TWI788952B - Fingerprint image processing method, fingerprint chip, and electronic device - Google Patents

Abstract

Embodiments of the present application provide a fingerprint image processing method, a fingerprint chip, and an electronic device, which are used to reduce the cost of fingerprint image analysis and improve the adaptability of fingerprint image analysis to application scenarios. The fingerprint image processing method includes: collecting an original fingerprint image and obtaining an original fingerprint image data; performing average filtering on the original fingerprint image data continuously at least twice, and recording a first image data obtained by a first average filtering and a second image data obtained by a last average filtering; performing preset operations on the first image data and the second image data to obtain a final fingerprint image data; and generating, based on the final fingerprint image data obtained by calculation, a fingerprint image that can be used for matching and identification.

Description

Fingerprint image processing method, fingerprint chip and electronic equipment

The present application relates to the technical field of fingerprint identification, in particular to a fingerprint image processing method, a fingerprint chip and electronic equipment.

Optical fingerprint recognition can be used to realize unlocking, payment, authority authentication and other functions, and it is more and more widely used in the field of smart phones or electronic devices.

In the process of realizing the optical fingerprint identification function, it is often necessary to eliminate the background noise in the fingerprint pressing image. As shown in FIG. 1 , in related technologies, a tool without fingerprints is often used to press the optical sensor to collect background data (as shown in the left image of FIG. 1 ) in advance, and the background data is pre-stored. After obtaining the fingerprint pressing image obtained by pressing the optical sensor with the finger (as shown in the middle image in Figure 1), the background noise in the fingerprint pressing image is eliminated by relying on the pre-stored background data to obtain the final fingerprint image (as shown in Figure 1 1 shown in the image on the right).

In related technologies, background data needs to be collected and stored in advance, which is time-consuming and labor-intensive. Moreover, the pre-stored background data is often collected in a specific application scenario, and it is difficult to adapt to multiple application scenarios. When the application scene changes, the pre-stored background data does not match the new application scene, and background noise cannot be eliminated better, which affects the quality of the fingerprint image.

Embodiments of the present application provide a fingerprint image processing method, a fingerprint chip and electronic equipment, which are used to reduce the cost of fingerprint image analysis and improve the adaptability of fingerprint image analysis to application scenarios.

The first aspect of the embodiment of the present application provides a fingerprint image processing method, which may include:

Collect the original fingerprint image and obtain the original fingerprint image data;

Continuously performing at least two average value filters on the original fingerprint image data, recording the first image data obtained by the first average value filter and the second image data obtained by the last average value filter;

performing a preset operation on the first image data and the second image data to obtain fingerprint image data;

Based on the fingerprint image data obtained by the final calculation, a fingerprint image that can be used for matching and identification is generated.

In some embodiments, as a possible implementation manner, in the embodiment of the present application, performing preset operations on the first image data and the second image data to obtain fingerprint image data may include:

Performing a subtraction operation on the pixel values of elements with the same number of rows and columns in the first image data and the second image data to obtain fingerprint image data.

In some embodiments, as a possible implementation manner, in the embodiment of the present application, the fingerprint image data is obtained by performing preset operations on the first image data and the second image data, including:

Performing a division operation on the pixel values of elements with the same number of rows and columns in the first image data and the second image data to obtain fingerprint image data.

In some embodiments, as a possible implementation manner, the fingerprint image processing method in the embodiment of the present application may also include:

Perform quantization processing on the fingerprint image data, and/or perform enhancement processing; the quantization processing includes one or more of linear quantization processing, histogram equalization processing; the enhancement processing includes Gaussian filtering processing, texture filtering processing , one or more of gabor filter processing.

In some embodiments, as a possible implementation manner, in the embodiment of the present application, performing mean value filtering on the original fingerprint image data at least twice continuously is as follows:

The mean value filtering is performed twice continuously on the original fingerprint image data.

The second aspect of the embodiment of the present application provides a fingerprint chip, which may include:

The collection module is used to collect the original fingerprint image by using the optical fingerprint sensor, and obtain the original fingerprint image data;

A filtering module, configured to continuously perform at least two mean value filters on the original fingerprint image data, and record the first image data obtained by the first mean value filter and the second image data obtained by the last mean value filter;

The calculation module is used to perform preset calculations on the first image data and the second image data to obtain fingerprint image data that can be used for matching and identification, and generate fingerprint image data that can be used for matching and identification according to the fingerprint image data obtained through the final calculation. Recognized fingerprint image.

In some embodiments, as a possible implementation manner, in the embodiment of the present application, the computing module may include:

The first operation unit is used for subtracting the pixel values of elements with the same number of rows and columns in the first image data and the second image data to obtain fingerprint image data.

In some embodiments, as a possible implementation manner, in the embodiment of the present application, the computing module may include:

The second operation unit is used for performing division operation on the pixel values of elements with the same number of rows and columns in the first image data and the second image data to obtain fingerprint image data.

In some embodiments, as a possible implementation manner, the fingerprint chip in the embodiment of the present application may also include:

Supplementary computing module, used to perform quantization processing and/or enhancement processing on fingerprint image data; quantization processing includes one or more of linear quantization processing and histogram equalization processing; enhancement processing includes Gaussian filtering processing, texture filtering One or more of processing and Gabor filtering processing.

The third aspect of the embodiment of the present application provides an electronic device, the electronic device includes an optical fingerprint sensor and a processor, the optical fingerprint sensor is used to generate fingerprint pressing original fingerprint image data, and the processor is used to execute The computer program stored in the memory implements the steps in the first aspect and any possible implementation manner of the first aspect.

It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

In the embodiment of the present application, after the fingerprint chip acquires the original fingerprint image data, it can continuously perform mean value filtering on the original fingerprint image data at least twice, and record the first image data obtained by the first mean value filtering and the last mean value The second image data obtained by filtering, and finally the preset operation is performed on the first image data and the second image data to obtain a fingerprint image that can be directly used for fingerprint matching and identification. Compared with related technologies, this application does not need to collect and store background data, which saves the cost of fingerprint image analysis, and does not need to rely on fixed background data to eliminate background noise, which improves the adaptability to application scenarios.

Embodiments of the present application provide a fingerprint image processing method, a fingerprint chip and electronic equipment, which are used to reduce the cost of fingerprint image analysis and improve the adaptability of fingerprint image analysis to application scenarios.

In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiment of the application will be clearly and completely described below in conjunction with the drawings in the embodiment of the application. Obviously, the described embodiment is only It is an embodiment of a part of the application, but not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

The terms "first", "second", "third", "fourth" and the like in the specification and patent scope of this application and the above drawings are used to distinguish similar objects, but not necessarily to describe specific sequence or sequence. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device comprising a sequence of steps or elements is not necessarily limited to the expressly listed instead, may include other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

For ease of understanding, the specific process in the embodiment of the present application is described below. Please refer to FIG. 2. An embodiment of a fingerprint image processing method in the present application may include:

Step S201: collect the original fingerprint image, and obtain the original fingerprint image data;

After the finger presses the optical fingerprint sensor, the optical fingerprint sensor can generate an original fingerprint image based on the received photoelectric signal, and acquire original fingerprint image data based on the original fingerprint image. In this embodiment, the original fingerprint image data is an image matrix, such as an M*N matrix, where M is the number of image rows, and N is the number of image columns. The value of each element in the matrix is a pixel value, and the expression form of the pixel value is related to the number of data bits. 10-bit data is a value from 0 to 1024; 12-bit data is a value from 0 to 4096. Wherein, there is background noise in the fingerprint pressing image acquired at this stage, and the background noise needs to be further eliminated.

In other embodiments, other data representing fingerprint information may also be used, which is not limited here. After the finger presses the touch, due to the difference in the valleys and ridges of the fingerprint lines, the voltage of the analog signal will be different. After the analog signal is converted into digital information, a pixel matrix is obtained. The pixel matrix represents the basic line information of the finger.

Step S202: Continuously perform at least two average value filtering on the original fingerprint image data, and record the first image data obtained by the first average value filter and the second image data obtained by the last average value filter;

In this embodiment, in order to eliminate background noise, the fingerprint chip in the embodiment of the present application can continuously perform at least two average value filters on the original fingerprint image data obtained in step S201, and record the first image obtained by the first average value filter data and the second image data obtained by the last mean filtering.

In some embodiments, taking two consecutive mean filtering as an example, the specific process is: performing the first mean filtering on the original image data to obtain the filtered data fliter_data1 (the first image data), and then performing filtering on the fliter_data1 mean filtering to obtain filtered data fliter_data2 (second image data).

It can be understood that the more times of continuous mean filtering, the less detailed information such as noise and texture in the image can be obtained. In practical applications, the number of continuous average filtering can be set according to requirements, which is not limited here.

Step S203: performing preset operations on the first image data and the second image data to obtain fingerprint image data;

Step S204: Generate a fingerprint image that can be used for matching and identification based on the fingerprint image data obtained through the final calculation.

In this embodiment, after the first image data and the second image data are acquired, a preset algorithm can be used to perform calculations on the acquired data to eliminate background noise, and further according to the calculated data in step S203 in step S203 In S204, high-quality fingerprint image data is generated, and a fingerprint image for subsequent fingerprint matching and identification is generated based on the fingerprint image data.

In some embodiments, as a possible implementation, in the embodiment of the present application, the fingerprint chip performs preset operations on the first image data and the second image data to obtain the fingerprint image data, which may include: The fingerprint image data is obtained by subtracting the pixel values of elements with the same number of rows and columns in the image data and the second image data. In some embodiments, the element img _ij = fliter_data1 _ij - fliter_data2 _ij or img _ij = fliter_data2 _ij - fliter_data1 _ij in the i-th row j column in the image matrix, wherein, fliter_data1 _ij is the i-th row in the first image data The element in column j, fliter_data2 _ij is the element in column j of row i in the second image data.

In some embodiments, as a possible implementation, in the embodiment of the present application, the fingerprint chip performs preset operations on the first image data and the second image data to obtain the fingerprint image data, which may include: The pixel values of elements with the same number of rows and columns in the image data and the second image data are subjected to a division operation to obtain fingerprint image data. In some embodiments, the element img _ij = fliter_data1 _ij / fliter_data2 _ij or img _ij = fliter_data2 _ij / fliter_data1 _ij in the i-th row j column in the image matrix, wherein, fliter_data1 _ij is the i-th row in the first image data The element value of column j, and fliter_data2 _ij is the element value of column j in row i in the second image data.

In the embodiment of the present application, after the fingerprint chip acquires the original fingerprint image data, it can continuously perform at least two average value filtering on the original fingerprint image data, and record the first image data obtained by the first average value filtering and the last average value filtering For the obtained second image data, a preset operation is finally performed on the first image data and the second image data to obtain fingerprint image data.

In order to further improve the quality of the fingerprint image, quantization processing and/or enhancement processing can also be performed on the fingerprint image data obtained through the preset calculation.

The data after the quantization processing and/or enhancement processing is used as the image data obtained by the final calculation, and based on this, a fingerprint image that can be used for matching and identification is generated.

Compared with related technologies, this application does not need to collect and store background data, which saves the cost of fingerprint image analysis, and does not need to rely on fixed background data to eliminate background noise, which improves the adaptability to application scenarios.

Referring to Fig. 3, another embodiment of a fingerprint image processing method in the embodiment of the present application may include:

Step S301: collect the original fingerprint image, and obtain the original fingerprint image data;

Step S302: Continuously perform at least two average value filters on the original fingerprint image data, and record the first image data obtained by the first average value filter and the second image data obtained by the last average value filter;

Step S303: performing preset operations on the first image data and the second image data to obtain fingerprint image data;

Step S304: Generate a fingerprint image that can be used for matching and identification based on the fingerprint image data obtained through the final calculation;

The content described in step S301 to step S304 in this embodiment is similar to the content described in step S201 to step S204 in the above embodiment shown in FIG. 2 , and will not be repeated here.

Step S305: Perform quantization processing and/or enhancement processing on the fingerprint image data.

In some embodiments, in order to further improve the quality of the fingerprint image, quantization processing and/or enhancement processing may be performed on the calculated data after step S303 in the above embodiment. The quantization processing includes one or more of linear quantization processing and histogram equalization processing; the enhancement processing includes one or more of Gaussian filtering processing, texture filtering processing, and gabor filtering processing.

The embodiment of the present application also provides a fingerprint chip, including:

The collection module is used to collect the original fingerprint image by using the optical fingerprint sensor, and obtain the original fingerprint image data;

A filtering module, configured to continuously perform at least two mean value filters on the original fingerprint image data, and record the first image data obtained by the first mean value filter and the second image data obtained by the last mean value filter;

The calculation module is used to perform preset calculations on the first image data and the second image data to obtain fingerprint image data that can be used for matching and identification, and generate fingerprint image data that can be used for matching and identification according to the fingerprint image data obtained through the final calculation. Recognized fingerprint image.

In some embodiments, as a possible implementation manner, in the embodiment of the present application, the computing module may include:

The first operation unit is used for subtracting the pixel values of elements with the same number of rows and columns in the first image data and the second image data to obtain fingerprint image data.

In some embodiments, as a possible implementation manner, in the embodiment of the present application, the computing module may include:

The second operation unit is used for performing division operation on the pixel values of elements with the same number of rows and columns in the first image data and the second image data to obtain fingerprint image data.

In some embodiments, as a possible implementation manner, the fingerprint chip in the embodiment of the present application may also include:

Supplementary computing module, used to perform quantization processing and/or enhancement processing on fingerprint image data; quantization processing includes one or more of linear quantization processing and histogram equalization processing; enhancement processing includes Gaussian filtering processing, texture filtering One or more of processing and Gabor filtering processing.

The data processed by the operation module is processed by the supplementary operation module, and the fingerprint data after the supplementary operation processing will be used as the data basis of the fingerprint generation module.

The present application provides an electronic device including the above-mentioned fingerprint chip. The electronic device can be used to implement the steps in the embodiment of the fingerprint image processing method shown in FIG. 2 or FIG. 3 , for example, steps S201 to S204 shown in FIG. 2 . Alternatively, when the processor executes the computer program, the functions of the modules or units in the above-mentioned device embodiments are realized. Those skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the above-described fingerprint chip, device and unit can refer to the corresponding process in the foregoing method embodiment, and will not be repeated here.

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still understand the foregoing The technical solutions described in each embodiment are modified, or some of the technical features are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the application.

S201: Collect an original fingerprint image, and acquire original fingerprint image data. S202: Continuously perform at least two mean value filtering on the original fingerprint image data, and record the first image data obtained by the first mean value filtering and the second image data obtained by the last mean value filter. S203: Perform preset operations on the first image data and the second image data to obtain fingerprint image data. S204: Generate a fingerprint image that can be used for matching and identification based on the fingerprint image data obtained through the final calculation. S301: Collect an original fingerprint image, and acquire original fingerprint image data. S302: Continuously perform at least two mean value filtering on the original fingerprint image data, and record the first image data obtained by the first mean value filtering and the second image data obtained by the last mean value filter. S303: Perform preset operations on the first image data and the second image data to obtain fingerprint image data. S304: Generate a fingerprint image that can be used for matching and identification based on the fingerprint image data obtained through the final calculation. S305: Perform quantization processing and/or enhancement processing on the fingerprint image data.

[ Fig. 1 ] is a schematic diagram of the effect of fingerprint image processing in the related art. [ Fig. 2 ] is a schematic diagram of an embodiment of a fingerprint image processing method in the embodiment of the present application. [ Fig. 3 ] is a schematic diagram of another embodiment of a fingerprint image processing method in the embodiment of the present application.

S201: collect the original fingerprint image, and obtain the original fingerprint image data

S202: Continuously perform at least two average value filtering on the original fingerprint image data, record the first image data obtained by the first average value filter and the second image data obtained by the last average value filter

S203: Perform preset calculations on the first image data and the second image data to obtain fingerprint image data

S204: Generate a fingerprint image that can be used for matching and identification based on the fingerprint image data obtained by the final calculation

Claims (12)

A fingerprint image processing method, matching and identifying a fingerprint image through a fingerprint chip, comprising: the fingerprint chip collects an original fingerprint image, and obtains an original fingerprint image data; The image data is continuously subjected to mean value filtering at least twice, and a first image data obtained by the first time mean value filtering and a second image data obtained by the last time mean value filtering are recorded; performing a preset operation on the data and the second image data to obtain a fingerprint image data; and the fingerprint chip generates a fingerprint image that can be used for matching and identification based on the fingerprint image data obtained through the final operation. The fingerprint image processing method according to claim 1, wherein performing preset operations on the first image data and the second image data to obtain the fingerprint image data includes: processing the first image The fingerprint image data is obtained by subtracting the pixel values of elements with the same number of rows and columns in the image data and the second image data. The fingerprint image processing method according to claim 1, wherein performing preset operations on the first image data and the second image data to obtain the fingerprint image data includes: processing the first image The fingerprint image data is obtained by performing a division operation on pixel values of elements having the same number of rows and columns in the image data and the second image data. The fingerprint image processing method according to any one of claims 1 to 3, further comprising: performing quantization processing or enhancement processing on the fingerprint image data obtained through preset calculations. The fingerprint image processing method according to any one of claims 1 to 3, further comprising: performing quantization processing and enhancement processing on the fingerprint image data obtained by preset calculations. The fingerprint image processing method as described in claim 4, wherein the quantization processing includes one or more of linear quantization processing and histogram equalization processing; the enhancement processing includes Gaussian filtering processing, texture filtering processing, and gabor filtering processing one or more of. A fingerprint chip, comprising: a collection module, which adopts an optical fingerprint sensor to collect an original fingerprint image, and obtains an original fingerprint image data; a filter module, which is used to continuously perform at least Two times of average filtering, recording a first image data obtained by the first average filtering and a second image data obtained by the last average filtering; The second image data is pre-calculated to obtain the calculated fingerprint image data; and a fingerprint generating module is used to generate a fingerprint image that can be used for matching and identification according to the image data obtained by the final calculation. The fingerprint chip as described in claim 7, wherein the computing module includes: a first computing unit, used to process pixels with the same number of rows and columns in the first image data and the second image data The value is subtracted to obtain the fingerprint image data. The fingerprint chip as described in claim 7, wherein the computing module includes: a second computing unit, used to process pixels with the same number of rows and columns in the first image data and the second image data The value is divided to obtain the fingerprint image data. The fingerprint chip as described in any one of claim items 7 to 9, which also includes: a supplementary computing module for performing quantization processing or enhancement processing on fingerprint image data; quantization processing includes linear quantization processing, histogram equalization One or more of the enhancement processing; the enhancement processing includes one or more of the Gaussian filtering processing, the texture filtering processing, and the Gabor filtering processing. The fingerprint chip as described in any one of claim items 7 to 9, which also includes: a supplementary computing module for performing quantization processing and enhancement processing on fingerprint image data; quantization processing includes linear quantization processing, histogram equalization One or more of the enhancement processing; the enhancement processing includes one or more of the Gaussian filtering processing, the texture filtering processing, and the Gabor filtering processing. An electronic device, the electronic device includes a fingerprint chip, and the fingerprint chip includes: a collection module, which uses an optical fingerprint sensor to collect an original fingerprint image, and obtains an original fingerprint image data; a filter module, which uses performing at least two mean value filters on the original fingerprint image data continuously, recording a first image data obtained by the first mean value filter and a second image data obtained by the last mean value filter; an operation module, It is used to perform preset calculations on the first image data and the second image data to obtain the calculated fingerprint image data; and a fingerprint generation module, which is used to generate the fingerprint image data according to the image data obtained by the final calculation. Fingerprint images that can be used for matching and identification.

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