Fingerprint identification method, touch data processing device and terminal

Abstract

The application discloses a fingerprint identification method, a touch data processing device and a terminal fingerprint identification method, which comprises the following steps: obtaining a plurality of image blocks from a to-be-verified image, wherein each image block is a part of the to-be-verified image, and the union of the plurality of image blocks constitutes the to-be-verified image; for each image block, obtaining the matching area of the image block and a plurality of input images respectively, and taking the maximum value in the matching areas of the image block and the input images as the maximum matching area of the image block; obtaining the total matching area of the to-be-verified image and the plurality of input images according to the maximum matching area of each image block; and determining that the to-be-verified image corresponds to an identifiable user according to the total matching area, so that the accuracy of fingerprint identification is improved.

Description

Technical Field

[0001] This invention relates to the fields of touch recognition and other technologies, and particularly to fingerprint recognition methods, touch data processing devices, and terminals. Background Technology

[0002] like Figure 1 As shown, capacitive fingerprint recognition technology forms a fingerprint image based on the capacitance differences between the ridges and valleys of the fingerprint, and then performs identification and matching after obtaining the fingerprint image. This technology is widely used in various mobile smart terminals, door locks, and automobiles, providing them with a relatively reliable biometric identification method.

[0003] like Figure 2 As shown, the key to existing capacitive fingerprint recognition technology lies in fingerprint image matching. First, a fingerprint image is recorded and saved. During recognition, a new image to be verified is acquired and matched against the previously recorded image. Generally, if the same finger is used for recording and verification, the result should be a match; otherwise, it will not match. For example, if 10 fingerprint images are recorded and only one image is used for verification, 10 matches are required, and a single match is considered a successful recognition.

[0004] like Figure 3 As shown, the fingerprint sensor is located on the side of a mobile terminal (such as a mobile phone). With the increasing thinness and miniaturization of various mobile smart terminals, the capacitive fingerprint sensor also needs to reduce its area. This reduces the effective fingerprint area available for matching, resulting in a more elongated image and increased false matches, severely impacting the recognition rate and increasing the risk of mismatches. Figure 4 As shown, when the image obtained from fingerprint recording is at a 90-degree angle to the image to be verified, the overlap area is smaller, making matching more difficult. For example... Figure 5 When the same image to be verified is compared with different input images, the matching rate is 30%. However, the matching rate of the image to be verified and the three input images 1-3 should be 90%. Furthermore, when the matching rate threshold for successful recognition is 50%, misjudgment of recognition failure will occur. Therefore, there is an urgent need for a fingerprint recognition method that can solve the above-mentioned recognition defects. Summary of the Invention

[0005] In view of the above problems, the purpose of this invention is to provide a fingerprint recognition method, a touch data processing device, and a terminal, thereby solving the aforementioned technical defects.

[0006] According to one aspect of the present invention, a fingerprint recognition method is provided, comprising: obtaining a plurality of image blocks based on an image to be verified, wherein each of the plurality of image blocks is a part of the image to be verified, and the union of the plurality of image blocks constitutes the image to be verified; for each image block, obtaining its matching area with a plurality of recorded images, and taking the maximum value among the matching areas of the image block with each of the recorded images as the maximum matching area of ​​the image block; obtaining the total matching area of ​​the image to be verified with the plurality of recorded images based on the maximum matching area of ​​each of the image blocks; and determining that the image to be verified corresponds to an identifiable user based on the total matching area.

[0007] Optionally, it further includes: obtaining a matching rate based on the total matching area, determining whether the matching rate reaches a preset value, and if it reaches the preset value, determining that the recognition is successful; if it does not reach the preset value, determining that the recognition is unsuccessful, wherein the matching rate is the percentage of the total matching area of ​​the image to be verified and the plurality of entered images to the area of ​​the fingerprint touch area.

[0008] Optionally, the plurality of image blocks are distributed sequentially along the long side of the image to be verified, with adjacent image blocks overlapping or not overlapping.

[0009] Optionally, all of the image blocks are squares.

[0010] Optionally, dividing the image to be verified into several image blocks along the long side includes: dividing the length of the long side of the image to be verified by the length of the short side of the image to be verified and rounding it up to obtain the number of image blocks.

[0011] Optionally, the total matching area is the difference between the sequential sum of the maximum matching areas of each image block and the sequential sum of the maximum matching areas of the intersections of each image block and other image blocks.

[0012] Optionally, the maximum matching area of ​​the intersection of each image block and other image blocks is |Ai∩Aj|*(P(Ai) / |Ai|+P(Aj) / |Aj|) / 2, where P() represents the maximum matching area of ​​the image block, Ai and Aj represent two different image blocks among the plurality of image blocks, and Ai∩Aj represents the overlapping part of two different image blocks among the plurality of image blocks.

[0013] According to another aspect of the present invention, a touch data processing apparatus is provided, comprising: a memory for storing a plurality of acquired input images; and a processor configured to: obtain a plurality of image blocks based on an image to be verified, wherein each of the plurality of image blocks is a part of the image to be verified, and the union of the plurality of image blocks constitutes the image to be verified; for each image block, obtain its matching area with the plurality of input images, and take the maximum value among the matching areas of the image block with each of the input images as the maximum matching area of ​​the image block; obtain the total matching area of ​​the image to be verified with the plurality of input images based on the maximum matching area of ​​each of the image blocks; and determine that the image to be verified corresponds to an identifiable user based on the total matching area.

[0014] According to another aspect of the present invention, a terminal is provided, comprising a touch display control device and a display panel, wherein the touch display control device comprises a display driving module, a touch scanning module, and the touch data processing device as described in claim 8, wherein the display driving module is used to perform a display driving scan on the display panel during a display driving phase; the touch scanning module is used to enter a touch scanning phase under the control of the display driving module, and to perform a touch scan on the touch panel during the touch scanning phase to obtain an input image and an image to be verified.

[0015] Optionally, the width of the fingerprint touch area of ​​the terminal is smaller than the width of a single fingerprint image, and / or the length of the fingerprint touch area is smaller than the length of a single fingerprint image.

[0016] The fingerprint recognition method provided by this invention divides the image to be verified into multiple image blocks and provides a special algorithm to remove the matching area of ​​the overlapping parts between the image blocks, thereby obtaining the total matching area. Based on the total matching area, the image to be verified is determined to correspond to an identifiable user, thus improving the accuracy of fingerprint recognition. Attached Figure Description

[0017] The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0018] Figure 1 This diagram illustrates finger pressing in capacitive fingerprint recognition according to the prior art.

[0019] Figure 2 A schematic diagram of fingerprint acquisition in capacitive fingerprint recognition according to the prior art is shown.

[0020] Figure 3 A schematic diagram of the structure of a mobile terminal according to the prior art is shown.

[0021] Figure 4A schematic diagram showing the comparison of the thickness of the side fingerprint sensor when the entered image and the image to be verified are recognized at a 90-degree angle according to the prior art.

[0022] Figure 5 This diagram illustrates the matching rate when the input image and the image to be verified are recognized at a 90-degree angle according to the prior art, and is compared with different input images.

[0023] Figure 6 A block diagram of a mobile terminal structure provided in an embodiment of this application is shown.

[0024] Figure 7 A flowchart of the method for obtaining the matching rate between the input image and the image to be verified provided in an embodiment of this application is shown.

[0025] Figure 8 This illustration shows a schematic diagram of image segmentation provided in an embodiment of this application.

[0026] Figure 9 A flowchart of the fingerprint recognition method provided in an embodiment of this application is shown. Detailed Implementation

[0027] Various embodiments of the invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements or modules are indicated by the same or similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale.

[0028] It should be understood that, in the following description, "circuit" may include single or combined hardware circuits, programmable circuits, state machine circuits, and / or elements capable of storing instructions executed by the programmable circuit. When an element or circuit is said to be "connected" to another element or "connected" between two nodes, it may be directly coupled or connected to the other element, or there may be intermediate elements; the connection between elements may be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected" to another element, it means that there are no intermediate elements between them.

[0029] Furthermore, certain terms are used in this patent specification and claims to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This patent specification and claims do not distinguish components based on differences in name, but rather on differences in function.

[0030] Furthermore, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0031] Figure 6 A block diagram of a mobile terminal structure provided in an embodiment of this application is shown.

[0032] like Figure 6 As shown, the terminal includes a touch display control device 10 and a display panel 20. The touch display control device 10 includes a display driving module 101, a touch scanning module 102, and a touch data processing module 103. The width of the fingerprint touch area of ​​the terminal is smaller than the width of a single fingerprint image, and / or the length of the fingerprint touch area is smaller than the length of a single fingerprint image.

[0033] The display driver module 101 is used to perform display driver scanning on the display panel during the display driver phase. The touch scanning module 102 is used to enter the touch scanning phase under the control of the display driver module 101, and to perform touch scanning on the touch panel during the touch scanning phase to obtain touch input images and images to be verified for touch detection. The touch data processing module 103 includes: a memory for storing multiple input images; and a processor configured to: obtain a plurality of image blocks based on the image to be verified, wherein each of the plurality of image blocks is a part of the image to be verified, and the union of the plurality of image blocks constitutes the image to be verified; for each image block, obtain its matching area with the plurality of input images, and take the maximum value among the matching areas of the image block with each of the input images as the maximum matching area of ​​the image block; obtain the total matching area of ​​the image to be verified with the plurality of input images based on the maximum matching area of ​​each of the image blocks; and determine that the image to be verified corresponds to an identifiable user based on the total matching area.

[0034] Figure 7 A flowchart illustrating the method for calculating the matching rate between the input image and the image to be verified, provided in an embodiment of this application, is shown.

[0035] like Figure 7As shown, the method for obtaining the matching rate between the image to be verified and the recorded image provided in this application embodiment is executed by the aforementioned data processing module, and the matching rate calculation method may specifically include the following steps:

[0036] S1: Obtain several image blocks based on the image to be verified.

[0037] In step S1, several image blocks A1, A2...An are obtained based on the image to be verified. Each of the several image blocks is a part of the verification image, and the union of the several image blocks constitutes the image to be verified.

[0038] Figure 8 This illustration shows a schematic diagram of image segmentation provided in an embodiment of this application.

[0039] like Figure 8 As shown, the above n image patches may or may not overlap, ensuring that each image patch contains all the images to be verified, represented by a set.

[0040] S = A1∪A2∪...∪An, where the areas of each image patch are |A1|, |A2|, ..., |An|, and the overlapping areas are |Ai∩Aj|, (where i and j are 1, 2, ..., n).

[0041] In one embodiment, the segmented image blocks are preferably square; specifically, the segmentation method is as follows: let the longer side be X and the shorter side be Y, then take n = ceil(X / Y), where ceil is the floor function. For example, if X = 110 and Y = 30, then n = ceil(110 / 30) = 4. Figure 8 As shown in the right image, the fourth non-overlapping block is 20 units long. To also form a square, it needs to overlap with the third block by 10 units. In this method, at most two image blocks will overlap; therefore, there will be no overlap between any three image blocks mentioned above.

[0042] S2: For each image block, obtain its matching area with multiple recorded images, and take the maximum value among the matching areas of the image block and each recorded image as the maximum matching area of ​​the image block.

[0043] In step S2, the matching area between image block Ai and the input image Ej is defined as P(Ai,Ej), and P(Ai) = {the largest P(Ai,Ej) among all Ej}. It should be noted that P(Ai,Ej) can be achieved by existing publicly available methods for calculating the overlapping area of ​​matching images, which will not be elaborated on in this application.

[0044] S3: The total matching area between the image to be verified and the plurality of recorded images is obtained based on the maximum matching area of ​​each of the image blocks.

[0045] In step 3, according to the inclusion-exclusion principle of sets, the matching area is the difference between the sequential sum of the maximum matching areas of each image patch and the sequential sum of the maximum matching areas of the intersections of each image patch with other image patches. That is, the final matching area of ​​the image S to be verified can be corrected to P(S) = P(A1∪A2∪...∪An) = ∑P(Ai) - ∑P(Ai∩Aj), where P(Ai∩Aj) is defined as: P(Ai∩Aj) = |Ai∩Aj|*(P(Ai) / |Ai|+P(Aj) / |Aj|) / 2, where i and j are two distinct integers from 1 to n. Based on the above expression, the matching area of ​​the overlapping parts between the image patches can be removed, thus obtaining the total matching area. It should be noted that there may be no overlapping parts between the image patches; this formula can also calculate the total matching area when there is no overlap between the image patches.

[0046] In this context, the union symbol ∪ indicates that the resulting image patch is a set composed of these two image patches, and the intersection symbol ∩ indicates that the resulting image patch is the overlapping portion of these two image patches.

[0047] Figure 9 A flowchart of the fingerprint recognition method provided in an embodiment of this application is shown.

[0048] like Figure 9 As shown, the fingerprint recognition method performs fingerprint recognition on the image to be verified based on the stitched image obtained above, specifically including the following steps:

[0049] S101: Acquire the image to be verified.

[0050] In step S101, the touch scanning module 102 enters the touch scanning stage under the control of the display driving module 101, and performs touch scanning on the touch panel to acquire the touch image to be verified during the touch scanning stage.

[0051] S102: Determine that the matching rate between the image to be verified and the input image has reached the preset value.

[0052] In step S102, the image to be verified is compared with the stitched image. Using the above-described method for obtaining the matching rate between the image to be verified and the input image, it is determined whether the matching rate has reached a preset value based on the obtained matching rate between the image to be verified and the input image. In one embodiment, the preset value is, for example, 50%. If the preset value is reached, it is determined that the recognition is successful; if the preset value is not reached, it is determined that the recognition has failed.

[0053] This application obtains a more accurate matching rate by using the above-mentioned method for obtaining the matching rate between the image to be verified and the recorded image, and performs fingerprint recognition based on the matching rate, making the recognition result more accurate and the recognition rate higher.

[0054] It should be noted that those skilled in the art will understand that the terms “during,” “when,” and “when…” used herein in relation to circuit operation are not strict terms indicating an action that occurs immediately upon the commencement of a startup action, but rather that there may be some small but reasonable delays, such as various propagation delays, between the startup action and the reaction action initiated by it. The terms “approximately” or “substantially” used herein mean that an element value is expected to be close to the declared value or position. However, as is well known in the art, there are always small deviations that make it difficult for the value or position to be strictly the declared value. It has been properly determined in the art that a deviation of at least ten percent (10%) (or at least twenty percent (20%) for semiconductor doping concentration) is a reasonable deviation from the described accurate ideal target. When used in conjunction with signal states, the actual voltage value or logic state of the signal (e.g., “1” or “0”) depends on whether positive or negative logic is used.

[0055] As described above, these embodiments of the present invention do not exhaustively describe all details, nor do they limit the invention to specific embodiments. Clearly, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to effectively utilize the invention and its modifications. The scope of protection of this invention should be determined by the scope defined in the claims and their equivalents.

Claims

1. A method for fingerprint identification, comprising: obtaining a plurality of image blocks from a to-be-verified image, each of the image blocks being a part of the to-be-verified image, and the union of the image blocks constituting the to-be-verified image; for each of the image blocks, obtaining a matching area of the image block with each of a plurality of enrolled images, and taking the maximum of the matching areas of the image block with the enrolled images as a maximum matching area of the image block; obtaining a total matching area of the to-be-verified image with the plurality of enrolled images according to the maximum matching areas of the image blocks; and determining that the to-be-verified image corresponds to an identifiable user according to the total matching area, wherein at most two of the image blocks overlap, the total matching area being a difference between a sequential summation of the maximum matching areas of the image blocks and a sequential summation of maximum matching areas of intersections of each of the image blocks with other image blocks.

2. The method of claim 1, further comprising: obtaining a matching rate according to the total matching area, and determining whether the matching rate reaches a preset value, if yes, determining that the identification is successful; and if no, determining that the identification is unsuccessful, wherein the matching rate is a percentage of the total matching area of the to-be-verified image with the plurality of enrolled images to an area of a fingerprint touch region. the image blocks are sequentially distributed along a long side direction of the to-be-verified image, and adjacent image blocks overlap or do not overlap.

3. The method of claim 1, wherein, the image blocks are all squares.

4. The method of claim 3, wherein, the to-be-verified image is divided into the image blocks along the long side direction includes: dividing the to-be-verified image into the image blocks according to a quotient obtained by dividing a long side length of the to-be-verified image by a short side length of the to-be-verified image.

5. The method of claim 4, wherein, the maximum matching area of the intersection of each of the image blocks with other image blocks is |Ai ∩ Aj| * (P(Ai) / |Ai| + P(Aj) / |Aj| ) / 2, P() represents the maximum matching area of the image block, Ai and Aj represent two different image blocks of the image blocks, and Ai ∩ Aj represents an overlapping part of the two different image blocks.

6. The method of claim 1, wherein, comprising:

7. A touch data processing device, wherein, a memory storing a plurality of obtained enrolled images; and a processor configured to: obtain a plurality of image blocks from a to-be-verified image, each of the image blocks being a part of the to-be-verified image, and the union of the image blocks constituting the to-be-verified image; for each of the image blocks, obtain a matching area of the image block with each of a plurality of enrolled images, and take the maximum of the matching areas of the image block with the enrolled images as a maximum matching area of the image block; obtain a total matching area of the to-be-verified image with the plurality of enrolled images according to the maximum matching areas of the image blocks; and determine that the to-be-verified image corresponds to an identifiable user according to the total matching area, wherein at most two of the image blocks overlap, the total matching area being a difference between a sequential summation of the maximum matching areas of the image blocks and a sequential summation of maximum matching areas of intersections of each of the image blocks with other image blocks. ​ ​ ​ 8. A terminal comprising a touch display control device and a display panel, the touch display control device comprising a display driving module, a touch scanning module and the touch data processing device of claim 7, wherein, the display driving module is configured to perform display driving scanning on the display panel in a display driving phase; the touch scanning module is configured to enter a touch scanning phase under the control of the display driving module, and perform touch scanning on the touch panel in the touch scanning phase to obtain an entry image and a to-be-verified image.

9. The terminal of claim 8, a width of a fingerprint touch area of the terminal is less than a width of a single fingerprint image, and / or a length of the fingerprint touch area is less than a length of a single fingerprint image.

Images