WO2023070862A1

WO2023070862A1 - Method and apparatus for correcting image distortion of wide-angle lens, and photographing device

Info

Publication number: WO2023070862A1
Application number: PCT/CN2021/137562
Authority: WO
Inventors: 王辉
Original assignee: 上海闻泰信息技术有限公司
Priority date: 2021-10-25
Filing date: 2021-12-13
Publication date: 2023-05-04
Also published as: CN113962892A

Abstract

A method and apparatus for correcting image distortion of a wide-angle lens, and a photographing device. The method comprises: inputting an original distorted image and a preset first calibration image (S1); determining a second calibration image according to the original distorted image and the first calibration image (S2); calculating, according to distortion parameters of the first calibration image and a distortion mathematical model, distorted image coordinates corresponding to the second calibration image (S3); determining difference parameters of the second calibration image, and correcting the distorted image coordinates according to the difference parameters (S4); and outputting a corrected image according to pixel values corresponding to the corrected distorted image coordinates (S5). According to the method, there is no need to calibrate a plurality of sets of distortion parameters, and correction of an original wide-angle distorted image of any resolution can be achieved only by calculating one set of distortion parameters corresponding to an image having the maximum resolution, thereby greatly simplifying the correction process, simultaneously avoiding the situation that calibrated distortion parameters have a large error when a small-resolution image is used for calibration, and thus improving correction accuracy.

Description

Method and device for correcting wide-angle lens image distortion and photographic equipment

This disclosure claims the priority of the Chinese patent application with the application number 202111239136.4 and the title of the invention "Method, device and photographic equipment for correcting wide-angle lens image distortion" submitted to the China Patent Office on October 25, 2021, the entire contents of which are incorporated by reference in this disclosure.

technical field

The present disclosure relates to a method, device and camera equipment for correcting image distortion of a wide-angle lens.

Background technique

At present, the correction technology of wide-angle lens image distortion generally uses the checkerboard image to calculate the distortion parameters conforming to the distortion mathematical model, and then performs coordinate transformation on the distorted image through the distortion parameters and the distortion mathematical model to achieve the purpose of correction. However, when the same camera shoots images with different resolutions, due to errors in the distortion parameters calculated from images with different resolutions, it will directly use the distortion parameters calculated from the previous resolutions to process images of different resolutions captured by the same model of camera lens. During distortion correction, correction abnormality occurs.

In the related art, when the resolutions of the images captured by the wide-angle camera are relatively large, multiple sets of distortion parameters need to be calibrated for the images of multiple resolutions, so that when correcting the captured images, the resolution of the captured images is selected according to the resolution of the captured images. The distortion parameters corresponding to the resolution are used to correct the captured image. Therefore, when the resolution of the image is large, it is necessary to calibrate many sets of distortion parameters correspondingly, which makes the current correction method very cumbersome, and when calibrating an image with a small resolution, the calculated distortion parameter error is relatively large, resulting in the correction The image of is abnormal. In addition, most of the current cameras support digital zoom technology, but the digital zoom of the wide-angle lens will also cause abnormalities in the correction of distorted images. However, most of the current cameras do not support the function of correcting the images captured after digital zoom.

Contents of the invention

(1) Technical problems to be solved

How to implement the correction of the original wide-angle distorted image of arbitrary resolution.

(2) Technical solutions

According to various embodiments of the present disclosure, a method, an apparatus, and a photographing apparatus for correcting image distortion of a wide-angle lens are provided.

A method for correcting image distortion of a wide-angle lens, the method comprising:

Input the original distorted image and the preset first calibration image;

determining a second calibration image based on the original distorted image and the first calibration image;

calculating the distorted image coordinates corresponding to the second calibration image according to the distortion parameters of the first calibration image and the distortion mathematical model;

determining a difference parameter of the second calibration image, and correcting the distorted image coordinates according to the difference parameter;

Output the corrected image according to the pixel values corresponding to the corrected distorted image coordinates.

In addition, the method for correcting image distortion of a wide-angle lens according to an embodiment of the present disclosure may also have the following additional technical features:

Further, determining the second calibration image according to the original distorted image and the first calibration image includes: determining a maximum resolution under the resolution of the first calibration image that is the same as the aspect ratio of the original distorted image The image corresponding to the rate is used as the second calibration image.

Further, the difference parameters include: a size ratio coefficient between the second calibration image and the original distorted image, and an edge size difference between the first calibration image and the second calibration image.

Further, determining the difference parameter of the second calibration image includes: determining the resolution ratio of the second calibration image to the original distorted image as the size scale factor; determining the ratio of the first calibration image to the The difference between the number of pixels in the horizontal direction and the vertical direction of the second calibration image is the difference in edge size.

Further, determining the difference parameter of the second calibration image includes: determining a resolution ratio of the second calibration image to the original distorted image, and using the ratio of the resolution ratio to the digital zoom factor of the wide-angle lens as the ratio The size ratio factor; determine the first ratio of the number of pixels in the horizontal direction of the second calibration image to the digital zoom factor, and determine the number of pixels in the horizontal direction of the second calibration image and the first ratio Determine the first difference between the number of pixels in the horizontal direction of the first calibration image and the second calibration image; and determine the difference between the number of pixels in the vertical direction of the second calibration image and The second ratio of the digital zoom factor determines the third difference between the number of pixels in the vertical direction of the second calibration image and the second ratio, and determines the first calibration image and the second calibration image The fourth difference in the number of pixels in the vertical direction; determine the sum of the first difference and the second difference, and the sum of the third difference and the fourth difference as the edge Size difference.

Further, correcting the distorted image coordinates according to the difference parameter includes: translating the distorted image coordinates according to the edge size difference; scaling the translated distorted image coordinates according to the size ratio coefficient .

Further, calculating the distorted image coordinates corresponding to the second calibration image according to the distortion parameters of the first calibration image and the distortion mathematical model includes:

Calculate the distorted image coordinates corresponding to each pixel in the second calibration image according to the distortion parameters of the first calibration image and the distortion mathematical model.

Further, calculating the distorted image coordinates corresponding to the second calibration image according to the distortion parameters of the first calibration image and the distortion mathematical model further includes:

According to the distortion parameters and the distortion mathematical model of the first calibration image, pixel points are taken out according to preset intervals, and the coordinates of the distorted image corresponding to the pixel points are calculated;

Estimating the distorted image coordinates corresponding to other points between adjacent points of the pixel point according to an interpolation method.

Further, output the corrected image according to the pixel value corresponding to the corrected distorted image coordinates, including:

Rounding the pixel value corresponding to the corrected distorted image coordinates to obtain the corrected image;

The corrected image is output.

Further, the translation of the distorted image coordinates according to the edge size difference includes:

Taking the distance translated in the lateral direction by the distorted image coordinates corresponding to the second calibration image as the lateral size difference;

The distance that the distorted image coordinates corresponding to the second calibration image are translated in the vertical direction is taken as the size difference in the vertical direction.

A device for correcting image distortion of a wide-angle lens, the device comprising:

The input module is configured to input the original distorted image and the preset first calibration image;

A determining module configured to determine a second calibration image according to the original distorted image and the first calibration image;

A calculation module configured to calculate the distorted image coordinates corresponding to the second calibration image according to the distortion parameters of the first calibration image and the distortion mathematical model;

A correction module configured to determine a difference parameter of the second calibration image, and correct the coordinates of the distorted image according to the difference parameter;

The output module is configured to output the corrected image according to the pixel values corresponding to the corrected distorted image coordinates.

As an optional implementation manner of the embodiment of the present disclosure, the determining module is specifically configured to: determine the maximum resolution below the resolution of the first calibration image corresponding to the aspect ratio of the original distorted image image, as the second calibration image.

As an optional implementation manner of the embodiment of the present disclosure, the difference parameter includes: the size ratio coefficient between the second calibration image and the original distorted image, and the first calibration image and the second calibration image The edge size difference of the image.

As an optional implementation manner of the embodiment of the present disclosure, the correction module is specifically configured to: determine the ratio of the resolution of the second calibration image to the original distorted image as the size ratio coefficient, and determine the first calibration The difference in the number of pixels in the horizontal and vertical directions between the image and the second calibration image is the difference in edge size.

As an optional implementation manner of the embodiment of the present disclosure, the correction module is specifically configured to: determine the resolution ratio between the second calibration image and the original distorted image, and combine the resolution ratio with the digital zoom of the wide-angle lens The ratio of multiples is used as the size scale factor; determine the first ratio between the number of pixels in the horizontal direction of the second calibration image and the digital zoom multiple, determine the number of pixels in the horizontal direction of the second calibration image and The first difference of the first ratio determines the second difference in the number of pixels in the horizontal direction between the first calibration image and the second calibration image; and determines the vertical direction of the second calibration image The second ratio of the number of pixels of the second calibration image to the digital zoom factor, determine the third difference between the number of pixels of the second calibration image in the vertical direction and the second ratio, and determine the first calibration image and the second ratio The fourth difference value of the number of pixels in the vertical direction of the second calibration image; determine the sum of the first difference value and the second difference value, and the difference between the third difference value and the fourth difference value and are the edge size difference.

As an optional implementation manner of the embodiment of the present disclosure, the correction module is further configured to:

Translating the distorted image coordinates according to the edge size difference;

Scale the translated distorted image coordinates according to the size scale coefficient.

As an optional implementation manner of the embodiment of the present disclosure, the calculation module is specifically configured to:

A photographic device is provided with the device for correcting image distortion of a wide-angle lens according to any one of the above embodiments.

An electronic device comprising: a memory and one or more processors, the memory is configured as a module storing computer-readable instructions that, when executed by the processor, cause the One or more processors execute the steps of the method for correcting wide-angle lens image distortion provided by any embodiment of the present disclosure.

One or more non-volatile storage media storing computer-readable instructions, when the computer-readable instructions are executed by one or more processors, the one or more processors execute the correction wide-angle lens provided by any embodiment of the present disclosure The steps of the image warping method.

Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the disclosure. The objectives and other advantages of the disclosure will be realized and attained by the structure particularly pointed out in the written description, claims hereof as well as the accompanying drawings, the details of one or more embodiments of the disclosure being set forth in the accompanying drawings and the description below.

In order to make the above objects, features and advantages of the present disclosure more comprehensible, optional embodiments are given below and described in detail in conjunction with the accompanying drawings.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description serve to explain the principles of the disclosure.

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, In other words, other drawings can also be obtained from these drawings without paying creative labor.

FIG. 1 is a flowchart of a method for correcting image distortion of a wide-angle lens according to one or more embodiments of the present disclosure;

Fig. 2 is a schematic diagram of multi-resolution size image distortion correction according to one or more embodiments of the present disclosure;

FIG. 3 is a schematic structural diagram of an apparatus for correcting image distortion of a wide-angle lens according to one or more embodiments of the present disclosure;

Fig. 4 is a schematic structural diagram of an electronic device according to one or more embodiments of the present disclosure.

Detailed ways

In order to understand the characteristics and technical content of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure will be described in detail below in conjunction with the accompanying drawings. The attached drawings are only for reference and description, and are not intended to limit the embodiments of the present disclosure. In the following technical description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the disclosed embodiments. However, one or more embodiments may be practiced without these details. In other instances, well-known structures and devices may be shown simplified in order to simplify the drawings.

The method, device, and photographic equipment for correcting image distortion of a wide-angle lens according to embodiments of the present disclosure will be described below with reference to FIGS. 1-4 .

FIG. 1 is a flowchart of a method for correcting image distortion of a wide-angle lens according to an embodiment of the present disclosure. As shown in Figure 1, the method includes steps S1 to S5:

Step S1: Input the original distorted image and the preset first calibration image.

Wherein, the original distorted image is, for example, an image taken by a wide-angle lens of a camera, and the image has distortion caused by wide-angle shooting. The first calibration image is a preset calibration image.

Step S2: Determine a second calibration image according to the original distorted image and the first calibration image.

Step S3: Calculate the distorted image coordinates corresponding to the second calibration image according to the distortion parameters of the first calibration image and the distortion mathematical model.

It can be understood that, since the first calibration image is a preset calibration image, correspondingly, the distortion mathematical model of the first calibration image may also be preset, that is, the distortion parameter corresponding to the first calibration image is calculated in advance. For example, a checkerboard image can be used to calculate a distortion parameter conforming to a distortion mathematical model, and the use of a checkerboard image to calculate a distortion parameter belongs to the prior art, and details will not be described here.

In a specific embodiment, when calculating the distorted image coordinates corresponding to the second calibration image, the distorted image coordinates corresponding to the entire image of the second calibration image can be calculated, for example, the distorted image corresponding to each pixel in the second calibration image can be calculated separately Coordinates, thus, can improve the integrity and accuracy of data, which in turn helps to improve the accuracy of image correction.

In another specific embodiment, instead of calculating all the distorted image coordinates corresponding to the entire image of the second calibration image, it is only necessary to calculate the distorted image coordinates corresponding to the coordinates of the second calibration image at intervals. For the coordinates in the interval, you can Estimated by interpolation. For example, in the second calibration image, points are taken according to preset intervals, the distorted image coordinates corresponding to these points are calculated, and then the distorted image coordinates corresponding to other points between adjacent points are estimated by interpolation, which is different from calculating the whole Compared with the distorted image coordinates corresponding to an image, this method can reduce the complexity of the algorithm, reduce the amount of calculation, and improve the calculation efficiency.

Step S4: Determine the difference parameter of the second calibration image, and correct the coordinates of the distorted image according to the difference parameter.

Step S5: output the corrected image according to the pixel values corresponding to the corrected distorted image coordinates.

In a specific embodiment, the coordinates of the corrected distorted image are probably not integers, that is, there are decimal points in the coordinate values, so the calculated coordinates can be rounded, for example, the nearest integer coordinate to the coordinate is selected, and the corresponding integer coordinate The pixel value is assigned to the pixel value corresponding to the coordinates of the corrected image to obtain the corrected image and output the corrected image. In some other embodiments, an interpolation method may also be used to obtain pixel values of the distorted image coordinates, such as bilinear interpolation and the like.

Therefore, in the method for correcting the image distortion of the wide-angle lens in the embodiment of the present disclosure, the second calibration image is determined according to the original distorted image and the first calibration image, and the difference parameters of the distortion image corresponding to the second calibration image and the second calibration image can be calculated for any The resolution of the original distorted image is corrected, that is, the pixel value corresponding to the corrected distorted image coordinate is assigned to the corrected image, and the corrected image is output. Since the first calibration image is a preset calibration image, correspondingly, the distortion mathematical model of the first calibration image may also be preset, that is, the distortion parameter corresponding to the first calibration image is calculated in advance. Therefore, this method only needs to calculate a set of distortion parameters, that is, calculate the distortion parameters corresponding to the first calibration image, and then realize the correction of the original wide-angle distorted image with any resolution, avoiding the existence of distortion in the image captured by the wide-angle camera. When multiple resolutions are used, multiple sets of distortion parameters need to be calibrated, which greatly simplifies the calibration process.

In a specific embodiment, the first calibration image is an image with the largest resolution captured by a wide-angle camera, and the distortion parameter error corresponding to this image is the smallest, thus, it is possible to avoid the distortion parameter error calibrated when the small resolution image is calibrated If it is too large, the accuracy of the correction is improved.

In one embodiment of the present disclosure, in step S2, determining the second calibration image according to the original distorted image and the first calibration image includes: determining that the resolution of the first calibration image is the same as the aspect ratio of the original distorted image The image corresponding to the maximum resolution of is used as the second calibration image. In other words, under the preset resolution corresponding to the first calibration image, an image corresponding to the maximum resolution with the same aspect ratio as the original distorted image is searched for. For example, the acquired resolution of the distorted image is compared with the preset maximum resolution of the first calibration image, and the image with the same aspect ratio as the original distorted image and the largest resolution is found, which is the second Calibration image. Assuming that the resolution of the first calibration image is 2560x1920, the resolution of the currently captured original distorted image is 1920x1080, and its aspect ratio is 16:9, then under the resolution of the first calibration image, the aspect ratio is also 16:9 The maximum resolution of is 2560x1440, and the image corresponding to the resolution of 2560x1440 is the second calibration image.

In an embodiment of the present disclosure, the difference parameter of the second calibration image includes: a size ratio coefficient between the second calibration image and the original distorted image, and an edge size difference between the first calibration image and the second calibration image.

In one embodiment of the present disclosure, determining the difference parameter of the second calibration image includes:

Step S31-1: Determine the ratio of the resolution of the second calibration image to the original distorted image as the size ratio coefficient.

Step S32-1: Determine the difference in the number of pixels between the first calibration image and the second calibration image in the horizontal and vertical directions as the edge size difference, this process is the difference parameter of the second calibration image when there is no digital zoom in the camera determination process.

It can be understood that the resolution refers to the number of pixels in the horizontal (horizontal) and vertical (vertical) directions of the image, for example: 1920x1080 resolution, that is, the image has 1920 pixels in the horizontal direction and 1080 pixels in the vertical direction. Ratio, that is, the size ratio coefficient is the ratio of the number of pixels in the horizontal direction between the second calibration image and the original distorted image, or the ratio of the number of pixels in the vertical direction between the second calibration image and the original distorted image. It can also be understood that both the first calibration image and the second calibration image include a plurality of edges, and thus the edge size difference includes the corresponding size difference between the first calibration image and the second calibration image at each edge.

Taking FIG. 2 as an example for illustration, FIG. 2 is a schematic diagram of multi-resolution size image distortion correction according to an embodiment of the present disclosure.

In a specific embodiment, in the example shown in Figure 2, the resolution of the first calibration image is 2560*1920, the resolution of the original distorted image is 1920*1080, and the aspect ratio is 16:9, then according to the first The resolution of the second calibration image determined by the calibration image and the original distorted image is 2560*1440, its size ratio factor is 4:3=1.1, and the edge size difference is 1920-1440=480. It can be understood that the edge size difference includes the upper, lower and left and right parts as shown in Figure 2, then the excess length of the edge in the transverse direction is 0, that is, the size difference in the left and right directions is 0; The redundant length of the upper edge in the longitudinal direction is (1920-1440)÷2=240, that is, the size difference in the upper and lower directions is 240 respectively.

Step S31-2: Determine the resolution ratio of the second calibration image to the original distorted image, and use the ratio of the resolution ratio to the digital zoom factor of the wide-angle lens as the size ratio factor.

Step S32-2: determine the first ratio between the number of pixels in the horizontal direction of the second calibration image and the digital zoom factor, determine the first difference between the number of pixels in the horizontal direction of the second calibration image and the first ratio, and determine the first ratio The second difference in the number of pixels in the horizontal direction between the first calibration image and the second calibration image; The third difference between the number of pixels in the vertical direction and the second ratio determines the fourth difference in the number of pixels in the vertical direction between the first calibration image and the second calibration image; determine the difference between the first difference and the second difference and, and the sum of the third difference and the fourth difference is the edge size difference. This process is the process of determining the difference parameters of the second calibration image when the camera has digital zoom. The principle of digital zoom is that the image is first enlarged and then cropped. process, so the actual captured image is cropped relative to the unzoomed image, and when calculating the distortion parameters, this part of the crop needs to be subtracted. Therefore, it is necessary to consider the influence of the digital zoom factor on the calculation of the distorted image coordinates.

Specifically, most of the current camera equipment supports digital zoom technology, but the digital zoom of the wide-angle lens will cause the correction of the distorted image based on the traditional method to be abnormal. The embodiment of the present disclosure calculates the difference parameter of the second calibration image under the digital zoom , and the original distorted image with any resolution can be corrected through the distorted image coordinates corresponding to the second calibration image. This method only needs to calculate the distortion parameters corresponding to the first calibration image, which avoids multiple resolutions in the image captured by the wide-angle camera. When the rate is high, multiple sets of distortion parameters need to be calibrated, which simplifies the correction process. At the same time, the influence of digital zoom on the calculation of the distorted image coordinates is considered, which further improves the accuracy of the correction.

In a specific embodiment, the first calibration image is an image with the maximum resolution taken by a wide-angle camera, the resolution of which is 2560*1920, the resolution of the original distorted image is 1920*1080, and the aspect ratio is 16:9. Then the resolution of the second calibration image is 2560*1440, assuming that the digital zoom factor of the wide-angle camera is 1.2x, the size ratio factor is 4:3:1.2=1.1, and the edge size difference needs to be the edge size difference when there is no digital zoom Add 2560-2560/1.2=426 and 1440-1440/1.2=240 to the value. It can be understood that the edge size difference includes upper, lower and left and right parts, then the excess length of the edge in the horizontal direction is 426÷2=213.3, and the excess length of the edge in the vertical direction is 240÷2+240=360.

In one embodiment of the present disclosure, correcting the distorted image coordinates according to the difference parameters includes:

Step S41: Translate the distorted image coordinates according to the edge size difference.

Step S42: scaling the translated distorted image coordinates according to the size ratio coefficient.

Specifically, translating the distorted image coordinates according to the edge size difference includes: translating the distorted image coordinates corresponding to the second calibration image in the lateral direction by an excess length of the edge in the lateral direction, that is, For the size difference, the distance to translate the distorted image coordinates corresponding to the second calibration image in the vertical direction is the excess length of the edge in the vertical direction, that is, the size difference in the vertical direction. Scale the translated distorted image coordinates according to the size scale factor, and the zoom ratio is the size scale factor.

In a specific embodiment, when there is no digital zoom in the wide-angle lens, the resolution of the first calibration image is 2560*1920, the resolution of the original distorted image is 1920*1080, and the aspect ratio is 16:9, then the second calibration image The resolution is 2560*1440, the translation distance of the distorted image coordinates corresponding to the second calibration image is 0 in the horizontal direction, and the translation distance in the vertical direction is 240, and then the distorted image coordinates after translation are scaled, and the scaled The scaling ratio is 4:3=1.33. For example, when there is no digital zoom in the wide-angle lens, assuming that the resolution of the first calibration image is 2560*1920, the resolution of the original distorted image is 1920*1080, and the aspect ratio is 16:9, then the resolution of the second calibration image The resolution is 2560*1440, and the coordinates of the distorted image corresponding to the second calibration image are, for example, (72.8, 285.6), and the coordinates are translated to the left by 0 in the horizontal direction and 240 in the vertical direction to obtain (72.8, 45.6), Then divide by the proportional coefficient 1.33 to get the corrected distortion coordinates (54.6, 34.2). Since the coordinates are not integers, select the integer coordinates closest to the coordinates, and assign the pixel value corresponding to the integer coordinates to the pixel corresponding to the corrected image coordinates value, get the corrected image, and output the corrected image. The pixel values of the distorted image coordinates can also be obtained by interpolation, such as bilinear interpolation, and then the pixel values are assigned to the pixel values corresponding to the corrected image coordinates to obtain the corrected image.

When the wide-angle lens has digital zoom, assuming that the digital zoom factor is 1.2x, the resolution of the first calibration image is 2560*1920, the resolution of the original distorted image is 1920*1080, and the aspect ratio is 16:9, then the second calibration The resolution of the image is 2560*1440, the translation distance of the distorted image coordinates corresponding to the second calibration image is 213.3 in the horizontal direction, and the translation distance in the vertical direction is 360, and then the distorted image coordinates after translation are scaled, zoomed The scaling ratio is 4:3:1.2=1.1. For example, when the wide-angle lens has digital zoom, assuming that the digital zoom factor is 1.2x, the resolution of the first calibration image is 2560*1920, the resolution of the original distorted image is 1920*1080, and the aspect ratio is 16:9. Then the resolution of the second calibration image is 2560*1440, and the coordinates of the distorted image corresponding to the second calibration image are, for example, (274,398), and the coordinates are translated 213.3 to the left in the horizontal direction and 360 in the vertical direction to obtain (60.7 , 38), and then divided by the proportional coefficient 1.1 to obtain the corrected distortion coordinates (54.6, 34.2). Since the coordinates are not integers, select the integer coordinates closest to the coordinates, and assign the pixel value corresponding to the integer coordinates to the corrected image The pixel values corresponding to the coordinates are used to obtain the corrected image and output the corrected image. The pixel values of the distorted image coordinates can also be obtained by interpolation, such as bilinear interpolation, and then the pixel values are assigned to the pixel values corresponding to the corrected image coordinates to obtain the corrected image.

To sum up, according to the method for correcting image distortion of a wide-angle lens according to the embodiment of the present disclosure, it is not necessary to calibrate multiple sets of distortion parameters, and it is only necessary to calculate a set of distortion parameters corresponding to a set of maximum resolution images to realize the correction of the original wide-angle distorted image of any resolution. Calibration greatly simplifies the calibration process, and at the same time avoids the large error of the calibrated distortion parameters when the small-resolution image is calibrated, thereby improving the accuracy of the calibration.

It should be understood that although the various steps in the flow chart of FIG. 1 are displayed sequentially as indicated by the arrows, these steps are not necessarily executed sequentially in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least some of the steps in Fig. 1 may include multiple sub-steps or multiple stages, these sub-steps or stages are not necessarily executed at the same time, but may be executed at different times, the execution of these sub-steps or stages The order is not necessarily performed sequentially, but may be performed alternately or alternately with at least a part of other steps or sub-steps or stages of other steps.

A further embodiment of the present disclosure also discloses a device for correcting image distortion of a wide-angle lens. FIG. 3 is a schematic structural diagram of a device for correcting image distortion of a wide-angle lens according to an embodiment of the present disclosure. As shown in FIG. 3 , the device 10 includes:

The input module 11 is configured to input the original distorted image and a preset first calibration image, and the determination module 12 is configured to determine a second calibration image according to the original distorted image and the first calibration image, and a calculation module 13, It is configured to calculate the distorted image coordinates corresponding to the second calibration image according to the distortion parameters of the first calibration image and the distortion mathematical model, and the correction module 14 is configured to determine the difference parameter of the second calibration image, according to the The difference parameter corrects the distorted image coordinates, and the output module 15 is configured to output the corrected image according to the pixel values corresponding to the corrected distorted image coordinates.

In an embodiment of the present disclosure, the determining module 12 is specifically configured to: determine an image corresponding to a maximum resolution under the resolution of the first calibration image that is the same as the aspect ratio of the original distorted image, as the Second calibration image.

In an embodiment of the present disclosure, the correction module 14 is specifically configured to: determine the difference parameter of the second calibration image, and then correct the coordinates of the distorted image according to the difference parameter, wherein the difference parameter includes : the scale factor between the second calibration image and the original distorted image, and the edge size difference between the first calibration image and the second calibration image.

In one embodiment of the present disclosure, the correction module 14 is specifically configured to: determine the ratio of the resolution of the second calibration image to the original distorted image as the size scale factor, and determine the ratio of the resolution of the first calibration image to the The difference between the number of pixels in the horizontal direction and the vertical direction of the second calibration image is the difference in the edge size.

In an embodiment of the present disclosure, the correction module 14 is further configured to: determine the resolution ratio of the second calibration image to the original distorted image, and use the ratio of the resolution ratio to the digital zoom factor of the wide-angle lens as the determined The size ratio factor, and determine the first ratio of the number of pixels in the horizontal direction of the second calibration image to the digital zoom factor, and determine the ratio of the number of pixels in the horizontal direction of the second calibration image to the first The first difference of the ratio determines the second difference between the number of pixels in the horizontal direction between the first calibration image and the second calibration image; and determines the number of pixels in the vertical direction of the second calibration image and the second ratio of the digital zoom factor, determine the third difference between the number of pixels in the vertical direction of the second calibration image and the second ratio, and determine the difference between the first calibration image and the second calibration image The fourth difference of the number of pixels in the vertical direction of the image; determine the sum of the first difference and the second difference, and the sum of the third difference and the fourth difference is the Edge size difference.

In an embodiment of the present disclosure, the correction module 14 is further configured to: translate the distorted image coordinates according to the edge size difference.

The correction module 14 is further configured to: scale the translated distorted image coordinates according to the size scale coefficient.

According to the device 10 for correcting wide-angle lens image distortion according to the embodiment of the present disclosure, the device 10 does not need to calibrate multiple sets of distortion parameters, and only needs to calculate a set of distortion parameters corresponding to the maximum resolution image to realize the correction of the original wide-angle distorted image of any resolution , which greatly simplifies the calibration process, and at the same time avoids the large error of the calibrated distortion parameters when the small-resolution image is calibrated, thereby improving the accuracy of the calibration.

A further embodiment of the present disclosure also discloses a photographic device, which is provided with the device 10 for correcting image distortion of a wide-angle lens described in any one of the above embodiments.

In a specific embodiment, the camera device is, for example but not limited to, a camera with a wide-angle lens, a mobile phone, a tablet computer, a wearable device and other electronic devices.

It should be noted that when the photographic equipment in the embodiment of the present disclosure corrects the image distortion of the wide-angle lens, its specific implementation method is similar to that of the device for correcting the image distortion of the wide-angle lens in the embodiment of the present disclosure. For details, please refer to the description of the device part. To reduce redundancy, details will not be repeated here.

According to the photographic equipment of the embodiments of the present disclosure, the photographic equipment does not need to calibrate multiple sets of distortion parameters, and only needs to calculate a set of distortion parameters corresponding to the maximum resolution image to realize the correction of the original wide-angle distorted image with any resolution, which greatly simplifies The correction process is simplified, and at the same time, the error of the calibrated distortion parameters is too large when the small-resolution image is calibrated, thereby improving the accuracy of the correction.

The above-mentioned computer-readable storage medium may be a transitory computer-readable storage medium, or a non-transitory computer-readable storage medium.

According to the computer-readable storage medium of the embodiment of the present disclosure, when the program for correcting the image distortion of the wide-angle lens stored thereon is executed by the processor, it only needs to calculate the distortion parameters corresponding to a set of maximum-resolution images to realize the original The correction of the wide-angle distorted image greatly simplifies the correction process, and at the same time avoids the large error of the calibrated distortion parameters when the small-resolution image is calibrated, thereby improving the accuracy of the correction.

A further embodiment of the present disclosure also discloses an electronic device.

In some embodiments, the electronic device includes the device 10 for correcting image distortion of a wide-angle lens as described in any one of the above-mentioned embodiments of the present disclosure. That is, the electronic device may include: an input module 11 for inputting an original distorted image and a preset first calibration image; and a determination module for determining a second calibration image according to the original distorted image and the first calibration image 12; and a calculation module 13 for calculating the coordinates of the distorted image corresponding to the second calibration image according to the distortion parameter of the first calibration image and the distortion mathematical model, and for determining the difference parameter of the second calibration image, A correction module 14 for correcting the distorted image coordinates according to the difference parameters, and an output module 15 for outputting a corrected image according to pixel values corresponding to the corrected distorted image coordinates. Therefore, in some embodiments, when the electronic device is used to correct the distortion of the wide-angle lens image, its specific implementation method is similar to the device 10 for correcting the wide-angle lens image distortion described in any of the above-mentioned embodiments of the present disclosure. For details, please refer to the aforementioned The description of the part of the device 10 is omitted here to reduce redundancy.

In some other embodiments, as shown in FIG. 4 , the electronic device includes: a processor 1000, a memory 2000; and a computer that is stored on the memory 2000 and can run on the processor 1000 to correct the image distortion of the wide-angle lens The readable instructions, when the computer-readable instructions for correcting the image distortion of the wide-angle lens are executed by the processor 1000 , cause the processor 1000 to execute the steps of the method for correcting the image distortion of the wide-angle lens provided by the embodiment of the present disclosure.

In a specific embodiment, the electronic device is, for example, but not limited to a camera device, and the camera device includes, for example, but not limited to a camera with a wide-angle lens, a mobile phone, a tablet computer, a wearable device, and the like.

According to the electronic device of the embodiment of the present disclosure, the device does not need to calibrate multiple sets of distortion parameters, and only needs to calculate a set of distortion parameters corresponding to the maximum resolution image to realize the correction of the original wide-angle distorted image with any resolution, which greatly simplifies The calibration process avoids the large error of the calibrated distortion parameters when the small-resolution image is calibrated, thereby improving the accuracy of the calibration.

Wherein, there may be one or more processors 1000 mentioned above, and one processor 1000 is taken as an example in FIG. 4 .

As shown in FIG. 4 , the electronic device may also include a communication interface (Communication Interface) 3000 and a bus 4000. Wherein, the processor 1000 , the memory 2000 , and the communication interface 3000 can communicate with each other through the bus 4000 . The communication interface 3000 can be used for information transmission. The processor 1000 may invoke logic instructions in the memory 2000 to execute the method for correcting image distortion of a wide-angle lens in the above embodiments.

In addition, the logic instructions in the above-mentioned memory 2000 may be implemented in the form of software functional units and may be stored in a computer-readable storage medium when sold or used as an independent product.

As a computer-readable storage medium, the memory 2000 can be used to store software programs and computer-executable programs, such as program instructions/modules corresponding to the methods in the embodiments of the present disclosure. The processor 1000 runs software programs, instructions and modules stored in the memory 2000 to execute functional applications and data processing, that is, to implement the method for correcting image distortion of the wide-angle lens in the above method embodiments.

The memory 2000 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application program required by at least one function; the data storage area may store data created according to the use of the terminal device, and the like. In addition, the memory 2000 may include a high-speed random access memory, and may also include a non-volatile memory.

The technical solutions of the embodiments of the present disclosure can be embodied in the form of software products, which are stored in a storage medium and include one or more instructions to make a computer device (which can be a personal computer, a server, or a network equipment, etc.) to perform all or part of the steps of the method described in the embodiments of the present disclosure. The aforementioned storage medium can be a non-transitory storage medium, including: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disc, etc. A medium that can store program code, or a transitory storage medium.

When used in the present disclosure, although the terms 'first', 'second', etc. may be used in the present disclosure to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be called a second element without changing the meaning of the description, and likewise, a second element could be called a first element, as long as all occurrences of "first element" are renamed consistently and all occurrences of "Second component" can be renamed consistently. Both the first element and the second element are elements, but may not be the same element.

The aspects, implementations, implementations or features of the described embodiments can be used alone or in any combination. Aspects of the described embodiments can be implemented by software, hardware or a combination of hardware and software. The described embodiments may also be embodied by a computer-readable medium storing computer-readable code comprising instructions executable by at least one computing device. The computer readable medium can be associated with any data storage device that can store data that can be read by a computer system. By way of example, computer readable media may include read only memory, random access memory, CD-ROM, HDD, DVD, magnetic tape, and optical data storage devices, among others. The computer readable medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

The above technical description may refer to the accompanying drawings, which form a part of this disclosure, and in which are shown by way of description implementations in accordance with the described embodiments. While these embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments, these embodiments are not limiting; as such, other embodiments can be used and without departing from the scope of the described embodiments Circumstances can also be changed. For example, the order of operations described in the flow diagrams is non-limiting, and thus the order of two or more operations illustrated in and described with respect to the flow diagrams may be changed according to several embodiments. As another example, in several embodiments, one or more operations illustrated in and described with respect to the flowcharts are optional, or may be deleted. Additionally, certain steps or functionality may be added to the disclosed embodiments, or the order of two or more steps permuted. All such variations are considered to be encompassed by the disclosed embodiments as well as the claims.

Additionally, terminology was used in the above technical description to provide a thorough understanding of the described embodiments. However, undue detail is not required to implement the described embodiments. Thus, the foregoing description of the embodiments has been presented for purposes of illustration and description. The embodiments presented in the foregoing description, and examples disclosed according to these embodiments, are provided individually to add context and to facilitate understanding of the described embodiments. The above description is not intended to be exhaustive or to limit the described embodiments to the precise form of the disclosure. Several modifications, alternatives, and variations are possible in light of the above teachings. In some instances, well known process steps have not been described in detail in order not to unnecessarily obscure the described embodiments.

In the description of this specification, references to the terms "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific examples," or "some examples" are intended to mean that the implementation A specific feature, structure, material, or characteristic described by an embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example.

Although the embodiments of the present disclosure have been shown and described, those skilled in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present disclosure. The scope of the present disclosure is defined by the claims and their equivalents.

Industrial Applicability

The correction method for wide-angle lens image distortion provided by this disclosure can realize the correction of the original wide-angle distorted image with any resolution, greatly simplifies the correction process, and effectively avoids the distortion parameter error of calibration when the small-resolution image is calibrated If the situation is too large, the accuracy of the correction is improved, and it has strong industrial applicability.

Claims

A method for correcting image distortion of a wide-angle lens, characterized in that it comprises:

Input the original distorted image and the preset first calibration image;

determining a second calibration image based on the original distorted image and the first calibration image;

calculating the distorted image coordinates corresponding to the second calibration image according to the distortion parameters of the first calibration image and the distortion mathematical model;

determining a difference parameter of the second calibration image, and correcting the distorted image coordinates according to the difference parameter;

Output the corrected image according to the pixel values corresponding to the corrected distorted image coordinates.
The method for correcting image distortion of a wide-angle lens according to claim 1, wherein determining a second calibration image according to the original distorted image and the first calibration image comprises: determining the resolution of the first calibration image An image corresponding to the maximum resolution with the same aspect ratio as the original distorted image is used as the second calibration image.
The method for correcting image distortion of a wide-angle lens according to claim 1, wherein the difference parameters include: a size ratio coefficient between the second calibration image and the original distorted image, and the first calibration image and the original distorted image. The edge size difference of the second calibration image.
The method for correcting wide-angle lens image distortion according to claim 3, wherein determining the difference parameter of the second calibration image comprises:

determining the resolution ratio of the second calibration image to the original distorted image as the size scaling factor;

Determining the difference in the number of pixels between the first calibration image and the second calibration image in the horizontal direction and the vertical direction as the edge size difference.
The method for correcting wide-angle lens image distortion according to claim 3, wherein determining the difference parameter of the second calibration image comprises:

Determine the resolution ratio of the second calibration image to the original distorted image, and use the ratio of the resolution ratio to the digital zoom factor of the wide-angle lens as the size ratio factor;

Determine the first ratio of the number of pixels in the horizontal direction of the second calibration image to the digital zoom factor, and determine the first difference between the number of pixels in the horizontal direction of the second calibration image and the first ratio , determining a second difference between the number of pixels in the horizontal direction of the first calibration image and the second calibration image; and determining the number of pixels in the vertical direction of the second calibration image and the digital zoom factor The second ratio, determine the third difference between the number of pixels in the vertical direction of the second calibration image and the second ratio, and determine the pixels in the vertical direction of the first calibration image and the second calibration image A fourth difference in number; determine the sum of the first difference and the second difference, and the sum of the third difference and the fourth difference as the edge size difference.
The method for correcting wide-angle lens image distortion according to any one of claims 3-5, wherein correcting the distorted image coordinates according to the difference parameters includes:

Translating the distorted image coordinates according to the edge size difference;

Scale the translated distorted image coordinates according to the size scale coefficient.
The method according to claim 1, wherein the calculating the distorted image coordinates corresponding to the second calibration image according to the distortion parameters of the first calibration image and the distortion mathematical model comprises:

Calculate the distorted image coordinates corresponding to each pixel in the second calibration image according to the distortion parameters of the first calibration image and the distortion mathematical model.
The method according to claim 1, wherein the calculating the distorted image coordinates corresponding to the second calibration image according to the distortion parameters of the first calibration image and the distortion mathematical model further comprises:

According to the distortion parameters and the distortion mathematical model of the first calibration image, pixel points are taken out according to preset intervals, and the coordinates of the distorted image corresponding to the pixel points are calculated;

Estimating the distorted image coordinates corresponding to other points between adjacent points of the pixel point according to an interpolation method.
The method according to claim 1, wherein said outputting the corrected image according to the pixel value corresponding to the corrected distorted image coordinates comprises:

Rounding the pixel value corresponding to the corrected distorted image coordinates to obtain the corrected image;

The corrected image is output.
The method according to claim 6, wherein said translating said distorted image coordinates according to said edge size difference comprises:

Taking the distance translated in the lateral direction by the distorted image coordinates corresponding to the second calibration image as the lateral size difference;

The distance that the coordinates of the distorted image corresponding to the second calibration image are translated in the longitudinal direction is taken as the dimension difference in the longitudinal direction.
A device for correcting image distortion of a wide-angle lens, characterized in that it comprises:

The input module is configured to input the original distorted image and the preset first calibration image;

A determining module configured to determine a second calibration image according to the original distorted image and the first calibration image;

A calculation module configured to calculate the distorted image coordinates corresponding to the second calibration image according to the distortion parameters of the first calibration image and the distortion mathematical model;

A correction module configured to determine a difference parameter of the second calibration image, and correct the coordinates of the distorted image according to the difference parameter;

The output module is configured to output the corrected image according to the pixel values corresponding to the corrected distorted image coordinates.
The device according to claim 11, wherein the determining module is further configured to:

An image corresponding to a maximum resolution below the resolution of the first calibration image and having the same aspect ratio as the original distorted image is determined as the second calibration image.
The device according to claim 11, wherein the correction module is specifically configured to:

determining the resolution ratio of the second calibration image to the original distorted image as the size scaling factor, and determining the difference in the number of pixels between the first calibration image and the second calibration image in the horizontal and vertical directions is the edge size difference.
The device according to claim 11, wherein the correction module is specifically configured to:

Determine the resolution ratio of the second calibration image to the original distorted image, and use the ratio of the resolution ratio to the digital zoom factor of the wide-angle lens as the size ratio factor;

Determine the first ratio of the number of pixels in the horizontal direction of the second calibration image to the digital zoom factor, and determine the first difference between the number of pixels in the horizontal direction of the second calibration image and the first ratio , determining a second difference between the number of pixels in the horizontal direction between the first calibration image and the second calibration image; and determining the difference between the number of pixels in the vertical direction of the second calibration image and the digital zoom factor The second ratio is to determine the third difference between the number of pixels in the vertical direction of the second calibration image and the second ratio, and to determine the number of pixels in the vertical direction between the first calibration image and the second calibration image A fourth difference of the number; determine the sum of the first difference and the second difference, and the sum of the third difference and the fourth difference as the edge size difference.
The device according to claim 11, wherein the correction module is specifically configured to:

Translating the distorted image coordinates according to the edge size difference;

Scale the translated distorted image coordinates according to the size scale coefficient.
The device according to claim 11, wherein the calculation module is specifically configured to:

Calculate the distorted image coordinates corresponding to each pixel in the second calibration image according to the distortion parameters of the first calibration image and the distortion mathematical model.
The device according to claim 11, wherein the calculation module is specifically configured to:

According to the distortion parameters and the distortion mathematical model of the first calibration image, pixel points are taken out according to preset intervals, and the coordinates of the distorted image corresponding to the pixel points are calculated;

Estimating the distorted image coordinates corresponding to other points between adjacent points of the pixel point according to an interpolation method.
A photographic device, characterized in that it is provided with a device for correcting image distortion of a wide-angle lens as claimed in claim 11.
An electronic device, characterized by comprising: a memory and one or more processors, the memory is configured as a module storing computer-readable instructions, and when the computer-readable instructions are executed by the processor, the The one or more processors execute the method for correcting image distortion of a wide-angle lens according to any one of claims 1-10.
One or more non-volatile storage media storing computer-readable instructions, when the computer-readable instructions are executed by one or more processors, the one or more processors execute any one of claims 1-10 A method for correcting image distortions of wide-angle lenses.