CN115272451A - Light spot center positioning method and device - Google Patents

Abstract

The present invention provides a method and device for spot center positioning. The method includes: determining a first target area and a second target area of the spot image based on a grayscale histogram of the spot image; The first spot symmetry axis is determined in the first target area, and the second spot symmetry axis is determined in the second target area; the intersection of the first spot symmetry axis and the second spot symmetry axis is determined as the center of the spot Location. The light spot center positioning method and device provided by the present invention can not only improve the efficiency of light spot center positioning, but also improve the accuracy of light spot center positioning by introducing pixel correlation into the light spot center positioning.

Description

Spot center positioning method and device

technical field

The invention relates to the technical field of optical measurement, in particular to a spot center positioning method and device.

Background technique

Optical measurement is a high-tech measurement technology combining photoelectric technology and mechanical measurement. It can achieve fast and accurate measurement under the premise of borrowing computer technology. Therefore, optical measurement has become a more popular measurement method for modern industrial inspection.

Spot center positioning is crucial in optical measurement, which seriously affects the efficiency and accuracy of the entire measurement process. The current spot center positioning methods mainly include the center of gravity method, the Hough transform method and the Gaussian fitting method, but each of them has the following shortcomings: in the case of irregular shape of the spot and uneven gray distribution value, the positioning accuracy of the center of gravity method is poor; The Hough transform method needs to discretize the parameter space, which affects the actual detection accuracy of the algorithm; because the laser is only Gaussian in the fundamental mode, and the laser produced by many lasers is not a perfect Gaussian distribution during production, it is often deformed. At this time, using the Gaussian fitting method to locate the center of the spot will produce a large error and be time-consuming.

Therefore, how to improve the accuracy and efficiency of spot center positioning has become an urgent problem to be solved in the industry.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention provides a spot center positioning method and device.

In a first aspect, the present invention provides a spot center positioning method, including:

determining a first target area and a second target area of the spot image based on a grayscale histogram of the spot image;

determining a first spot symmetry axis in the first target area and determining a second spot symmetry axis in the second target area based on pixel correlation;

Determine the intersection of the first light spot symmetry axis and the second light spot symmetry axis as the center position of the light spot.

Optionally, according to a spot center positioning method provided in the present invention, based on pixel correlation, a first spot symmetry axis is determined in the first target area, and a second spot symmetry axis is determined in the second target area Axes, including:

determining a first subregion and a second subregion after the first target region is divided by any first dividing line, and obtaining a first pixel correlation between the first subregion and the second subregion;

Determining a first dividing line corresponding to a maximum first pixel correlation among all first pixel correlations as the first spot symmetry axis;

determining a third sub-region and a fourth sub-region after dividing the second target region by any second dividing line, and obtaining a second pixel correlation degree between the third sub-region and the fourth sub-region;

Determining a second dividing line corresponding to a maximum second pixel correlation among all second pixel correlations as the second light spot symmetry axis.

Optionally, according to a spot center positioning method provided in the present invention, determining the first target area and the second target area of the spot image based on a gray histogram of the spot image includes:

Determine the horizontal grayscale histogram and vertical grayscale histogram of the spot image respectively, the X coordinate of the horizontal grayscale histogram is the horizontal serial number of the pixel of the spot image, and the Y coordinate is each row of pixels of the spot image The total gray value, the X coordinate of the longitudinal gray histogram is the longitudinal serial number of the pixel in the spot image, and the Y coordinate is the total gray value of each row of pixels in the spot image;

The first target area is determined based on the horizontal grayscale histogram, and the second target area is determined based on the vertical grayscale histogram.

Optionally, according to a spot center positioning method provided by the present invention, the spot image is an annular spot image;

In the case where the spot image is an annular spot image, determining the first target area based on the horizontal grayscale histogram, and determining the second target area based on the vertical grayscale histogram include:

Based on the horizontal grayscale histogram, determine two first valley points closest to the maximum peak point of the horizontal grayscale histogram;

Determining the first target area based on X coordinates corresponding to the two first trough points respectively;

Based on the longitudinal grayscale histogram, determine two second valley points closest to the maximum peak point of the longitudinal grayscale histogram;

The second target area is determined based on X coordinates respectively corresponding to the two second valley points.

Optionally, according to a spot center positioning method provided by the present invention, the spot image is a non-ring spot image;

In the case where the spot image is a non-annular spot image, determining the first target area based on the horizontal grayscale histogram, and determining the second target area based on the vertical grayscale histogram, including :

In the horizontal grayscale histogram, determine the first target point and the second target point, the grayscale values corresponding to the first target point and the second target point respectively are the maximum peak points of the horizontal grayscale histogram The preset multiple of the corresponding gray value;

determining the first target area based on the X coordinate of the first target point and the X coordinate of the second target point;

In the vertical grayscale histogram, determine the third target point and the fourth target point, the grayscale values corresponding to the third target point and the fourth target point are the maximum peak points of the vertical grayscale histogram The preset multiple of the corresponding gray value;

The second target area is determined based on the X coordinate of the third target point and the X coordinate of the fourth target point.

Optionally, according to a spot center positioning method provided by the present invention, the preset multiple is 1/e, where e is a natural base number.

In the second aspect, the present invention also provides a spot center positioning device, including:

A first determining module, configured to determine a first target area and a second target area of the spot image based on a grayscale histogram of the spot image;

A second determining module, configured to determine a first light spot symmetry axis in the first target area based on pixel correlation, and determine a second light spot symmetry axis in the second target area;

The third determination module is configured to determine the intersection of the first light spot symmetry axis and the second light spot symmetry axis as the center position of the light spot.

In a third aspect, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and operable on the processor, and the processor implements the computer program described in the first aspect when executing the program. Spot center positioning method.

In a fourth aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the method for locating the center of the light spot as described in the first aspect is implemented.

In a fifth aspect, the present invention further provides a computer program product, including a computer program, and when the computer program is executed by a processor, the method for locating the center of the light spot as described in the first aspect is implemented.

The spot center positioning method and device provided by the present invention determine the first target area and the second target area of the spot image based on the gray histogram of the spot image, and then determine the first target area in the first target area based on the pixel correlation. Spot symmetry axis, determine the second spot symmetry axis in the second target area, and finally determine the intersection of the first spot symmetry axis and the second spot symmetry axis as the center position of the spot, which can not only improve the efficiency of spot center positioning, but also pass Introducing pixel correlation into spot center location can improve the accuracy of spot center location.

Description of drawings

In order to more clearly illustrate the present invention or the technical solutions in the prior art, the accompanying drawings that need to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings in the following description are the present invention. For some embodiments of the invention, those skilled in the art can also obtain other drawings based on these drawings without creative effort.

Fig. 1 is one of the schematic flow charts of the spot center positioning method provided by the present invention;

Fig. 2 is the second schematic flow diagram of the spot center positioning method provided by the present invention;

Fig. 3 is a schematic diagram of an annular spot image provided by the present invention;

Fig. 4 is a schematic diagram of the longitudinal grayscale histogram of the annular spot image provided by the present invention;

Fig. 5 is a schematic diagram of the horizontal grayscale histogram of the annular spot image provided by the present invention;

Fig. 6 is a schematic diagram of a speckle image provided by the present invention;

Fig. 7 is a schematic diagram of a longitudinal grayscale histogram of a speckle image provided by the present invention;

Fig. 8 is a schematic diagram of a horizontal grayscale histogram of a speckle image provided by the present invention;

Fig. 9 is a schematic structural view of the spot center positioning device provided by the present invention;

Fig. 10 is a schematic diagram of the physical structure of the electronic device provided by the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention , but not all examples. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

In order to facilitate a clearer understanding of the various embodiments of the present invention, some relevant background knowledge is introduced as follows.

The current spot center positioning methods include gravity center method, Hough transform method and Gaussian fitting method, etc., but each of these methods has the following shortcomings: in the case of irregular shape of the spot and uneven gray distribution value, the positioning accuracy of the center of gravity method is poor ; The Hough transform method needs to discretize the parameter space, which affects the actual detection accuracy of the algorithm; because the laser is only Gaussian in the fundamental mode, and the laser produced by many lasers is not a perfect Gaussian distribution, often some At this time, using the Gaussian fitting method to locate the center of the spot will produce a large error, and it is time-consuming. It is generally used in the process of preprocessing the image data after the image data is collected.

The existing spot center positioning methods mainly have the following defects:

(1) The positioning of the center of the spot is not accurate, so that it is impossible to accurately crop the partial image containing more feature data in the entire image.

(2) For the spot with irregular shape, the algorithm of directly using the histogram to determine the center of the spot has the defects that the center is difficult to locate and the positioning error is large.

(3) The current spot center positioning algorithm with high positioning accuracy is not suitable for application in the process of image data acquisition due to the large amount of calculation. .

In order to overcome the above-mentioned defects, the present invention provides a spot center positioning method and device. The spot center positioning method and device provided by the present invention will be described below with reference to FIGS. 1-10 .

Fig. 1 is one of the schematic flow charts of the spot center positioning method provided by the present invention, as shown in Fig. 1, the method includes:

Step 100, based on the grayscale histogram of the spot image, determine a first target area and a second target area of the spot image.

Specifically, a grayscale histogram of the spot image may be acquired, and a first target area and a second target area of the spot image may be determined based on the gray histogram of the spot image.

Optionally, the first target area and the second target area of the spot image may be substantially effective areas of the spot in the entire spot image.

Step 110, based on pixel correlation, determine a first light spot symmetry axis in the first target area, and determine a second light spot symmetry axis in the second target area.

Specifically, after the first target area and the second target area of the spot image are determined, the first spot symmetry axis can be determined in the first target area and the second spot can be determined in the second target area based on pixel correlation Symmetry axis.

It can be understood that, based on the pixel correlation, two symmetry axes of the light spot can be determined in the determined target area.

Step 120, determining the intersection of the first light spot symmetry axis and the second light spot symmetry axis as the center position of the light spot.

Specifically, after determining the first spot symmetry axis and the second spot symmetry axis of the light spot based on the pixel correlation, the intersection point of the first light spot symmetry axis and the second light spot symmetry axis can be determined, and the intersection point can be used as the central position of the light spot .

In order to overcome the defects of low positioning accuracy and low positioning efficiency of the existing spot center positioning method, the present invention determines the first target area and the second target area of the spot image based on the gray histogram of the spot image, and then based on the pixel correlation property, determine the first spot symmetry axis in the first target area, determine the second light spot symmetry axis in the second target area, and finally determine the intersection of the first light spot symmetry axis and the second light spot symmetry axis as the center position of the light spot, Not only can the efficiency of spot centering be improved, but also the accuracy of spot centering can be improved by introducing pixel correlation into spot centering.

The spot center positioning method provided by the present invention determines the first target area and the second target area of the spot image based on the gray histogram of the spot image, and then determines the symmetry of the first spot in the first target area based on the pixel correlation. Axis, determine the second spot symmetry axis in the second target area, and finally determine the intersection point of the first spot symmetry axis and the second spot symmetry axis as the center position of the spot, not only can improve the efficiency of spot center positioning, but also through the pixel Correlation is introduced into spot center positioning, which can improve the accuracy of spot center positioning.

Optionally, based on pixel correlation, determining a first light spot symmetry axis in the first target area, and determining a second light spot symmetry axis in the second target area includes:

determining a first subregion and a second subregion after the first target region is divided by any first dividing line, and obtaining a first pixel correlation between the first subregion and the second subregion;

Determining a first dividing line corresponding to a maximum first pixel correlation among all first pixel correlations as the first spot symmetry axis;

determining a third sub-region and a fourth sub-region after dividing the second target region by any second dividing line, and obtaining a second pixel correlation degree between the third sub-region and the fourth sub-region;

Determining a second dividing line corresponding to a maximum second pixel correlation among all second pixel correlations as the second light spot symmetry axis.

Specifically, the first sub-region and the second sub-region after the first target region is divided by any first dividing line may be determined, and the first pixel correlation between the first sub-region and the second sub-region is obtained; and The first division line corresponding to the maximum first pixel correlation among all the first pixel correlations is determined as the first light spot symmetry axis.

Optionally, any first dividing line can be used to move every integer pixel within the range of the first target area, and the first pixels of the first sub-area and the second sub-area divided by the first dividing line can be obtained relativity.

Optionally, the first dividing line corresponding to the largest first pixel correlation among all the acquired first pixel correlations may be used as the first light spot symmetry axis.

Optionally, when obtaining the first pixel correlation degree between the first sub-region and the second sub-region, the smaller region in the first sub-region and the second sub-region can be used as a reference first, and the first dividing line is Symmetry axis, crop the larger area in the first sub-area and the second sub-area so that the two areas have the same size and are symmetrical about the first dividing line, and then determine the first pixel of the first sub-area and the second sub-area relativity.

Specifically, the third sub-region and the fourth sub-region after the second target region is divided by any second dividing line may be determined, and the second pixel correlation between the third sub-region and the fourth sub-region is obtained; and Determine the second dividing line corresponding to the maximum second pixel correlation among all the second pixel correlations as the second light spot symmetry axis.

Optionally, any second dividing line can be used to move every integer pixel within the range of the second target area, and obtain the second pixels of the third sub-area and the fourth sub-area divided by the second dividing line relativity.

Optionally, a second dividing line corresponding to a maximum second pixel correlation among all acquired second pixel correlations may be used as a second light spot symmetry axis.

Optionally, when acquiring the second pixel correlation between the third sub-region and the fourth sub-region, the smaller region in the third sub-region and the fourth sub-region can be used as a reference first, and the second dividing line is Axis of symmetry, crop the larger area in the third sub-area and the fourth sub-area so that the size of the two areas is the same and symmetrical about the second dividing line, and then determine the second pixel of the third sub-area and the fourth sub-area relativity.

Optionally, the first pixel correlation degree between the first sub-region and the second sub-region, and the second pixel correlation degree between the third sub-region and the fourth sub-region can be obtained based on any function for calculating the correlation degree, for example, the correlation The coefficient function corr is not specifically limited in the present invention.

The present invention introduces pixel correlation into spot center positioning, determines the symmetry axis of the spot based on the correlation of pixels, and then determines the center position of the spot based on the symmetry axis of the spot, which can not only improve the accuracy of spot center positioning, but also reduce the algorithm Run time, improve the efficiency of spot center positioning.

Optionally, based on the grayscale histogram of the spot image, determining the first target area and the second target area of the spot image includes:

Determine the horizontal grayscale histogram and vertical grayscale histogram of the spot image respectively, the X coordinate of the horizontal grayscale histogram is the horizontal serial number of the pixel of the spot image, and the Y coordinate is each row of pixels of the spot image The total gray value, the X coordinate of the longitudinal gray histogram is the longitudinal serial number of the pixel in the spot image, and the Y coordinate is the total gray value of each row of pixels in the spot image;

The first target area is determined based on the horizontal grayscale histogram, and the second target area is determined based on the vertical grayscale histogram.

Specifically, the horizontal grayscale histogram and vertical grayscale histogram of the spot image can be determined first, then the first target area of the spot image can be determined based on the horizontal grayscale histogram, and the second target area of the spot image can be determined based on the vertical grayscale histogram. target area.

Among them, the X coordinate of the horizontal grayscale histogram is the horizontal serial number of the spot image pixel, the Y coordinate is the total grayscale value of each row of pixels in the spot image, and the X coordinate of the vertical grayscale histogram is the vertical sequence of the spot image pixel No., and the Y coordinate is the total gray value of each row of pixels in the spot image.

It can be understood that the X coordinate of the horizontal grayscale histogram is the row sequence number of each row of pixels of the spot image, and the Y coordinate is the total gray value of each row of pixels of the spot image. For example, the pixels of the spot image have N row, the horizontal grayscale histogram represents a histogram sequence of N values.

It can be understood that the X coordinate of the vertical grayscale histogram is the column serial number of each column of pixels in the spot image, and the Y coordinate is the total gray value of each column of pixels in the spot image. For example, the pixels of the spot image have M column, the longitudinal gray histogram represents a histogram sequence of M values.

Optionally, the spot image is an annular spot image;

In the case where the spot image is an annular spot image, determining the first target area based on the horizontal grayscale histogram, and determining the second target area based on the vertical grayscale histogram include:

Based on the horizontal grayscale histogram, determine two first valley points closest to the maximum peak point of the horizontal grayscale histogram;

Determining the first target area based on X coordinates corresponding to the two first trough points respectively;

Based on the longitudinal grayscale histogram, determine two second valley points closest to the maximum peak point of the longitudinal grayscale histogram;

The second target area is determined based on X coordinates respectively corresponding to the two second valley points.

Optionally, in this embodiment of the present invention, the spot image may be an annular spot image, that is, a spot image with a ring-shaped structured spot.

Specifically, when the spot image is an annular spot image, the two first valley points closest to the maximum peak point of the horizontal grayscale histogram can be determined first based on the horizontal grayscale histogram, and then based on the two first valley points The X coordinates corresponding to the points respectively determine the first target area.

Specifically, when the spot image is an annular spot image, the two second valley points nearest to the maximum peak point of the longitudinal grayscale histogram can be determined first based on the longitudinal grayscale histogram, and then based on the two second valley points The X coordinates corresponding to the points determine the second target area.

Optionally, the spot image is a non-annular spot image;

In the case where the spot image is a non-annular spot image, determining the first target area based on the horizontal grayscale histogram, and determining the second target area based on the vertical grayscale histogram, including :

In the horizontal grayscale histogram, determine the first target point and the second target point, the grayscale values corresponding to the first target point and the second target point respectively are the maximum peak points of the horizontal grayscale histogram The preset multiple of the corresponding gray value;

determining the first target area based on the X coordinate of the first target point and the X coordinate of the second target point;

In the vertical grayscale histogram, determine the third target point and the fourth target point, the grayscale values corresponding to the third target point and the fourth target point are the maximum peak points of the vertical grayscale histogram The preset multiple of the corresponding gray value;

The second target area is determined based on the X coordinate of the third target point and the X coordinate of the fourth target point.

Optionally, in this embodiment of the present invention, the spot image may be a non-ring spot image, that is, a spot image without a ring-shaped structured spot.

Specifically, in the case that the spot image is a non-circular spot image, the first target point and the second target point can be determined first in the horizontal grayscale histogram, wherein the grayscales corresponding to the first target point and the second target point respectively The value is a preset multiple of the grayscale value corresponding to the maximum peak point of the horizontal grayscale histogram, and then the first target area is determined based on the X coordinate of the first target point and the X coordinate of the second target point.

Specifically, in the case that the spot image is a non-ring spot image, the third target point and the fourth target point can be determined first in the longitudinal grayscale histogram, where the grayscales of the third target point and the fourth target point respectively correspond to The value is a preset multiple of the grayscale value corresponding to the maximum peak point of the vertical grayscale histogram, and then the second target area is determined based on the X coordinate of the third target point and the X coordinate of the fourth target point.

Optionally, in this embodiment of the present invention, the grayscale values corresponding to the first target point and the second target point may be 1/e of the grayscale value corresponding to the maximum peak point of the horizontal grayscale histogram, where e is the natural base.

Optionally, in this embodiment of the present invention, the grayscale values corresponding to the third target point and the fourth target point may be 1/e of the grayscale value corresponding to the maximum peak point of the longitudinal grayscale histogram, where e is the natural base.

Fig. 2 is the second schematic flow diagram of the spot center positioning method provided by the present invention. As shown in Fig. 2, it mainly includes the process of determining the symmetry axis of the spot, specifically including the following steps 200-step 230:

Step 200, calculating the grayscale histogram of the spot image.

Optionally, a grayscale histogram in the Y direction and a grayscale histogram in the X direction of the spot image may be calculated, that is, a horizontal grayscale histogram and a vertical grayscale histogram of the spot image.

Step 210, determine the area where the symmetry axis of the light spot is located according to the grayscale histogram.

Fig. 3 is a schematic diagram of an annular spot image provided by the present invention, Fig. 4 is a schematic diagram of a longitudinal grayscale histogram of an annular spot image provided by the present invention, and Fig. 5 is a schematic diagram of a horizontal grayscale histogram of an annular spot image provided by the present invention, As shown in Figure 3 to Figure 5, for a spot image with a ring structure, the range m of the area where the spot symmetry axis is located is: between the two valley points closest to the maximum peak point of the histogram, that is, the spot symmetry axis can be from Move from the start end of m to the end end.

Optionally, the two minimum values that are closest to the maximum peak point of the histogram can be obtained through the derivation method in mathematics, that is, the two valley points closest to the maximum peak point of the histogram can be obtained.

In step 220, any dividing line is moved in the area where the symmetry axis of the light spot is located, and the correlation calculation is performed on the areas on both sides of the dividing line based on the small areas on both sides of the dividing line.

It is understandable that, since the size requirements of the two areas for calculating the correlation are the same, it is possible to use the smaller areas on both sides of the dividing line as a benchmark, and crop the larger areas on both sides of the dividing line to make it correspond to the smaller The sizes of the regions are the same, and after cropping, the two regions are symmetrical about the dividing line.

Step 230, when the degree of correlation is maximum, determine that the position of the dividing line is the position of the symmetry axis of the light spot.

Optionally, it can be determined that any one of the first dividing lines moves from the beginning to the end of m shown in FIG. When the correlation degree of the regions on both sides of the first dividing line is the largest, it can be determined that the position of the first dividing line at this time is the position of the symmetry axis of the first light spot.

Optionally, it can be determined that any second dividing line moves from the beginning to the end of m shown in FIG. When the correlation degree of the regions on both sides of the second dividing line is the largest, it can be determined that the position of the second dividing line at this time is the position of the symmetry axis of the second light spot.

Optionally, the above-mentioned steps 200 to 230 can be performed once in the left-right direction and the up-down direction of the two-dimensional spot image, and then two spot symmetry axes can be obtained, and the intersection point of the two spot symmetry axes can be determined as the spot Central location.

Optionally, in the embodiment of the present invention, the sliding area of the symmetry axis of the spot can be determined first through the gray histogram of the spot image, and then the correlation calculation is performed on the images on the left and right sides of the symmetry axis by sliding the symmetry axis, and the correlation The axis of symmetry with the largest degree is the axis of symmetry of the spot. By this method, two axes of symmetry of the spot are determined in the horizontal and vertical directions of the two-dimensional spot image, and the intersection point is the center of the spot.

The light spot center positioning method provided by the embodiment of the present invention introduces correlation into the light spot center positioning, so that the center of the irregular circular light spot can be positioned more accurately.

Optionally, the spot center positioning method provided in the embodiment of the present invention is not limited to the spot center positioning, and can also be applied to other center positioning scenarios of images with symmetrical characteristics. The speckle image is taken as an example for description below.

Fig. 6 is a schematic diagram of a speckle image provided by the present invention, Fig. 7 is a schematic diagram of a longitudinal grayscale histogram of a speckle image provided by the present invention, and Fig. 8 is a schematic diagram of a horizontal grayscale histogram of a speckle image provided by the present invention, As shown in Figures 6 to 8, the symmetry axis of the speckle can still be determined based on the above steps 200 to 230, and then the center position of the speckle can be determined. For the speckle image, the beginning and end of the range m where the symmetry axis is located correspond to The grayscale value of is the preset multiple of the grayscale value corresponding to the maximum peak point of the horizontal grayscale histogram or the maximum peak point of the vertical grayscale histogram. For example, the preset multiple can be 1/e, where e is natural Base number.

Optionally, the method for locating the center of the light spot provided in the embodiment of the present invention may be applied in the process of collecting image data to improve the positioning accuracy of the center of the light spot.

It can be understood that, in continuous photometric images, the position of the light spot in the whole image is almost unchanged.

Therefore, in the embodiment of the present invention, only the central position of part of the spot images in the continuous photometric images can be determined, or the central position of the spot can be determined every preset number of images, for example, the spot can be determined once every 10 images Central location.

Optionally, in the case where the positioning accuracy of the spot center position needs to be accurate to sub-pixels, after obtaining the spot center position of integer bit pixels based on the spot center positioning method described above, based on the spot center position and the similarity coefficient Fitting method, the center position of the spot is accurate to sub-pixel.

Specifically, based on the coordinates of the spot center position of the integer bit pixel and the pixel position coordinates of the surrounding eight neighborhoods of the spot center position of the integer bit pixel, the quadratic surface expression F(x, y)=a ₁ x ² + a ₂ y ² +a ₃ x+a ₄ y+a ₅ xy+a ₆ , determine the spot center position of the sub-pixel, where a ₁ , a ₂ , a ₃ , a ₄ , a ₅ and a ₆ are coefficients, x, y are pixel position coordinates.

Specifically, the spot center position coordinates of integer-bit pixels and the pixel position coordinates of the surrounding eight neighborhoods can be substituted into the above-mentioned quadratic surface expression respectively, and the overdetermined equation is solved to obtain the size of each coefficient of the quadratic surface expression, Afterwards, the derivative of the quadratic surface expression is calculated to calculate the minimum value, and the coordinate corresponding to the minimum value is the center position of the sub-pixel spot.

The spot center positioning method provided by the present invention determines the first target area and the second target area of the spot image based on the gray histogram of the spot image, and then determines the symmetry of the first spot in the first target area based on the pixel correlation. Axis, determine the second spot symmetry axis in the second target area, and finally determine the intersection point of the first spot symmetry axis and the second spot symmetry axis as the center position of the spot, not only can improve the efficiency of spot center positioning, but also through the pixel Correlation is introduced into spot center positioning, which can improve the accuracy of spot center positioning.

The spot center positioning device provided by the present invention is described below, and the spot center positioning device described below and the spot center positioning method described above can be referred to in correspondence.

Fig. 9 is a schematic structural diagram of a spot center positioning device provided by the present invention. As shown in Fig. 9, the device includes: a first determining module 910, a second determining module 920 and a third determining module 930; wherein:

The first determining module 910 is configured to determine the first target area and the second target area of the spot image based on the gray histogram of the spot image;

The second determination module 920 is configured to determine a first light spot symmetry axis in the first target area based on pixel correlation, and determine a second light spot symmetry axis in the second target area;

The third determination module 930 is configured to determine the intersection of the first light spot symmetry axis and the second light spot symmetry axis as the center position of the light spot.

Specifically, the spot center positioning device provided by the embodiment of the present invention can determine the first target area and the second target area of the spot image based on the gray histogram of the spot image through the first determining module 910; 920 Based on the pixel correlation, determine the first light spot symmetry axis in the first target area, and determine the second light spot symmetry axis in the second target area; finally determine the first light spot symmetry axis and the second light spot symmetry axis through the third determination module 930 The intersection point of the symmetry axis is the center position of the spot.

The spot center positioning device provided by the present invention determines the first target area and the second target area of the spot image based on the gray histogram of the spot image, and then determines the symmetry of the first spot in the first target area based on the pixel correlation. Axis, determine the second spot symmetry axis in the second target area, and finally determine the intersection point of the first spot symmetry axis and the second spot symmetry axis as the center position of the spot, not only can improve the efficiency of spot center positioning, but also through the pixel Correlation is introduced into spot center positioning, which can improve the accuracy of spot center positioning.

What needs to be explained here is that the above-mentioned device provided by the embodiment of the present invention can realize all the method steps realized by the above-mentioned light spot center positioning method embodiment, and can achieve the same technical effect. The same parts and beneficial effects of the embodiments are described in detail.

Fig. 10 is a schematic diagram of the physical structure of the electronic device provided by the present invention. As shown in Fig. 10, the electronic device may include: a processor (processor) 1010, a communication interface (Communications Interface) 1020, a memory (memory) 1030 and a communication bus 1040 , wherein, the processor 1010 , the communication interface 1020 , and the memory 1030 communicate with each other through the communication bus 1040 . The processor 1010 can call the logic instructions in the memory 1030 to execute the method for locating the center of the light spot provided by the above-mentioned methods, and the method includes:

determining a first target area and a second target area of the spot image based on a grayscale histogram of the spot image;

determining a first spot symmetry axis in the first target area and determining a second spot symmetry axis in the second target area based on pixel correlation;

Determine the intersection of the first light spot symmetry axis and the second light spot symmetry axis as the center position of the light spot.

In addition, the above-mentioned logic instructions in the memory 1030 may be implemented in the form of software functional units and be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the essence of the technical solution of the present invention or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including Several instructions are used to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk and other media that can store program codes. .

On the other hand, the present invention also provides a computer program product, the computer program product includes a computer program stored on a non-transitory computer-readable storage medium, the computer program includes program instructions, and when the program instructions are executed by a computer During execution, the computer can execute the spot center positioning method provided by the above-mentioned methods, and the method includes:

determining a first target area and a second target area of the spot image based on a grayscale histogram of the spot image;

determining a first spot symmetry axis in the first target area and determining a second spot symmetry axis in the second target area based on pixel correlation;

Determine the intersection of the first light spot symmetry axis and the second light spot symmetry axis as the center position of the light spot.

In yet another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it is implemented to perform the methods for locating the center of the light spot provided above, the method comprising:

determining a first target area and a second target area of the spot image based on a grayscale histogram of the spot image;

determining a first spot symmetry axis in the first target area and determining a second spot symmetry axis in the second target area based on pixel correlation;

Determine the intersection of the first light spot symmetry axis and the second light spot symmetry axis as the center position of the light spot.

The device embodiments described above are only illustrative, and the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in One place, or it can be distributed to multiple network elements. Part or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. It can be understood and implemented by those skilled in the art without any creative efforts.

Through the above description of the implementations, those skilled in the art can clearly understand that each implementation can be implemented by means of software plus a necessary general hardware platform, and of course also by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the prior art can be embodied in the form of software products, and the computer software products can be stored in computer-readable storage media, such as ROM/RAM, magnetic discs, optical discs, etc., including several instructions to make a computer device (which may be a personal computer, server, or network device, etc.) execute the methods described in various embodiments or some parts of the embodiments.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; 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 present invention.

Claims (10)

1. A spot center location method, is characterized in that, comprises: determining a first target area and a second target area of the spot image based on a grayscale histogram of the spot image; determining a first spot symmetry axis in the first target area and determining a second spot symmetry axis in the second target area based on pixel correlation; Determine the intersection of the first light spot symmetry axis and the second light spot symmetry axis as the center position of the light spot. 2. The spot center positioning method according to claim 1, characterized in that, based on pixel correlation, the first spot symmetry axis is determined in the first target area, and the second spot axis is determined in the second target area. The axis of symmetry of the spot, including: determining a first subregion and a second subregion after the first target region is divided by any first dividing line, and obtaining a first pixel correlation between the first subregion and the second subregion; Determining a first dividing line corresponding to a maximum first pixel correlation among all first pixel correlations as the first spot symmetry axis; determining a third sub-region and a fourth sub-region after dividing the second target region by any second dividing line, and obtaining a second pixel correlation degree between the third sub-region and the fourth sub-region; Determining a second dividing line corresponding to a maximum second pixel correlation among all second pixel correlations as the second light spot symmetry axis. 3. The spot center positioning method according to claim 1 or 2, wherein, based on the grayscale histogram of the spot image, determining the first target area and the second target area of the spot image comprises: Determine the horizontal grayscale histogram and vertical grayscale histogram of the spot image respectively, the X coordinate of the horizontal grayscale histogram is the horizontal serial number of the pixel of the spot image, and the Y coordinate is each row of pixels of the spot image The total gray value, the X coordinate of the longitudinal gray histogram is the longitudinal serial number of the pixel in the spot image, and the Y coordinate is the total gray value of each row of pixels in the spot image; The first target area is determined based on the horizontal grayscale histogram, and the second target area is determined based on the vertical grayscale histogram. 4. The spot center positioning method according to claim 3, wherein the spot image is an annular spot image; In the case where the spot image is an annular spot image, determining the first target area based on the horizontal grayscale histogram, and determining the second target area based on the vertical grayscale histogram include: Based on the horizontal grayscale histogram, determine two first valley points closest to the maximum peak point of the horizontal grayscale histogram; Determining the first target area based on X coordinates corresponding to the two first trough points respectively; Based on the longitudinal grayscale histogram, determine two second valley points closest to the maximum peak point of the longitudinal grayscale histogram; The second target area is determined based on X coordinates respectively corresponding to the two second valley points. 5. The spot center positioning method according to claim 3, wherein the spot image is a non-ring spot image; In the case where the spot image is a non-annular spot image, determining the first target area based on the horizontal grayscale histogram, and determining the second target area based on the vertical grayscale histogram, including : In the horizontal grayscale histogram, determine the first target point and the second target point, the grayscale values corresponding to the first target point and the second target point respectively are the maximum peak points of the horizontal grayscale histogram The preset multiple of the corresponding gray value; determining the first target area based on the X coordinate of the first target point and the X coordinate of the second target point; In the vertical grayscale histogram, determine the third target point and the fourth target point, the grayscale values corresponding to the third target point and the fourth target point are the maximum peak points of the vertical grayscale histogram The preset multiple of the corresponding gray value; The second target area is determined based on the X coordinate of the third target point and the X coordinate of the fourth target point. 6. The spot center positioning method according to claim 5, wherein the preset multiple is 1/e, wherein e is a natural base. 7. A spot center positioning device, characterized in that it comprises: A first determining module, configured to determine a first target area and a second target area of the spot image based on a grayscale histogram of the spot image; A second determining module, configured to determine a first light spot symmetry axis in the first target area based on pixel correlation, and determine a second light spot symmetry axis in the second target area; The third determination module is configured to determine the intersection of the first light spot symmetry axis and the second light spot symmetry axis as the center position of the light spot. 8. An electronic device comprising a memory, a processor, and a computer program stored on the memory and operable on the processor, wherein the processor according to claim 1 is implemented when executing the program. The spot center positioning method described in any one of to 6. 9. A non-transitory computer-readable storage medium, on which a computer program is stored, wherein when the computer program is executed by a processor, the spot center positioning method according to any one of claims 1 to 6 is implemented. 10. A computer program product, comprising a computer program, characterized in that, when the computer program is executed by a processor, the spot center positioning method according to any one of claims 1 to 6 is implemented.

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