim 12, wherein the step of the processing unit determining that the fingerprint image is qualified includes: determining that there is a difference between the fingerprint image and the fingerprint image obtained by a previous one. The electronic device according to claim 12, wherein the step of the processing unit determining that the fingerprint image is qualified includes: determining that the fingerprint density of the fingerprint image falls within an allowable range. The electronic device according to claim 12, wherein the processing unit determines a plurality of qualified fingerprint images from the plurality of fingerprint images, and the processing unit further stitches the fingerprint images into one according to the plurality of qualified fingerprint images. Full fingerprint image. The electronic device according to claim 12, wherein the processing unit repeats the step of determining whether the fingerprint image obtained by the fingerprint sensor is qualified, and accumulates the number of qualified fingerprint images. When the number of the fingerprint images reaches a preset value, the processing unit notifies the fingerprint sensor to stop the motion of sensing the finger. The electronic device according to claim 12, wherein the processing unit generates a plurality of fingerprint registration information according to the plurality of fingerprint images.