CN116017158B

CN116017158B - Optical anti-shake calibration method and device

Info

Publication number: CN116017158B
Application number: CN202310047676.5A
Authority: CN
Inventors: 刘洋; 盛家豪; 徐荣跃
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2023-01-31
Filing date: 2023-01-31
Publication date: 2023-09-15
Anticipated expiration: 2043-01-31
Also published as: CN116017158A

Abstract

The application provides an optical anti-shake calibration method and equipment, relates to the technical field of optical electronic devices, and is used for solving the problem of low accuracy of OIS calibration. The method comprises the following steps: and acquiring N images acquired by the camera module at a first shooting state and a first preset calibration plate comprising at least one characteristic point. N is larger than 2, and N images are respectively set to different values corresponding to motors of the camera module. The first shooting state includes: the camera module vibrates and the OIS function of the camera module is started; when the OIS function of the camera module is started, the motor drives the lens of the camera module to move when the image is acquired so as to compensate the blurring caused by the vibration of the camera module. And obtaining the jitter condition of the characteristic points in each image, and determining the jitter center of each image according to the jitter condition of the characteristic points. And searching target images of which the distances between the jitter centers and the image centers meet preset conditions from the N images. And obtaining a target gain corresponding to the target image, and determining the target gain as a calibrated gain value of the motor.

Description

Optical anti-shake calibration method and device

Technical Field

The application relates to the technical field of optical electronic devices, in particular to an optical anti-shake calibration method and optical anti-shake calibration equipment.

Background

The optical image stabilizer (Optical Image Stabilizer, OIS) compensates imaging blur caused by camera shake during shooting by moving the lens group or the photosensitive chip, so as to achieve the functions of shock absorption and shake prevention, and make the shot picture clear and stable. For the camera module with the OIS anti-shake function, in order to ensure the OIS anti-shake effect, the OIS function needs to be calibrated before the camera module is put into use.

One calibration method commonly used in the related art is to use a calibration plate with a single characteristic point to perform OIS calibration on a camera module, set the single characteristic point in the center of the calibration plate, and perform OIS calibration on the camera module to be calibrated based on the information of the single characteristic point in the shot image after the camera module to be calibrated is used for shooting the image on the calibration plate.

Periscope type realization modules (Periscope lens), which are called as 'internal zoom' lenses, refer to that optical zooming is completed inside a machine body. When the above method is used for carrying out OIS calibration on the periscope type camera module, after the position of the calibration plate is fixed, the positions of single features in the image are not necessarily in the center of the image when different periscope type camera modules shoot the calibration plate. Under the condition, the periscope type camera module is subjected to OIS calibration, and the problem that the center of image evaluation is far from the center of a lens picture and the accuracy of OIS calibration is low easily occurs.

Disclosure of Invention

The embodiment of the application provides an optical anti-shake calibration method and optical anti-shake calibration equipment, which are used for solving the problems that the center of image evaluation is far from the center of a lens picture and the accuracy of OIS calibration is low when the periscope type camera module is subjected to OIS calibration. In order to achieve the above purpose, the embodiment of the present application adopts the following technical scheme:

in a first aspect, there is provided a calibration method for optical anti-shake, the method comprising:

and acquiring N images acquired by the camera module under a first shooting state on a first preset calibration plate. The first preset calibration plate comprises at least one characteristic point, and N is a positive integer greater than 2; n images are acquired when the motors of the camera modules are set to different gains. The first shooting state includes: the camera shooting module vibrates and the optical anti-shake function of the camera shooting module is started; when the camera shooting module is used for collecting images in a state that the optical anti-shake function of the camera shooting module is started, the motor drives the lens of the camera shooting module to move so as to compensate the blurring caused by the vibration of the camera shooting module. Then, obtaining the jitter condition of the characteristic points in each of the N images, and determining the jitter center of each image according to the jitter condition of the characteristic points in each of the N images; the center of jitter is used to indicate the position in the image where jitter is minimal. Then, searching target images with the distance between the shake center and the image center meeting preset conditions in the N images; the preset condition is used for indicating that the distance between the dithering center of the image and the center of the image is minimum, and the distance is smaller than a first preset threshold value. And finally, acquiring a target gain corresponding to the motor when the target image is acquired, and determining the target gain as a calibrated gain value of the motor.

In the scheme, images acquired by the camera shooting module at different motor gains are analyzed, the position of the shaking center is found in each image, and the target image is found according to whether the distance between the shaking center and the image center is smaller than a certain value or not and the distance is the smallest in N images. Then, a gain value of the motor used to acquire the target image is determined as a calibrated gain value of the motor. Therefore, the position aimed by the OIS calibration can be ensured to be the image center or the position close to the image center as far as possible, namely the position of the picture center of the camera module is positioned, so that the position of the OIS calibration is close to the image center as far as possible, and the OIS calibration accuracy is improved. Meanwhile, the OIS calibration can be completed only by searching the shake centers of different images and determining that the shake centers are close to the image center, so that the OIS calibration process can be completed quickly, the time required by OIS calibration is reduced, and the OIS calibration efficiency is improved.

In one possible implementation manner, obtaining the jitter condition of each feature point in the N images, and determining the jitter center of each image according to the jitter condition of each feature point in the N images may specifically include: firstly, carrying out filtering treatment on N images to obtain N filtered images; the filtered image comprises at least one feature object corresponding to at least one feature point, and each feature point and a fuzzy part corresponding to the corresponding feature point. Since a feature object includes a feature point and its blurred portion, that is, the feature object reflects the magnitude of the blur amount of the corresponding feature point. Therefore, the position of the dithering center in the image corresponding to each of the N filtered images can be determined based on the size of at least one feature object in each of the N filtered images.

In a possible implementation manner, the determining, based on the size of at least one feature object in each of the N filtered images, the position of the dithering center in the image corresponding to each of the N filtered images may specifically include: and searching the minimum feature object in each filtered image of the N filtered images respectively. Then, based on the minimum feature object in each filtered image, the position of the dithering center in the image corresponding to each filtered image is determined. In the scheme, the minimum feature object is searched in the image after the filtering processing, and then the position of the jitter center is determined based on the minimum feature object, so that the position of the jitter center can be quickly and effectively searched.

In a possible implementation manner, determining the position of the dithering center in the image corresponding to each filtered image based on the smallest feature object in each filtered image specifically may include: if the minimum feature object is at the edge of the filtered image and the size of the minimum feature object exceeds a second preset threshold, determining that the jitter center is outside the image corresponding to the target filtered image. And if the minimum feature object is not at the edge of the filtered image or the size of the minimum feature object does not exceed a second preset threshold, determining the position of the jitter center based on the position of the minimum feature object in the target filtered image. And setting a second preset threshold to distinguish whether the dithering center is within the image, and when the dithering center is determined to be outside the image, continuing to adjust the gain of the motor to enable the dithering center to move into the image. After the jitter center is determined to be within the image, the motor gain is adjusted so that the jitter center of the image can be moved to the image center. In this way, it may be convenient to determine an optimal gain value for the motor. The original image acquired by the camera module is subjected to filtering processing, so that the jitter center position can be determined directly by comparing the sizes of the characteristic objects. The fuzzy quantity of the characteristic points does not need to be calculated, the calculated quantity in the calibration process can be reduced, and the efficiency of OIS calibration is improved.

In a possible implementation manner, determining the position of the jitter center based on the position of the minimum feature object in the target filtered image may specifically include: if the minimum feature object includes one feature object, determining the position of the center of the minimum feature object as the position of the jitter center. If the minimum feature object includes more than two feature objects, the position of the jitter center is fitted based on the position of the minimum feature object. Since the first preset calibration plate comprises a plurality of feature points, there may be no feature points in the image center of the acquired image, and therefore, when the shake center is found based on the feature objects, the position of the shake center can be fitted in combination with the minimum feature object, so that the more accurate position of the shake center is obtained.

In a possible implementation manner, acquiring N images acquired by the camera module in the first shooting state on the first preset calibration plate may specifically include: the gain of the motor is increased or decreased from an initial value, and when the motor is set to be different gains, the image acquired by the camera module in the first shooting state on the first preset calibration plate is correspondingly acquired. In the scheme, in the calibration process of optical anti-shake, the gain of the control motor is sequentially increased or decreased, so that the positions of shake centers in different images can be changed towards one direction, and images with shake centers close to the image centers can be found conveniently and quickly. Thus, the OIS calibration speed can be improved.

In one possible implementation manner, obtaining the jitter condition of the feature points in each of the N images, and determining the jitter center of each of the N images according to the jitter condition of the feature points in each of the N images may specifically include: after the current image acquired by the camera shooting module when the motor is set to be the current gain is acquired, the jitter condition of the characteristic points in the current image is acquired, and the jitter center of the current image is determined according to the jitter condition of the characteristic points in the current image. In this embodiment, the method further comprises: and stopping acquiring the image acquired by the camera shooting module to the first preset calibration plate in the first shooting state when the distance between the shake center of the current image and the image center of the current image is determined to meet the preset condition.

In the scheme, after the camera shooting module is adjusted to be a motor gain value each time and an image is acquired, whether the dithering center and the image center of the image meet preset conditions is analyzed. If the preset condition is met, the camera module can not adjust the gain value of the motor any more, and can also not collect new images any more. If the preset condition is not met, the motor gain value corresponding to the image is not the optimal gain value of the motor. At this time, the camera module can continuously adjust the gain value of the motor and collect new images for analysis. Therefore, the image pickup module can be prevented from collecting redundant images, analysis of the redundant images is not needed, the time required for calibration can be reduced, and the OIS calibration speed is improved.

In one possible embodiment, the gain of the motor increases or decreases from an initial value, which may include: in the process of increasing or decreasing the gain of the motor from the initial value, if the jitter center of the first image corresponding to the first gain is outside the first image, increasing or decreasing the gain based on the first gain by a first preset step length.

In one possible implementation manner, the gain of the motor is increased or decreased from an initial value, and when the motor is set to a different gain, the image acquired by the camera module in the first shooting state on the first preset calibration board is correspondingly acquired, which specifically may include: acquiring a second image acquired by the camera module when the gain of the motor is set to be a second gain in the process of increasing or decreasing the gain of the motor from an initial value; if the dithering center of the second image is within the second image, increasing or decreasing a second preset step length on the basis of the second gain to obtain a third gain, and acquiring a third image acquired by the camera module; determining a target step length based on the moving distance between the dithering center of the second image and the dithering center of the third image and a second preset step length; and increasing or decreasing the target step length on the basis of the third gain, and acquiring a fourth image acquired by the camera module when the motor is set to the target step length.

In this embodiment, since the gains of the motors are changed in order of magnitude, after detecting that the center of shake of an image is moved within the image, the correlation between the center of shake and the gain change can be determined by the change in the center of shake of two images, and the change in the gains of the motors corresponding to the two images. Based on the varying correlation, a gain value of the motor, i.e., a target step size, to be adjusted to move the dither center of the image to the center of the image can then be determined. Therefore, after the fact that the shaking center enters the image is determined, the shaking center can be quickly moved to the image center, the frequency of collecting and analyzing the image is reduced, and the OIS calibration speed is improved.

In some possible embodiments, the first preset calibration plate includes a plurality of circular feature points that are periodically arranged and the same size. The plurality of circular characteristic points with the same size which are periodically arranged can improve the accuracy of OIS calibration.

In some possible implementations, the at least one feature point includes more than two feature points.

In some possible embodiments, after searching for the target image with the distance between the shake center and the image center satisfying the preset condition in the N images, the method further includes: acquiring a fifth image acquired by the camera module in a second shooting state on a first preset calibration plate; in the second shooting state, the shooting module vibrates and the optical anti-shake function of the shooting module is closed; acquiring a sixth image acquired by the camera module in a third shooting state on a first preset calibration plate; in the third shooting state, the shooting module is kept stable; the compression ratio is determined based on the blur amounts of the feature points in the target image, the fifth image, and the sixth image. Wherein the compression ratio is used to indicate the performance of the motor.

In the scheme, after a target image with the distance between the shake center and the image center meeting the preset condition is found, the compression ratio can be calculated by combining the fuzzy amount of the feature point with the minimum shake in the target image and the fuzzy amount of the same feature point when the optical shake prevention function of the image pickup module is closed. Because the motor in the target image has already reached a better level for the compensation of the external shake, the compression ratio is calculated by using the blurring amount of the image acquired by the camera module at the moment, and the precision of the compression ratio calculation can be improved. Meanwhile, in order to avoid the influence of other factors, the fuzzy quantity of the same characteristic point in the image acquired by the camera module in a stable state is combined when the compression ratio is calculated. The accuracy of the compression ratio calculation can also be improved.

In some possible embodiments, determining the compression ratio based on the blur amounts of the feature points in the target image, the fifth image, and the sixth image may include: obtaining corresponding fuzzy amounts of target feature points in a first preset calibration plate in a target image, a fifth image and a sixth image respectively; the compression ratio is calculated based on the corresponding blur amounts of the target feature points in the target image, the fifth image, and the sixth image.

In some possible embodiments, the compression ratio is calculated based on the corresponding blur amounts of the target feature point in the target image, the fifth image, and the sixth image, and in particular, the compression ratio may be calculated by the following formula: CR= -20Log10 ((OIS on-Still)/(OIS off-Still)); where CR represents the compression ratio, OIS on represents the amount of blur corresponding to the target feature point in the target image, OIS off represents the amount of blur corresponding to the target feature point in the fifth image, still represents the amount of blur corresponding to the target feature point in the sixth image.

In a second aspect, the present application provides a calibration method for optical anti-shake, the method comprising:

acquiring a calibration image acquired by the camera module on a second preset calibration plate; the second preset calibration plate comprises at least one characteristic point; acquiring a first position of a preset feature point in a second preset calibration plate in a calibration image and a distance between the first position and an image center of the calibration image; adjusting the stroke of a motor of the camera module based on the distance between the first position and the image center of the calibration image to enable the preset feature point to be located at the image center; acquiring M images acquired by the camera module in a third shooting state on a second preset calibration plate; the third shooting state comprises that the camera shooting module vibrates and the optical anti-shake function of the camera shooting module is started; when the optical anti-shake function of the camera shooting module is started and the camera shooting module is used for collecting images, the motor drives the lens of the camera shooting module to move so as to compensate the blurring caused by the vibration of the camera shooting module; m is a positive integer greater than or equal to 2; obtaining jitter conditions of preset feature points in M images; and determining a calibration gain value of the motor based on the jitter condition of the preset feature points.

In the scheme, a calibration plate comprising at least one characteristic point is used for carrying out optical anti-shake calibration on an image pickup module which carries out optical anti-shake processing in the X direction and the Y direction of the prism. After an image is acquired, the distance between the preset feature points and the center of the image is determined. And then, the stroke of the motor is changed based on the distance, and the preset characteristic point is adjusted to the center of the image, namely the center of the picture of the camera module. Therefore, the problem of low optical anti-shake calibration accuracy caused by the fact that the preset characteristic points are not located in the picture center of the camera module can be avoided.

In a third aspect, an electronic device is provided, comprising: a processor and a memory; the memory is configured to store computer-executable instructions that, when executed by the electronic device, cause the electronic device to perform the method of calibrating optical anti-shake according to any of the first aspects described above.

In a fourth aspect, a computer readable storage medium is provided, having instructions stored therein, which when run on a computer, cause the computer to perform the optical anti-shake calibration method according to any one of the first aspects above.

In a fifth aspect, a computer program product is provided comprising instructions which, when run on an electronic device, enable the electronic device to perform the optical anti-shake calibration method of any one of the first aspects above.

In a sixth aspect, there is provided an apparatus (e.g. the apparatus may be a system-on-a-chip) comprising a processor for supporting an electronic device to implement the functions referred to in the first aspect above. In one possible design, the apparatus further includes a memory for storing program instructions and data necessary for the electronic device. When the device is a chip system, the device can be formed by a chip, and can also comprise the chip and other discrete devices.

The technical effects caused by any one of the design manners of the third aspect to the sixth aspect may be referred to the technical effects caused by the different design manners of the first aspect and the second aspect, and are not described herein.

Drawings

FIG. 1 is a schematic diagram of an image collected by a camera module on a calibration board according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of a personal computer according to an embodiment of the present application;

fig. 3 is a schematic application scenario diagram of an optical anti-shake calibration method according to an embodiment of the present application;

FIG. 4 is a schematic flow chart of an optical anti-shake calibration method according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a first preset calibration plate according to an embodiment of the present application;

FIG. 6 is a schematic diagram of a first preset calibration plate according to an embodiment of the present application;

FIG. 7 is a schematic flow chart of an optical anti-shake calibration method according to an embodiment of the present application;

FIG. 8 is a schematic diagram of a filtered image according to an embodiment of the present application;

FIG. 9 is a schematic flow chart of an optical anti-shake calibration method according to an embodiment of the present application;

FIG. 10 is a schematic flow chart of an optical anti-shake calibration method according to an embodiment of the present application;

FIG. 11 is a schematic flow chart of an optical anti-shake calibration method according to an embodiment of the present application;

FIG. 12 is a schematic diagram of an image capturing module according to an embodiment of the present application for capturing an image of a second preset calibration plate;

fig. 13 is a schematic structural diagram of a chip system according to an embodiment of the present application.

Detailed Description

OIS compensates for imaging blur caused by camera shake during photographing by moving the lens group or the position of the photosensitive chip, thereby achieving the functions of damping and anti-shake, and enabling the photographed picture to be clear and stable. For the camera module with the OIS anti-shake function, in order to ensure the OIS anti-shake effect, the OIS function needs to be calibrated before the camera module is put into use.

In some embodiments, in the OIS anti-shake system, a motor is used to drive a lens in the camera module to move on a plane perpendicular to an optical axis, so as to offset as much as possible the influence of external vibration (such as hand shake) on the resolution of a picture during shooting. Specifically, when shooting, according to the acquired shake data, the motor can generate a reactive force, so that a light path influenced by shake is balanced, and the shake light can still fall at an original position, so that a more stable and clear imaging effect is obtained.

Because of the production differences of the motors, the sensitivity of different motors to the same shake data may be different. The offset of the lens movement controlled by the motor and the external jitter meet a certain relation, and the relation can be expressed by the gain of the motor. In the case where the shake data at the time of photographing is the same, if the gains of the motors are set to different values, the amounts of offsets by which the motors control the lens movement are different. In some embodiments, in order to obtain a better anti-shake effect, the motor is required to push the lens as far as possible to a place where the light can fall to the original position. Therefore, this position can be found by adjusting the gain of the motor, i.e., the gain of the motor that can obtain a good anti-shake effect, may be referred to as the optimal gain of the motor. The OIS calibration process, i.e. the process that involves finding the optimum gain value for the motor.

One calibration method commonly used in the related art is to use a single feature calibration plate to perform OIS calibration on a camera module, set a single feature in the center of the calibration plate, and perform OIS calibration on the camera module to be calibrated based on the captured image after using the camera module to be calibrated to capture the image captured by the calibration plate.

And after the optical anti-shake (OIS) function is started, anti-shake processing is performed on the prism in the X direction and the Y direction, such as the periscope type camera module. That is, if the OIS function is turned on, the motor of the camera module will perform shake compensation in the X direction and the Y direction of the prism according to the shake. When the periscope type camera module collects images, the paths of light need to be refracted by the prisms to reach the imaging device, so that if anti-shake processing is performed in the X direction and the Y direction of the prisms, compensation effects at different positions of the images are inconsistent. That is, the anti-shake effect may not be uniform at different positions of the captured image. Tests show that under the condition that the camera module shakes outside and the OIS function is started, the acquired image may generate image rotation. The rotation phenomenon means a phenomenon in which an image rotates with one center as an origin.

If the OIS calibration is performed by using the above method for the image capturing module that performs the anti-shake processing in the X-direction and the Y-direction on the prism, when the calibration plate is photographed by using different image capturing modules after the calibration plate is fixed in position, the position of the single feature in the image does not necessarily appear in the center of the image due to the problem of assembly. As shown in fig. 1, OIS calibration is performed using a calibration board 10, where a single cross feature (cross character) is disposed at the center of the calibration board 10, and when different image capturing modules capture images, the positions of the cross character in the image 11 captured by the image capturing modules may be 12, 13, 14 or 15, which is not necessarily the center of the image. It should be understood that in other embodiments, the features in the calibration plate used in OIS calibration may be feature points other than a single cross character, such as a single circular feature point, a single square feature point, or a single triangle feature point.

The anti-shake effect is usually determined by combining the shake amount of the feature points in the image collected by the camera module during OIS calibration, and in this case, the position targeted in the OIS calibration process is the position where the single feature point collected in the image is located. For periscope type camera modules, the position of a single feature point is not necessarily the center of a lens picture (image center) of the camera module when an image is acquired, and therefore the position of OIS calibration evaluation is not necessarily the center of the lens picture.

However, since a user captures an image using the image capturing module, the focus of the capturing is usually placed on the center of the image. Therefore, when the optical anti-shake calibration is performed on the image capturing module, it is generally necessary to evaluate the anti-shake effect of the center of the lens frame of the image capturing module. If the above method is used for OIS calibration of the lens of the type, the problem that the center of image evaluation is far from the 0 field of view of the center of the lens picture and the accuracy of OIS calibration is low easily occurs.

Based on the above, the application provides an optical anti-shake calibration method. In the method provided by the embodiment of the application, the first preset calibration plate adopted in the OIS calibration comprises at least one characteristic point. Acquiring N images acquired by the camera module on a first preset calibration plate in a first shooting state; wherein, different images are respectively acquired when the motors of the camera modules are set to different gains. And then, the jitter center of each image can be determined based on the jitter conditions of the characteristic points in each image acquired by the camera module. Then, a target image with the distance between the shaking center and the image center meeting the preset condition can be found in the N images, and the target gain correspondingly set by the motor when the camera shooting module collects the target image is determined to be the calibrated gain value of the motor of the camera shooting module. The preset condition is used for indicating that the distance between the dithering center of the image and the center of the image is minimum, and the distance is smaller than a first preset threshold value.

According to the method, when OIS calibration is carried out, the target image with the shake center and the image center meeting the preset condition is found, the gain value of the motor is determined based on the target image, and the position aimed by OIS calibration is ensured to be the image center or the position close to the image center, namely the position of the picture center of the camera module. Even if the image acquired under the condition of starting the OIS function has image rotation, the motor calibration gain value can optimize the OIS effect of the image center (namely the picture center of the camera module). Thereby improving the accuracy of OIS calibration.

In some embodiments, the first preset calibration board may include more than two feature points, so that any one or more feature points may be selected according to actual situations when OIS calibration is performed, and OIS effects are evaluated based on jitter situations of the one or more feature points. In an image having an image rotation problem, the shake center of the image may have the smallest amount of shake or no shake, and the amount of shake at other positions than the shake center is larger. Thus, the dither center of the image can be found based on analyzing the dither conditions of different feature points in the image. Then, searching a target image with the jitter center closest to the image center in N images acquired by the camera shooting module, and taking the target gain of the motor corresponding to the target image as a calibration gain value of the motor. The image center of the target image is a position close to the minimum jitter amount in the whole image, and is also a position with the best anti-jitter effect in the target image. The motor gain corresponding to the target image is a motor gain value which can make the anti-shake effect of the center of the lens picture (image center) reach the best, namely a motor calibration gain value which is required to be determined by OIS calibration.

Therefore, the position aimed by calibration can be ensured to be the position corresponding to the center of the lens picture (namely the center of the image), so that the accuracy of calibration is improved. And moreover, the OIS calibration can be completed by searching jitter centers of different images, so that the OIS calibration process can be completed quickly, the time required by OIS calibration is reduced, and the OIS calibration efficiency is improved.

From the above description, if the image capturing module performs the optical anti-shake processing in the X-direction and the Y-direction of the prism, the image captured by the image capturing module may still have an image rotation problem. In some embodiments, the above-described dither center, which may also be referred to as the image center of rotation, in an image that produces image rotation problems.

It should be noted that, the calibration method for optical anti-shake provided by the embodiment of the application can be applied to an independent test device, can be applied to a test module, or can be applied to an electronic device connected with the test device.

By way of example, in some embodiments, the electronic device may be a mobile phone, tablet, desktop, laptop, handheld computer, personal computer, notebook, ultra-mobile personal computer (UMPC), netbook, cellular phone, PDA (personal digital assistant, PDA), wearable device, augmented reality (augmented reality, AR), virtual Reality (VR) device, media player, television, etc., and embodiments of the present application are not limited in particular form to such devices.

Taking the above-mentioned electronic device as an example, the electronic device may be a personal computer 20, please refer to fig. 2, which is a schematic diagram of the structure of the personal computer 20 according to an embodiment of the present application. As shown in fig. 2, the personal computer 20 may include: processor 21, memory 22, display screen 23, wi-Fi device 24, bluetooth device 25, audio circuit 26, microphone 26A, speaker 26B, power system 27, peripheral interface 28, sensor module 29, data conversion module 30, etc. The components may communicate via one or more communication buses or signal lines (not shown in fig. 2). Those skilled in the art will appreciate that the hardware architecture shown in fig. 2 is not limiting of the personal computer 20, and that the personal computer 20 may include more or fewer components than shown, or may combine certain components, or a different arrangement of components.

Among them, the processor 21 is a control center of the personal computer 20, connects various parts of the personal computer 20 using various interfaces and lines, and performs various functions and processes of the personal computer 20 by running or executing application programs stored in the memory 22, and calling data and instructions stored in the memory 22. In some embodiments, the processor 21 may include one or more processing units; the processor 21 may also integrate an application processor and a modem processor; the application processor mainly processes an operating system, a user interface, an application program and the like, and the modem processor mainly processes wireless communication. It will be appreciated that the modem processor described above may not be integrated into the processor 21.

In other embodiments of the present application, the processor 21 may also include an AI chip. The learning and processing capabilities of the AI chip include image understanding capabilities, natural language understanding capabilities, voice recognition capabilities, and the like. The AI chip may enable better performance, longer endurance, and better security and privacy of the personal computer 20. For example, if the personal computer 20 processes data through the cloud, the result is returned after the data is uploaded, which is inefficient in the prior art. If the local side of the personal computer 20 has a strong AI learning capability, the personal computer 20 does not need to upload data to the cloud end and directly processes the data at the local side, so that the processing efficiency is improved and the safety and privacy of the data are improved.

The memory 22 is used to store application programs and data, and the processor 21 performs various functions and data processing of the personal computer 20 by running the application programs and data stored in the memory 22. The memory 22 mainly includes a memory program area and a memory data area, wherein the memory program area can store an operating system, at least one application program required by a function (such as a sound playing function, an image playing function, etc.); the storage data area may store data (such as audio data, video data, etc.) created according to the use of the personal computer 20. In addition, the memory 22 may include high-speed random access memory, and may also include nonvolatile memory, such as magnetic disk storage devices, flash memory devices, or other nonvolatile solid state memory devices, among others.

The memory 22 may store various operating systems. For example, the memory 22 may also store data related to calibration of embodiments of the present application, such as acquired images, motor gain, etc.

The display screen 23 is for displaying images, videos, and the like. The display screen may be a touch screen. In some embodiments, the personal computer 20 may include 1 or N displays 23, N being a positive integer greater than 1. The personal computer 20 realizes a display function by a GPU, a display screen 23, an application processor, and the like. The GPU is a microprocessor for image processing, and is connected to the display screen 23 and the application processor. The GPU is used to perform mathematical and geometric calculations for graphics rendering. Processor 21 may include one or more GPUs that execute program instructions to generate or change display information.

Wi-Fi means 24 for providing personal computer 20 with network access that complies with Wi-Fi related standard protocols. The personal computer 20 may access Wi-Fi access points via Wi-Fi device 24 to facilitate user email, web browsing, streaming media access, etc., which provides wireless broadband internet access to the user. The personal computer 20 may also establish a Wi-Fi connection through a Wi-Fi device and a Wi-Fi access point with a terminal device connected to the Wi-Fi access point for transmitting data to each other. In other embodiments, the Wi-Fi device 24 can also act as a Wi-Fi wireless access point, and can provide Wi-Fi network access to other computer devices.

Bluetooth means 25 for enabling data exchange between the personal computer 20 and other short-range electronic devices, such as terminals, smart watches, etc. The Bluetooth device in the embodiment of the application can be an integrated circuit or a Bluetooth chip and the like.

Audio circuitry 26, microphone 26A, speaker 26B may provide an audio interface between a user and personal computer 20. The audio circuit 26 may transmit the received electrical signal after audio data conversion to the speaker 26B, and the speaker 26B converts the electrical signal into a sound signal for output; on the other hand, the microphone 26A converts the collected sound signals into electrical signals, which are received by the audio circuit 26 and converted into audio data, which are transmitted to the terminal via the internet or Wi-Fi network or bluetooth, or which are output to the memory 22 for further processing.

The power supply system 27 is used to charge the various components of the personal computer 20. The power system 27 may include a battery and a power management module, where the battery may be logically connected to the processor 21 through a power management chip, so that functions of managing charging, discharging, and power consumption management may be implemented through the power system 27.

Peripheral interface 28 provides various interfaces for external input/output devices such as a keyboard, mouse, external display, external memory, user identification module card, etc. For example, the mouse is connected through a universal serial bus interface, so that the purpose of receiving relevant operations implemented by a user through the mouse is achieved. For another example, the expansion of the memory capability of the personal computer 20 is achieved by connecting an external memory interface to an external memory, such as a Micro SD card. Peripheral interface 28 may be used to couple the external input/output peripherals described above to processor 21 and memory 22.

The sensor module 29 may include at least one sensor. Such as light sensors, motion sensors, and other sensors. In particular, the light sensor may comprise an ambient light sensor. The ambient light sensor can adjust the brightness of the display screen 23 according to the brightness of the ambient light. As one type of motion sensor, an accelerometer sensor can detect the acceleration in all directions (typically three axes), and can detect the gravity and direction when stationary, and can be used for applications for recognizing the gesture of a personal computer (such as horizontal-vertical screen switching, related games, magnetometer gesture calibration), vibration recognition related functions (such as pedometer, knocking), and the like. Of course, the sensor module may also include any other feasible sensor, depending on the actual requirements.

The data conversion module 30 may include a digital-to-analog converter 30A and an analog-to-digital converter 30B. Among them, digital-to-analog converter (digital to analog converter, DAC), also called D/a converter. A digital-to-analog converter is a device that converts a digital signal into an analog signal. An analog-to-digital converter (analog to digitalconverter, ADC), also called a/D converter. An analog-to-digital converter is a device that converts an analog signal to a digital signal.

In some embodiments, the calibration method of optical anti-shake in the following embodiments may be performed in the personal computer 20 having the above-described hardware configuration.

Technical terms that may be involved in the embodiments of the present application are described below.

Periscopic lens is also called as 'internal zoom' lens, which means that optical zooming is completed inside the body.

The optical image stabilizer works on the principle that the gyroscope detects the jitter and performs displacement compensation. Namely, the gyroscope in the lens detects the tiny movement generated by the shake of the camera module, then the signal is transmitted to the central processing unit (central processing unit, CPU) for processing, and the CPU calculates the displacement to be compensated. And then controlling the motor to move the suspension lens in the camera module according to the displacement to be compensated so as to offset the tiny displacement generated by the shake, thereby effectively overcoming the image blurring generated by the vibration of the camera module.

OIS on indicates that the optical anti-shake function is on, OIS off indicates that the optical anti-shake function is off.

The gain of the motor, the offset of the motor control lens movement and the magnitude of external shake meet a certain relation, and the relation can be expressed by the gain of the motor.

The OIS calibration process is the optical anti-shake calibration process. In this process, the gain of the motor, i.e., the optimum gain value of the motor, at which a good anti-shake effect can be obtained can be determined.

In some embodiments, the OIS calibration process for the camera module to be calibrated may include: opening the optical anti-shake function of the camera shooting module, and adding vibration to the camera shooting module. And adjusting the gain of a motor of the camera module, and acquiring an image acquired by the camera module to a first preset calibration plate when the motor is set to be at each gain. And then analyzing images corresponding to gains of different motors to determine the calibrated gain value of the motors. Wherein the vibration may be a constant vibration, such as a 6 hertz (Hz), 3 degrees (°), 5Hz, 1 ° vibration. The first preset calibration plate comprises at least one characteristic point, and the first preset calibration plate is positioned in the shooting range of the shooting module to be calibrated.

In order to calibrate the OIS of the camera module, the anti-shake effect of the camera module when the OIS function is turned on needs to be evaluated. Therefore, during OIS calibration, external jitter (e.g., hand jitter) needs to be simulated. In the embodiment of the application, the vibration table drives the camera module to vibrate so as to simulate external shake.

Fig. 3 is a schematic application scenario diagram of an optical anti-shake calibration method according to an embodiment of the present application. In this embodiment, the above-described method is applied to the personal computer 30 connected to the test apparatus as an example. As shown in fig. 3, a personal computer 30 is connected to the test device 31 and the camera module 32, and the personal computer 30 may send instructions to the test device 31 to cause the test device 31 to perform corresponding operations based on the instructions. The personal computer 30 may also send instructions to the camera module 32 to control the adjustment of parameters of the devices in the camera module 32. Wherein the camera module 32 may be arranged on the test device 31. It should be appreciated that the vibration table 311 will drive the camera module 32 to vibrate when vibrating.

Illustratively, the test apparatus 31 includes a vibration table 311, and the test apparatus 31 may receive a first instruction from the personal computer 30, and in response to the first instruction, control the vibration table 311 to vibrate according to a preset vibration parameter. The preset vibration parameters may specifically include a vibration angle and a vibration frequency. It should be appreciated that the vibration table 311 of the test apparatus 31 may remain stationary while the personal computer 30 does not send the first instruction to the test apparatus 31.

Illustratively, the camera module 32 includes a motor 321 and a lens 322. The camera module 32 may receive a second instruction from the personal computer 30, and control the gain of the motor 321 to be adjusted to a specified value in response to the second instruction. After the optical anti-shake function of the camera module 32 is turned on, when the lens 322 of the camera module 32 collects images, if external shake is detected, the motor 321 will move according to the currently set gain value, so as to push the lens 322 to move in the opposite direction of shake, and offset the external shake as much as possible. Thereby obtaining a relatively stable and clear image.

It should be noted that, the personal computer 30 shown in fig. 3 is connected to the test device 31 and the camera module 32, and may control the test device 31 and the camera module 32 to perform corresponding operations. In other embodiments, the testing device 31 and the camera module 32 may be connected to different personal computers, and the respective personal computers control the testing device and the camera module. Wherein a connection and communication can be established between a personal computer connected to the test device 31 and a personal computer connected to the camera module 32.

In other embodiments, in the calibration process, the calibration may also be performed directly on a complete electronic device (such as a mobile phone), where the electronic device is provided with a camera module and a motor. The mobile phone is arranged on the testing equipment, and the mobile phone is driven to vibrate when the vibrating table in the testing equipment vibrates. It can be understood that when the mobile phone vibrates, the camera module in the mobile phone also vibrates. In this embodiment, the personal computer may also send instructions to the cell phone to control the cell phone to adjust parameters of the devices in the camera module 32.

The application provides an optical anti-shake calibration method which can be applied to a scene for calibrating the optical anti-shake function of part of camera modules, can calibrate the camera modules for anti-shake treatment in the X direction and the Y direction of a prism, and can avoid the problem of lower accuracy of OIS calibration caused by the image rotation problem.

The following describes in detail the calibration method of optical anti-shake provided in the embodiment of the present application with reference to the embodiment and the accompanying drawings. Fig. 4 is a schematic flow chart of an optical anti-shake calibration method according to an embodiment of the application. In this embodiment, the calibration method of optical anti-shake is applied to a personal computer connected to a test apparatus as an example. The method comprises S401-S410, wherein:

s401, the personal computer sends a first instruction to the testing equipment.

The first instruction is used for indicating the test equipment to execute corresponding operation.

In some embodiments, the test apparatus comprises a vibrating table. For example, the first instruction may be for instructing the vibration table to vibrate at a preset vibration parameter; the first instruction carries preset vibration parameters. After receiving the first instruction, the test device may parse the first instruction to obtain a preset vibration parameter.

In some embodiments, the preset vibration parameters may include a vibration angle and a vibration frequency. The vibration angle is, for example, 3 °, and the vibration frequency is 6Hz. After the test equipment obtains preset vibration parameters, the vibration table is controlled to vibrate based on the vibration angle and the vibration frequency. In other embodiments, the vibration angle and the vibration frequency in the preset vibration parameter may be set to other values, which are not limited in the embodiment of the present application.

In other embodiments, the preset vibration parameters may further include a vibration time for indicating the vibration table. Wherein the vibration time may include a start time and an end time of the vibration; or the vibration time may also include the duration of the vibration; alternatively, the vibration time may also be used to indicate the period of vibration, and so on. After the test equipment obtains preset vibration parameters, the vibration table is controlled to vibrate based on vibration time in the test equipment.

In addition to the first instructions for instructing the vibration-related parameters described above, in other embodiments the first instructions may also be used to instruct the test device to adjust other parameters. For example, the first instructions may be used to indicate a location, an altitude, etc. parameter of the test equipment setting.

It should be understood that S401 may also be denoted as the test device receiving a first instruction from a personal computer.

S402, the test equipment responds to the first instruction and controls the vibration table to vibrate according to preset vibration parameters.

In some embodiments, the test apparatus controls the vibration table to vibrate at a preset vibration parameter in response to the first instruction. As can be seen from the above description of fig. 3, the vibration table drives the camera module arranged on the vibration table to vibrate together in a vibrating state.

S403, the personal computer sends a second instruction to the camera module.

The camera module has an optical anti-shake (OIS) function. In the embodiment of the application, the camera shooting module comprises the motor and the prism, and after the optical anti-shake function is started, the camera shooting module can compensate the blurring caused by external shake by pushing the prism to move in the X direction and the Y direction by the motor. The camera module may be, for example, a periscope camera module. It should be understood that the above-mentioned image capturing module is only an example, and in other embodiments, the image capturing module may be another image capturing module that implements the optical anti-shake process through a prism.

As can be seen from the above description of fig. 3, the camera module may be arranged on the vibration table during calibration. Wherein the vibrating table can vibrate or remain stationary under control. Under the vibration state of the vibration table, the camera shooting module can be affected by the vibration of the vibration table to vibrate. Under the state of keeping static, the vibration table is regarded as that the camera module is still, namely the camera module is not influenced by external shake.

In some embodiments, the second instruction may include a preset value for indicating to adjust the gain of the motor of the camera module to the preset value. Wherein the preset values may include one or more.

When the second instruction includes carrying a preset value, the personal computer can send the second instruction to the camera module for a plurality of times, and the different second instructions include different preset values, so that the camera module adjusts the gain of the motor to different values. In some embodiments, the intervals between the preset values corresponding to the adjacent two second instructions sent by the personal computer may be the same.

In some embodiments, the preset values carried in the second instruction sent by the personal computer to the camera module according to the time sequence may be arranged according to the order of magnitude. For example, when the personal computer first sends the second instruction to the camera module, the preset value carried by the second instruction is 0. When the personal computer sends a second instruction to the camera module for the second time, the preset value carried by the second instruction can be 0.2. When the personal computer sends a second instruction to the camera module for the third time, the preset value carried by the second instruction can be 0.5; and so on.

Further, the preset value carried in the second instruction sent by the personal computer to the camera module according to the time sequence may be increased or decreased from the initial value according to a preset step. Taking the preset step length of 0.1 as an example, when the personal computer sends the second instruction to the camera module, sequentially increasing (or decreasing) the preset value carried in the last second instruction by the preset step length to obtain the preset value corresponding to the second instruction. The initial value and the preset step length can be set according to actual conditions. In some embodiments, the initial value may be set to 0, with the preset value increasing from 0. Alternatively, in other embodiments, the initial value may be set to a value greater than 0, with the preset value decreasing from the initial value.

For example, when the personal computer first sends the second instruction to the camera module, the preset value carried by the second instruction is 0. When the personal computer sends a second instruction to the camera module for the second time, the preset value carried by the second instruction can be 0.1. When the personal computer sends a second instruction to the camera module for the third time, the preset value carried by the second instruction can be 0.2; and so on. It should be understood that the above-described preset step sizes are only examples, and in other embodiments, the preset step sizes may be set to other values.

In some embodiments, the preset step size may be adjusted according to the actual situation. For example, when the personal computer sends the second instruction to the camera module within a period of time, the preset value is sequentially increased by a preset step length of 0.1. When the personal computer sends a second instruction to the camera module in another period of time, the preset numerical value is sequentially increased by the preset step length of 0.5.

When the second instruction carries a plurality of preset values, the personal computer sends the second instruction to the camera module once, and the camera module can be instructed to control the gain adjustment of the motor to be different preset values based on the second instruction respectively.

In other embodiments, the second instruction may also include a gain adjustment rule. In some embodiments, the second instruction is to instruct the gain of the motor to increase from an initial value by a preset step size. The preset step size is set according to the actual situation, which is not limited in the embodiment of the present application.

Before the imaging module to be calibrated performs OIS calibration, the OIS function of the imaging module needs to be started. In some embodiments, the camera module may turn on the OIS function in response to a second instruction, which may also be used to instruct the camera module to turn on the OIS function in this embodiment. In other embodiments, the OIS function of the camera module may also be manually turned on; that is, before S403, the OIS function of the camera module to be calibrated is manually turned on by the relevant personnel.

It should be understood that S403 may also be represented as the camera module receiving a second instruction from the personal computer.

S404, the camera module responds to the second instruction, and the gain of the motor of the camera module is controlled to be adjusted to be a preset value.

As can be seen from the above description of the embodiments, the second instruction may carry a predetermined value. In this embodiment, when the camera module receives the second instruction sent by the personal computer, the motor of the camera module is controlled to adjust to a preset value in the second instruction. When a new second instruction sent by the personal computer is received, controlling a motor of the camera module to adjust to a preset value corresponding to the new second instruction. After receiving the second instruction, the camera module determines that the preset value corresponding to the second instruction is 0.1, adjusts the motor to 0.1 in response to the second instruction, and then performs image acquisition. When the camera module receives a new second instruction, the preset value corresponding to the new second instruction is 0.2, the gain of the motor is adjusted to be 0.2 in response to the new second instruction, and then image acquisition is carried out; and so on.

In other embodiments, the second instruction may carry a plurality of preset values. In this embodiment, after receiving the second instruction, the camera module analyzes and obtains a plurality of preset values corresponding to the second instruction. And responding to the second instruction, firstly adjusting the gain of the motor to one of preset values by the camera shooting module, and then carrying out image acquisition. Then, the gain of the motor is adjusted to be another preset value, and image acquisition is carried out; and so on. When the second instruction carries the adjustment rule of the gain, the camera module can adjust the gain of the motor to one value each time according to the adjustment rule and acquire an image, then adjust the gain to the next value, and acquire a new image; and so on.

S405, the camera module collects corresponding images of the first preset calibration plate.

Before the OIS calibration is carried out on the camera module to be calibrated, the optimal optical anti-shake effect of the camera module can be achieved when the motor gain of the camera module is set to be a value. Therefore, in the embodiment of the application, when the gains of the motors are set to different values, the optical anti-shake effect of the image acquired by the image pickup module can be evaluated respectively. When the optical anti-shake effect of the image acquired by the camera module is optimal, the corresponding value of the motor gain is the optimal gain value of the motor. In the image with the image rotation phenomenon, the optical anti-shake effects of different positions in the image are inconsistent, so that in order to adapt to the requirements of users, the value of the corresponding motor gain can be determined as the optimal gain value of the motor when the optical anti-shake effect of the position of the image center of the image acquired by the image pickup module is optimal.

In some embodiments, the first preset calibration plate includes at least one feature point. The first preset calibration plate may include one feature point, or may include more than two feature points. As can be seen from the above description, the first preset calibration plate is within the shooting range of the camera module, so that the camera module can collect the images of the feature points in the first preset calibration plate from the images collected by the first preset calibration plate.

Further, in an embodiment, the shape of the feature points included in the first preset calibration plate may be any shape, such as a square, a triangle, a cross, or a circle.

When the first preset calibration plate includes more than two feature points, in some embodiments, the plurality of feature points in the first preset calibration plate may be periodically arranged, the shape and size of the plurality of feature points are the same, and the interval between adjacent feature points is the same. The interval between adjacent feature points, and the shape and size of a single feature point can be set according to practical situations.

Taking the shape of the feature point as a circle as an example, fig. 5 is a schematic diagram of a first preset calibration plate in some embodiments. Wherein a plurality of circular feature points with the same size are periodically arranged in a first preset calibration plate; the intervals between adjacent circular feature points are the same. In other embodiments, the color of the feature point in the first preset calibration plate may be any color.

In some embodiments, the first preset calibration plate includes a plurality of circular feature points. As can be seen from the above description, the image capturing module may have a rotation problem after the OIS function is turned on. If the feature point is shaped like a square, triangle, etc., then at the position where the center of shake (i.e., like the center of rotation) is located, the center position of the feature point may not move with external shake (vibration), but there may be a movement caused by rotation, resulting in blurring. As shown in fig. 6, taking the example that the position corresponding to 601 shown in the figure is the shake center of the image, the square feature point 602 still has the blur generated by rotating with the shake center as the origin, and the blur amount generated by rotating other feature points (such as the feature point 603 and the feature point 604) except the shake center with the shake center as the origin is relatively larger than the blur amount of the feature point 602. The blurring amount of the feature point is used to represent the blurring degree of the feature point, and the larger the blurring amount is, the larger the blurring degree of the feature point is represented, and the larger the shake of the feature point can be reflected.

If the feature point is circular, even if the circular feature point rotates at the position of the image rotation center, the smaller point of the circular feature point in the picture can be found relatively easily, so that the position of the shake center can be conveniently located.

In some embodiments, the interval between adjacent feature points in the first preset calibration plate and the size of a single feature point may be set in combination with parameters of the camera module to be calibrated. Illustratively, the parameters of the camera module may include an optical front focal length (Front Focal Length, EFL), a Field of View (FOV), and a vibration angle of the camera module.

As a possible implementation, the feature points in the calibration plate may be adjusted in combination with the parameters of the camera module. In some embodiments, to reduce the test error, when the FOV of the camera module to be calibrated is increased, the diameter of the circular feature point may be relatively increased when the first preset calibration plate is set. The larger the FOV is, the wider the coverage area can be covered when the camera module is used for collecting images, so that the analysis of the collected images is facilitated when the diameter of the circular feature points is larger. Conversely, if the FOV is smaller, the diameter of the circular feature point in the first preset calibration plate may be set smaller.

In other embodiments, when the vibration angle of the camera module is increased, the diameter of the circular feature point may be relatively reduced when the first preset calibration plate is provided; conversely, the smaller the vibration angle, the diameter of the circular feature point provided in the first preset calibration plate may be relatively increased. When the vibration angle is increased, in the image acquired by the camera module, the motion tracks of adjacent feature points may overlap, and the fuzzy parts may overlap. This is disadvantageous for analyzing the dither effect based on the circular feature points in the image. Therefore, in order to enable the camera module to acquire the motion trail of more circular feature points, the diameter of the feature points can be reduced, so that the problem that the motion trail of different feature points is overlapped due to too large vibration angle is solved, and the accuracy of OIS calibration is improved.

In some embodiments, the number of images acquired by the camera module at different motor gains is denoted as N. As can be seen from the description of the above embodiments, N images are acquired when the motors of the camera module are set to different gains. The value of N may be set in advance, or may be determined after the personal computer analyzes the optical anti-shake effect according to the image collected by the camera module.

As can be seen from the above description of the embodiments, the second instruction may only carry a preset value. In this embodiment, after receiving the second instructions, the camera module may control the gain adjustment of the motor to a preset value corresponding to each second instruction, and collect the image of the first preset calibration board after the gain adjustment of the motor.

In other embodiments, the second instruction may carry a plurality of preset values. In this embodiment, after receiving the second instruction, the camera module may respectively control the gains of the motors to be adjusted to different preset values, and collect images of the first preset calibration plate when the motors are set to different gains. The preset number carried by the second instruction comprises N.

In other embodiments, the second instruction may carry a gain adjustment rule. In this embodiment, the camera module may adjust the gain of the motor according to the adjustment rule, and collect an image of the first preset calibration plate when the motor is set to the gain. In some embodiments, the camera module accumulates N images.

It should be understood that S404 and S405 described above are operations performed by the camera module after receiving the second instruction. If the second instruction carries a preset value, the personal computer sends the second instruction to the camera module once, and the camera module sequentially executes S404 and S405.

If the second instruction carries a plurality of preset values, the personal computer sends the second instruction to the camera module once, and in S404, the camera module may perform S405 after adjusting the gain of the motor to one of the preset values in response to the second instruction, that is, collect an image for the first preset calibration plate. Then returning to S404, the camera module adjusts the gain of the motor to another preset value, and then S405 is executed to collect a new image for the first preset calibration board. And so on until all preset values in the second instruction are traversed.

Similarly, if the second instruction carries a rule for adjusting the gain of the motor, when S404 is executed for the first time, the camera module may set the gain of the motor to an initial value in response to the second instruction, and then S405 is executed to acquire an image of the first preset calibration board. Then returning to S404, the camera module adjusts the gain of the motor based on the adjustment rule in the second instruction, and then S405 is executed to acquire a new image for the first preset calibration plate; and so on.

The camera module is used for collecting images of the first preset calibration plate and can be manually operated; for example, the related personnel manually trigger the image acquisition operation of the camera module. Or, the camera module may also automatically perform the image capturing operation on the first preset calibration board after the gain of the motor is adjusted to a preset value in response to the second instruction.

It should be appreciated that, in an embodiment in which the camera module automatically performs the image capturing operation, the second instruction is further configured to instruct the camera module to capture an image of the first preset calibration plate after the gain of the motor is adjusted to a preset value. In this embodiment, the camera module may control the camera module to acquire an image of the first preset calibration plate after controlling the gain of the adjustment motor to a preset value in response to the second instruction.

When the second instruction comprises a plurality of preset values, the camera module respectively acquires an image of the first preset calibration plate when the control motor is set to different preset values. Also, in this embodiment, the image capturing module captures an image of the first preset calibration board, and may be manually operated or automatically performed after the gain of the motor is adjusted to a different preset value.

As can be seen from the above-mentioned steps S401-S404, when the camera module is executing step S405 to collect images, the camera module is in a vibration state, and an optical anti-shake (OIS) function of the camera module is turned on. In some embodiments, this shooting state is noted as a first shooting state.

S406, the camera module sends the image to the personal computer.

As can be seen from the above description of the embodiment, the second instruction may carry a predetermined value. In this embodiment, after the image capturing module executes S405, the image capturing module may send an image acquired this time to the personal computer. Then, if the camera module receives a new second instruction sent by the personal computer, S404-S406 are sequentially executed in response to the new second instruction; and so on.

In other embodiments, the second instruction may carry a plurality of preset values, or the second instruction may carry a rule for adjusting the motor gain. In some embodiments, when the camera module performs S404 and S405, the gain of the motor is adjusted to one of the preset values, and after the image is acquired by the first preset calibration board, S406 may be performed first, that is, the acquired image is sent to the personal computer. In other embodiments, when implementing the above S404 and S405, the camera module may collect images of the first preset calibration plate when the motors are respectively adjusted to different preset values, that is, after obtaining the images corresponding to the different motor gains, S406 is executed. Specifically, S406 includes: the camera module sends a plurality of images acquired when the motor is set to different gain values to the personal computer.

In other embodiments, where the second instruction carries a plurality of preset values, or where the second instruction carries a rule for adjusting the motor gain, the above S406 may also set a preset number. When the number of images collected by the camera module reaches the preset number, the camera module executes S406. For example, after each acquisition of 5 images, the camera module sends the 5 images to the personal computer, then continues to acquire new 5 images, and then sends the new 5 images to the personal computer; and so on.

It should be understood that S406 is also indicated as receiving, by the personal computer, an image sent by the camera module.

S407, the personal computer acquires the jitter condition of the characteristic points in the image.

In some embodiments, the first preset calibration plate includes one feature point. In this embodiment, S407 described above specifically includes a jitter condition in which the feature point is acquired.

In other embodiments, the first preset calibration plate includes a plurality of feature points. In this embodiment, the step S407 specifically includes obtaining jitter of one or more feature points in the first preset calibration plate.

S408, the personal computer determines the dithering center of the image according to the dithering condition of the characteristic points in the image.

The jitter center is used for indicating the position with minimum jitter in the image. As can be seen from the above description of the embodiments, after the OIS function of the imaging module performing OIS processing in the X-direction and the Y-direction of the prism is turned on, the image acquired by the imaging module may have a rotation problem when the outside world is in shake. The rotation indicates that the image rotates about an origin. Therefore, according to the images acquired in S401 to S405 described above, there may be a problem of image rotation. That is, there may be an origin of rotation of the image in each image acquired by the camera module, and in the embodiment of the present application, the origin is referred to as a shake center. It will be appreciated that the location of the center of jitter is the location in the image where jitter is minimal. It should be appreciated that in other embodiments, the wobble center may also be named other names such as spin center.

In some embodiments, the first preset calibration plate includes one feature point. In this embodiment, analysis is performed based on the shake situation of the feature point, and the position of the shake center of the image is determined.

In other embodiments, the image capturing module is an image acquired by a first preset calibration board including a plurality of feature points, so in the embodiment of the present application, a shake center may be determined by combining shake conditions of each feature point in the image.

In the same image, a feature point near the position with larger jitter will have larger blurring amount; in contrast, the blurring amount of the feature points near the position where the shake is small. Thus, in some embodiments, after the image acquired by the camera module is acquired, the center of shake of the image may be determined by determining a position in the image where the amount of blur is minimal.

In other embodiments, after the original image collected by the camera module is processed to a certain extent, the feature points and the blurred portions of the feature points are converted into feature objects, and then the size of the feature objects is determined to analyze the shake situation of the feature points. Since the feature object includes the feature point and the blurred portion of the feature point, the feature object corresponding to the feature point whose blur amount is larger. Conversely, the feature points with smaller blur amounts correspond to smaller feature objects. Thus, the step S408 may specifically include: processing the image, and converting a feature point in the image and the fuzzy quantity corresponding to the feature point into a feature object; and determining the jitter center of the corresponding image based on the size of the feature object in the image obtained after the filtering process.

In some embodiments, as shown in FIG. 7, the step S408 includes steps S701-S703, wherein:

s701, performing filtering processing on the image to obtain a filtered image.

In some embodiments, the step S701 may specifically include: and carrying out binarization processing on the image to obtain a binarized image, namely the filtered image. Image binarization (Image Binarization) is a process of setting the gray value of a pixel point on an image to 0 or 255, that is, making the whole image exhibit a remarkable black-and-white effect.

In some embodiments, at least one feature object corresponding to the at least one feature point is included in the post-filter processed image, and each feature object includes a respective feature point and a blurred portion of the respective feature point. The position of the dithering center in the image corresponding to each filtered image can be determined by analyzing the size of the feature object in each filtered image.

After the original image acquired by the camera module is subjected to binarization processing, the feature points and the fuzzy parts corresponding to the feature points can be converted into an integral feature object, and then the fuzzy quantity corresponding to the feature points can be judged according to the size of the feature object. The feature point with the smallest blurring amount can then be found by the size of the feature object. Finally, the position of the dithering center of the corresponding image can be determined based on the position where the blurring amount is minimum.

In other embodiments, the filtering process may be implemented in other manners in S701, so long as it is ensured that, in the image obtained by the filtering process, the feature points in the original image and the blurred portions corresponding to the feature points may be converted into an integral feature object.

S702, searching the minimum feature object in at least one feature object in the filtered image.

As is apparent from the description of the above embodiments, the feature object in the filtered image represents the feature point and the blurred portion corresponding to the feature point. The larger the shake amount is, the larger the motion track of the feature points is, the more blurred parts are in the acquired image, and the larger the feature objects in the corresponding filtered image are. Conversely, the smaller the amount of shake, the smaller the motion trajectory of the feature points, the fewer the blurred portions in the acquired image, and the smaller the feature objects in the corresponding filtered image. The feature point corresponding to the minimum feature object is the feature point with the minimum jitter amount in the image, and is also the feature point with the minimum blur amount. Thus, from the minimum feature object found in the filtered image, the position of the dither center of the corresponding image may be determined based on the minimum feature object.

In some embodiments, S702 may specifically search for the smallest feature object by comparing the sizes of the feature objects in the same filtered image. For example, if a certain feature object a is found in the filtered image, and the size of other surrounding feature objects is greater than or equal to the size of the feature object a for the feature object a, it may be determined that the feature object a is the smallest feature object. The size of the feature object may specifically be a length or an area of the feature object.

If the personal computer acquires N images and then determines shake centers for the N images, the step S702 may specifically include: and searching the minimum feature object in at least one feature object in each of the N filtered images.

S703, determining the position of the jitter center in the image corresponding to the filtered image based on the minimum feature object.

In images corresponding to different motor gains, the positions of the dither centers of the images may be different. In some embodiments, the dither center of the image may be outside the image, or the dither center of the image may be inside the image.

In some embodiments, the step S703 may specifically include: and in the target filtered image, if the minimum feature object is at the edge of the target filtered image and the size of the minimum feature object exceeds a second preset threshold, determining that the jitter center is outside the image corresponding to the target filtered image.

Wherein the target filtered image is any one of the N filtered images.

Since the center of shake of an image is a position where shake (blur amount) is minimum, if the center of shake is within the image, the blur amount of a feature point near the position where the center of shake is located is small, and at this time the feature point and the feature object corresponding to the feature point should be close in size. Thus, in some embodiments, the size of the feature object may be determined by setting a second preset threshold to determine whether the dither center of the image is within the image. The second preset threshold is used for measuring the size of the feature object. The second preset threshold value can be set according to the size of the feature points in the image acquired by the first preset calibration plate when the camera module does not shake (vibrate). For example, the second preset threshold may be set to 1.2 times or other times the size of the feature points in the image captured by the camera module without shake.

If the size of the smallest feature object found in the target filtered image is at the edge of the target filtered image and the size of the smallest feature object exceeds the second preset threshold, then the jitter center of the image corresponding to the target filtered image may be considered not to be present within the image corresponding to the target filtered image. In some embodiments, since the OIS calibration aims to find a location where the dither center is as close as possible to the image center, it may not be necessary to determine a specific location of the dither center of the image if it is determined that the dither center is not within the image.

In other embodiments, if the found minimum feature object is not at the edge of the target filtered image or the size of the minimum feature object in the target filtered image does not exceed the second preset threshold, the position of the dither center is determined based on the position of the minimum feature object in the target filtered image.

As is apparent from the description of the above embodiments, if the minimum feature object appears at the edge of the filtered image and the size exceeds the second preset threshold, it is determined that the dither center is out of the image corresponding to the filtered image. Then, conversely, if the minimum feature object is at an edge of the filtered image but the size of the minimum feature object does not exceed the second preset threshold, or the minimum feature object is not at an edge of the filtered image, then it may be determined that the dither center is now within the image corresponding to the filtered image. Then, the position of the jitter center is determined based on the position of the minimum feature object.

In some embodiments, the first preset calibration plate includes a plurality of feature points, and the feature points are periodically arranged, and there may be a certain interval between the feature points. In the partial image, the position of the shake center may be exactly at the center position of a certain feature point (feature object). At this time, the center position corresponding to the smallest feature object in the image may be directly acquired. In some embodiments, the determining the location of the jitter center based on the location of the minimum feature object in the target filtered image may specifically include: if the minimum feature object includes one feature object, determining the position of the center of the minimum feature object as the position of the jitter center.

In another part of the image, the dither center may be located at a position in the interval between the feature points. There may be multiple feature objects of the same size in the image in this embodiment. At this time, the position of the dither center of the image may be fitted based on the positions of the plurality of minimum feature objects. In some embodiments, the determining the location of the jitter center based on the location of the minimum feature object in the target filtered image may specifically include: if the minimum feature object includes more than two feature objects, the position of the jitter center is fitted based on the position of the minimum feature object.

By way of example, if 4 minimum feature objects of the same size are included in the filtered image, the position of the dither center may be determined as the center position of the region composed of the 4 minimum feature objects. In other embodiments, the position of the dither center of the fitted image may be implemented in any other manner based on the positions of the two or more minimum feature objects, which is not limited in the present application.

In the technical scheme provided by the embodiment of the application, the positions of the shake centers are searched by combining the number of the minimum feature objects, so that the positions of the shake centers can be quickly and effectively searched.

A, b, and c in fig. 8 are schematic diagrams of filtered images in some embodiments. Where 801, 802 and 803 respectively represent different feature objects. As shown in a of fig. 8, the personal computer may find that the smallest feature object in the filtered image is at an image edge, and if the size of the smallest feature object exceeds a second preset threshold, it is determined that the jitter center is outside the image corresponding to the target filtered image, and for example, the jitter center of a of fig. 8 may be at a position shown in 801. As shown in b in fig. 8, when the smallest feature object in the filtered image is found not to be at the edge of the filtered image, the dither center is determined to be within the image. The location of the dither center may then be determined based on the smallest feature object in b in fig. 8 (as shown at 802). In other embodiments, it may also be determined that the center of shake of the image is within the image when the minimum feature object is found to be at the edge of the image but the size of the minimum feature object (as shown in 803) does not exceed the second preset threshold. As shown in c of fig. 8, the smallest feature object in the filtered image is at the center of the image, which means that the dither center of the corresponding image of the filtered image is at the center of the image.

In the technical scheme provided by the embodiment of the application, the second preset threshold is set to distinguish whether the shaking center is within the image, and when the shaking center is determined to be outside the image, the gain of the motor is required to be continuously adjusted to enable the shaking center to move into the image. After the jitter center is determined to be within the image, the motor gain is adjusted so that the jitter center of the image can be moved to the image center. In this way, it may be convenient to determine an optimal gain value for the motor. Because the original image acquired by the camera module is subjected to filtering processing, the jitter center position can be determined directly by comparing the sizes of the characteristic objects. The fuzzy quantity of the characteristic points does not need to be calculated, the calculated quantity in the calibration process can be reduced, and the efficiency of OIS calibration is improved.

S409, the personal computer determines a target image in which the distance between the dithering center and the image center meets a preset condition.

In some embodiments, the preset condition is for indicating that a distance between a dither center of the image and a center of the image is the smallest in the acquired different images, and the distance is less than a first preset threshold. It will be appreciated that due to the production differences of the motors, it may occur that the dither centre cannot be brought into perfect register with the image centre, whatever the gain of the motor is adjusted. Therefore, in the embodiment of the application, as long as the distance between the shake center and the image center is found to be smaller than a certain value and is the smallest distance among the distances between the shake center and the image center in all the images, the motor gain corresponding to the image can be determined as the optimal gain value of the motor. In the embodiment of the application, an image satisfying a preset condition is recorded as a target image.

In some embodiments, the personal computer may perform S408 on the N images after acquiring the N images acquired by the camera module, that is, determine a shake center of each image. In this embodiment, the step S409 may specifically include: the personal computer searches the N images for a target image of which the distance between the dithering center and the image center meets a preset condition.

Further, the personal computer searches for a target image in the N images, where a distance between a shake center and an image center satisfies a preset condition, and specifically may include: the personal computer judges whether the distance between the dithering center and the image center of each image satisfies a preset condition.

In other embodiments, the personal computer may perform S407 and S408 after each image acquired by the camera module is acquired, and find the shake center of the image. In this embodiment, as shown in fig. 9, S409 may specifically include S901 and S902:

s901, the personal computer judges whether the distance between the dithering center of the current image and the image center meets the preset condition.

In this embodiment, the preset condition is used to indicate that the distance between the center of shake of the current image and the center of the image is the smallest among all the images that have been acquired, and the distance is smaller than the first preset threshold. And if the distance between the dithering center of the current image and the image center meets the preset condition, the current image is indicated to be the target image.

S902. the personal computer determines the current image as the target image.

In other embodiments, when the second instruction carries a rule for adjusting the gain of the motor, and when the gain of the camera module controlled motor is adjusted to different preset values according to the order of magnitude, in embodiments in which S407 is performed after the personal computer acquires each image sent by the camera module, if it is determined in S409 that the distance between the center of shake of the current image and the center of image meets the preset condition, the calibration gain value of the motor may be determined directly based on the current image. That is, if the distance between the center of shake of the current image and the center of the image satisfies the preset condition, the camera module may not need to collect a new image again.

In some embodiments, after determining that the distance between the center of shake of the current image and the center of the image satisfies the preset condition, the method further includes: the personal computer can stop acquiring the image acquired by the camera module, and the camera module can acquire the image without setting other motor gain values.

In an embodiment in which the second instruction includes a predetermined value, the personal computer may stop sending the second instruction to the camera module. In an embodiment in which the second instruction includes a plurality of preset values or the second instruction includes a regulation rule of the motor gain, the personal computer may transmit a third instruction to the camera module after determining in S409 that the distance between the center of shake of the current image and the center of the image satisfies the preset condition. The third instruction may be used to instruct the camera module to stop adjusting the gain of the motor and stop capturing the image of the first preset calibration plate.

It should be understood that, in the above example, after S901, if it is determined that the distance between the center of shake of the current image and the center of image does not meet the preset condition, S403 may be returned, S403-S408 may be sequentially performed, a new image may be re-acquired, and whether the preset condition is met may be analyzed.

In the technical scheme provided by the embodiment of the application, if the gain of the motor is adjusted according to the order of magnitude in the calibration process of the camera module, the camera module can be controlled to stop acquiring a new image when the shake center and the image center of one image are found to meet the preset condition. In this way, unnecessary image acquisition can be reduced. Meanwhile, the personal computer does not need to search the shake center for the later collected image and determine the distance between the shake center and the image center, so that the time for OIS calibration can be reduced, and the efficiency of OIS calibration can be improved.

S410, the personal computer acquires a target gain corresponding to the motor when the target image is acquired, and the target gain is determined to be a calibrated gain value of the motor.

As is apparent from the description of the above embodiments, if the distance between the center of shake and the center of image is found to satisfy the preset condition, that is, the anti-shake effect indicating the center of image or the position closer to the center of image in this image is the best in the entire image. Therefore, the gain (target gain) of the motor corresponding to the image can be determined as the calibration gain value of the motor, so that the best optical anti-shake effect of the center of the image (the center of the lens picture) is ensured when the motor is set as the calibration gain.

In the technical scheme provided by the embodiment of the application, the image acquired by the camera shooting module at different motor gains is analyzed, the position of the shaking center is searched in each image, and the target image is searched according to whether the distance between the shaking center and the image center is smaller than a certain value or not and the distance is the smallest in N images. Then, a gain value of the motor used to acquire the target image is determined as a calibrated gain value of the motor. Therefore, the position aimed by the OIS calibration can be ensured to be the image center or the position close to the image center as far as possible, namely the position of the picture center of the camera module is positioned, so that the position of the OIS calibration is close to the image center as far as possible, and the OIS calibration accuracy is improved. Meanwhile, the OIS calibration can be completed only by searching the shake centers of different images and determining that the shake centers are close to the image center, so that the OIS calibration process can be completed quickly, the time required by OIS calibration is reduced, and the OIS calibration efficiency is improved.

As can be seen from the description of the above embodiment, when the personal computer sends the second instruction to the camera module in S403, the preset value may be incremented or decremented according to the preset step. Taking the example that the second instruction carries a preset value, the personal computer controls the preset value to increment or decrement according to a preset step length when sending the second instruction to the camera module.

Meanwhile, as can be seen from the description of fig. 8, when the camera module sets the gain of the motor to different values, the jitter center of the image may be located outside or inside the image. In this embodiment, the preset value is incremented from 0. In combination with the flow shown in fig. 9, the personal computer sends a second instruction to the camera module once, receives the image collected by the camera module and analyzes: if the distance between the image center of the current image and the dither center does not satisfy the preset condition. And then the personal computer sends a new second instruction to the camera module, and receives a new image sent by the camera module for analysis.

Because the specific position of the shake center cannot be determined when the shake center is outside the image, when the personal computer sends a second instruction to the camera module for the first time, the preset value can be increased by a first preset step length. In the process of increasing the preset value (the gain of the motor), the dithering center in the image acquired by the camera module will move along with the dithering center. When the dither center appears within the image, a specific position of the dither center can be determined. The first preset step length can be set according to actual conditions.

After the center of shake starts to appear within the image, the correlation between the gain value of the motor and the variation of the center of shake, or the sensitivity, can be determined in conjunction with the moving distance of the position of the center of shake in the two images and the difference in the gains of the motors to which the two images correspond, respectively. And then controlling and adjusting the gain value of the motor based on the determined change association relation to enable the dithering center of the image to rapidly move to the position of the image center. Therefore, the number of times and time required by calibration are reduced, and the calibration efficiency is improved.

In some embodiments, the preset value carried by the second instruction in S403 is gradually increased from 0, and the image capturing module in S405 captures corresponding images when the gain of the motor is adjusted to different preset values. Correspondingly, in S406, the personal computer may acquire the images acquired by the camera module when different motor gains are obtained.

In some embodiments, the step S406 includes: acquiring a first image acquired by the camera module when the gain of the motor is set to be a first gain; the first gain is greater than or equal to 0. Then, the personal computer performs S407 and S408, and if it is determined that the center of shake of the first image is outside the first image, increases or decreases based on the first gain with a first preset step size to obtain the gain of the motor.

In other embodiments, during the process of increasing or decreasing the gain of the motor from the initial value, acquiring a second image acquired by the camera module when the gain of the motor is set to a second gain; if the dithering center of the second image is within the second image, increasing or decreasing a second preset step length on the basis of the second gain to obtain a third gain, and acquiring a third image acquired by the camera module; determining a target step length based on the moving distance between the dithering center of the second image and the dithering center of the third image and a second preset step length; and increasing or reducing the target step length on the basis of the third gain to obtain a fourth gain, and acquiring a fourth image acquired by the camera module when the gain of the motor is set to the fourth gain.

The second preset step size and the first preset step size may be set to be the same or different. In the embodiment of the present application, after the personal computer determines that the center of shake starts to appear in the image, the motor gain may be adjusted only once; i.e. a third gain is obtained for the second gain adjustment. And then analyzing a third image acquired by the camera module when the motor is set to be at a third gain, and determining the jitter center position of the third image. And determining the distance that the jitter center position of the third image moves compared with the jitter center position of the second image. The correlation between the change in gain and the change in jitter center can be determined by combining the difference between the third gain and the second gain, i.e., the second preset step size. And then, determining an adjustment value of the gain required to be adjusted by moving the dithering center to the image center on the basis of the third image, namely the target step size by combining the distance between the dithering center position of the third image and the image center and the association relation between the gain change and the dithering center change.

Finally, the personal computer can send a target step length to the camera module, instruct the camera module to control the motor to adjust according to the target step length on the basis of the third gain, and obtain a fourth gain. At this time, the camera module collects a fourth image from the first preset calibration board, and according to the above relationship, the shake center of the fourth image almost overlaps with the image center, that is, the distance between the shake center and the image center satisfies the preset condition. Then, the camera module sends the fourth image to the personal computer, and the personal computer sequentially executes S408 and S409 on the fourth image, so that the distance between the shake center and the image center of the fourth image will be obtained to meet the preset condition. Then, in S410, the personal computer may directly determine the fourth image as the target image. Therefore, the frequency required by calibration is reduced, and the efficiency of OIS calibration is improved.

It will be appreciated that the dither centers of the above-described second and third images are respectively within the respective images, but not at the image center.

In the technical scheme provided by the embodiment of the application, in the calibration process of optical anti-shake, the gain of the control motor is sequentially increased or decreased, so that the positions of shake centers in different images are changed towards one direction, and images with shake centers close to the image centers can be conveniently and quickly found. Thus, the OIS calibration speed can be improved.

After S410, that is, after the target image is found, the target image is an image that can make the OIS effect of the camera module best. It can be determined that the amount of blurring of the position where the center of shake of the target image is located is almost zero. If the center of the shake is at the center position of a certain feature point, the blurring amount of the feature point is almost zero. If the center of the shake does not completely coincide with the center position of any one of the feature points, the amount of blurring of the feature points in the nearer range of the position of the center of the shake is also smaller. After the feature point with the smallest amount of blur is found in the target image, the motor performance can be evaluated using the amount of blur of the feature point with the smallest amount of blur. In some embodiments, evaluating the performance of the motor may be accomplished by calculating the compression ratio.

In some embodiments, after the step S410, as shown in fig. 10, the method further includes steps S1000 to S1006, where:

s1000, under the second shooting state, the camera module acquires a fifth image of the first preset calibration plate.

The second shooting state is a shooting state in which the camera module is in a vibration state and the OIS function is closed.

In some embodiments, the camera module may turn off the OIS function of the camera module in response to an instruction from the personal computer. In this embodiment, before the above S1000, further includes: the personal computer sends a fourth instruction to the camera module, wherein the fourth instruction is used for controlling the camera module to close the OIS function. In other embodiments, the OIS function of the camera module may also be manually turned off by the relevant personnel.

In some embodiments, when the camera module in S1000 captures an image, the test device still controls the vibration table to vibrate according to the preset vibration parameter, so as to drive the camera module to vibrate.

S1001, the camera module sends a fifth image to the personal computer.

S1002. the personal computer sends a fifth instruction to the test preparation.

S1003, responding to a fifth instruction by the testing device, and controlling the vibration table to stop vibrating.

The fifth instruction is used for instructing the test equipment to control the vibration table to stop vibrating, so that the camera module can keep a stable state to collect a sixth image. It will be appreciated that in other embodiments, the vibration of the vibrating table may also be manually turned off by an associated person.

S1004, under the third shooting state, the camera module acquires a sixth image of the first preset calibration plate.

Under the third shooting state, the shooting module is kept stable.

S1005, the camera module sends a sixth image to the personal computer.

S1006, the personal computer determines the compression ratio based on the blur amounts of the feature points in the target image, the fifth image, and the sixth image.

In one embodiment, the compression ratio refers to the compression ratio of the image, which may be used to indicate the performance of the motor. As is apparent from the description of the above embodiments, the shake in the target image has been minimized, and the blur amount of the feature points in the target image is minimized. Then the blurring due to the external vibrations has been counteracted by the compensation of the motor for the feature points in the target image, which is almost negligible. If there is still a blur in the target image, the blur may be due to the motor's own performance, which may not be fully compensated for. Therefore, in the case where the external vibration is the same, the compression ratio can be calculated for evaluating the performance of the motor in combination with the target image (OIS on) and the image acquired with OIS off.

In some embodiments, the step S1004 may specifically include: and acquiring corresponding fuzzy amounts of the target feature points in the first preset calibration plate in the target image, the fifth image and the sixth image respectively. The compression ratio is calculated based on the corresponding blur amounts of the target feature points in the target image, the fifth image, and the sixth image. The target feature point may be any one or more feature points in the target image. In some embodiments, the target feature point may be a feature point in the target image where jitter is minimal.

In some embodiments, the target feature point may be a feature point corresponding to a position of the center of shake in the target image, as shown by 803 in fig. 8. In other embodiments, if the shake center of the target image does not coincide with a feature point in any one of the first preset calibration plates, a feature point closest to the shake center in the target image may be used as the target feature point.

After the target feature points are selected, the target feature points are found in the target image, the fifth image and the sixth image respectively, and the blur amounts in the target image, the fifth image and the sixth image are acquired respectively. The compression ratio is then determined based on the three blur amounts.

The specific implementation manner of obtaining the blur amount of the feature points in the image may refer to the description in the related art, which is not repeated in the embodiment of the present application.

In some embodiments, the compression ratio is calculated based on the corresponding blur amounts of the target feature point in the target image, the fifth image and the sixth image, and may be specifically implemented by the following formula:

CR=-20Log10（(OIS on-Still)/(OIS off- Still)）；

where CR (Compression Ratio) denotes the compression ratio, OIS on denotes the amount of blur corresponding to the target feature point in the target image, OIS off denotes the amount of blur corresponding to the target feature point in the fifth image, and Still denotes the amount of blur corresponding to the target feature point in the sixth image.

In embodiments where the target feature point includes a plurality of target feature points, the corresponding compression ratio may be calculated for each target feature point using the above formula, respectively. Then, an average value is calculated for the compression ratios corresponding to the different target feature points as the compression ratio for evaluating the motor performance.

In the embodiment of the application, the fuzzy amount of the target characteristic points in the image acquired by the camera module in the vibration state and the OIS function is started, and the fuzzy amount of the target characteristic points in the image acquired by the camera module in the vibration state and the OIS function is closed are respectively subtracted, so that the influence of other external factors on the compression ratio calculation can be reduced.

In the technical scheme provided by the embodiment of the application, after the gain of the motor is calibrated by using the scheme of S401-S410, the compression ratio is calculated by combining the fuzzy quantity of the characteristic points in the image when the motor of the camera module is set to be a calibrated gain value, so that the performance of the motor is evaluated. Because the motor is calibrated through the schemes of S401-S410, a calibration gain value with higher precision can be obtained, and therefore, a more accurate evaluation result can be obtained by evaluating the performance of the motor under the state of the calibration gain value.

In some embodiments, the camera module in S405 may use different parameters to collect images of the first preset calibration plate. In some embodiments, the parameters of the camera module include frame rate and exposure time. When the camera module collects images through low frame rate and long exposure time, the collected characteristic points in the images and the images formed by the fuzzy parts of the characteristic points are denser. Therefore, in this embodiment, in calculating the above compression ratio, the amount of blurring of the target feature point in the target image can be expressed by the area of the center motion trajectory of the target feature point for the target feature point and the blurring portion of the target feature point.

When the camera module acquires an image through a high frame rate and a low exposure time, the acquired characteristic points in the image and the image formed by the blurred parts of the characteristic points are relatively less dense. In this embodiment, therefore, in calculating the above compression ratio, the amount of blurring of the target feature point in the target image can be expressed by the length of the center motion trajectory of the target feature point for the target feature point and the blurring portion of the target feature point.

The embodiment of the application also provides another optical anti-shake calibration method, which can realize OIS calibration of the periscope type camera module by using a calibration plate with single characteristic point. As can be seen from the above description, if the OIS calibration of the periscope type camera module is implemented by using the calibration board with single feature points, the single feature points are not necessarily located at the center of the picture of the lens when the image is lighted, so that the position targeted by the OIS calibration is not the center of the picture, and the calibration accuracy is not high. To avoid this, in the embodiment of the present application, when the image capturing module lights up the screen, the position of the single feature point in the screen is determined first, and then the position is compensated for the center. Specifically, a single feature point can be moved to the center of the lens screen by adjusting the stroke of the motor. And then, the OIS calibration is carried out on the camera module, so that the position aimed by the OIS calibration process is ensured to be the position of the center of the lens picture of the camera module.

In some embodiments, as shown in fig. 11, the calibration method for optical anti-shake provided in the embodiment of the present application may include S1101-S1113, where:

s1101, the camera module collects calibration images for the second preset calibration plate.

The second preset calibration plate comprises at least one characteristic point.

In some embodiments, the second preset calibration plate includes a single feature point, and the single feature point in the second preset calibration plate may be set as a center position of the calibration plate. The shape of the single feature point in the second preset calibration plate may be any shape, such as a circle, square, triangle, or cross shape, etc. The size of the single characteristic point in the second preset calibration plate can be set according to actual conditions. It should be appreciated that when the OIS calibration is performed on the camera module using the second preset calibration plate, the second preset calibration plate is disposed within the view-finding range of the camera module.

In some embodiments, the second preset calibration plate may also include a plurality of feature points.

The arrangement of the camera module can be referred to as the arrangement in fig. 3.

In some embodiments, the camera module may capture images of the second preset calibration plate in response to instructions from the personal computer. In this embodiment, before the above S1101, further comprising: the personal computer sends a sixth instruction to the camera module, wherein the sixth instruction is used for instructing the camera module to collect images. In other embodiments, the process of capturing images by the camera module may also be manually triggered by the relevant personnel.

S1102, the camera module sends the calibration image to the personal computer.

S1103, the personal computer acquires a first position of the preset feature point in the calibration image and a distance between the first position and an image center of the calibration image.

If the second preset calibration plate comprises a single feature point, the preset feature point is the single feature point. If the second preset calibration plate comprises more than two characteristic points, the preset characteristic points can be any one of the characteristic points; the preset feature point may be specified in advance. In some embodiments, when the second preset calibration plate includes more than two feature points, the preset feature points may be feature points disposed at a central position in the second preset calibration plate. Similar to the first preset calibration plate in the above embodiment, the size, shape, color and interval between the feature points of the second preset calibration plate may be set according to the actual situation, which is not limited in the embodiment of the present application.

The preset feature point may or may not be located in the center of the calibration image in the calibration image, for example, may be the position shown as 12, 13, 14 or 15 in fig. 1. The picture center of the camera module is the image center of the calibration image acquired by the camera module. It will be appreciated that if the first position is at the image center position of the calibration image, then the distance between the first position and the image center of the calibration image is 0.

S1104, sending a seventh instruction to the camera module based on the distance between the first position and the image center of the calibration image.

The seventh instruction is used for instructing the camera module to adjust the stroke of the motor so that the preset characteristic point is positioned at the center of the picture of the camera module. The stroke of the motor indicates the range in which the motor can move. In some embodiments, the seventh instruction carries a target adjustment value for the motor stroke; the seventh instruction is used for instructing the camera module to adjust the motor stroke based on the target adjustment value.

In some embodiments, the step S1104 is performed when the preset feature point in the calibration image is not located in the center of the image. If the preset characteristic point is positioned at the center of the image in the calibration image, the stroke of the motor does not need to be adjusted.

In some embodiments, after the distance between the first position in the calibration image and the center of the image of the camera module is obtained, it may be determined how to adjust the stroke of the motor to enable the preset feature point to move to the center of the image based on the distance. The adjustment method for determining the motor stroke based on the distance may refer to the description of the related art, and will not be described in detail in the embodiments of the present application.

In some embodiments, S1104 above may take the short side position of Hall calibration (Hall cal) as the upstroke and calculate the downstroke from the code position when determining the target adjustment value of the motor stroke. Where code represents the value that moves to a certain distance image becomes clear.

S1105, the camera module responds to the seventh instruction to adjust the stroke of the motor.

It should be understood that, after the camera module adjusts the stroke of the motor in response to the seventh command, the preset feature point in the second preset calibration plate will appear in the center of the image of the camera module. Therefore, after S1105, the OIS calibration is performed on the camera module, so that the problem of low OIS calibration accuracy caused by the fact that the preset feature point is located at the non-picture center can be avoided. That is, the second preset calibration plate may be used to perform OIS calibration on the camera module, and a more accurate calibration result may also be obtained.

S1106, the personal computer sends a first instruction to the testing equipment.

S1107, the camera shooting module responds to the first instruction, and the vibration table is controlled to vibrate according to preset vibration parameters.

S1108, the personal computer sends a second instruction to the camera module.

S1109, the camera module responds to the second instruction, and the gain of the motor of the camera module is controlled to be adjusted to be a preset value.

S1110, the camera module collects corresponding images for the second preset calibration plate.

S1111, the camera module sends images to the personal computer.

The specific implementation process of S1106 to S1111 described above may refer to the descriptions of S401 to S406 in the above embodiments.

S1112, the personal computer acquires the shaking condition of preset feature points in the image.

As is apparent from the description of the above embodiments, the larger the shake of the preset feature point, the larger the blur amount of the preset feature point in the image. Thus, in some embodiments, the personal computer may calculate the amount of blur of the preset feature points in the image. The specific implementation manner of calculating the blur amount of the feature points in the image may refer to the description in the related art, which is not repeated in the embodiment of the present application.

S1113, the personal computer determines a calibration gain value of the motor according to the shaking conditions of preset feature points in images corresponding to different motor gain values.

When motors of the camera module are set to different values, the compensation effect on blurring caused by external vibration is inconsistent, so that shake of a single feature point is inconsistent. In the OIS calibration process of the camera module, a motor gain value that can make the compensation effect best needs to be found, that is, a corresponding motor gain value that can minimize the jitter of the preset feature point needs to be found. That is, the smaller the blurring amount of the preset feature point, the better the compensation effect.

Thus, in some embodiments, S1113 may specifically include: the personal computer searches images with minimum blur (namely minimum shake) of preset feature points in the images, obtains a motor gain value corresponding to the image with the minimum blur, and determines the motor gain value as a calibration gain value of the camera module.

Fig. 12 is a schematic diagram of an image acquired by the camera module on the second preset calibration plate in the process of S1101-S1113 in the embodiment of the present application. In the example of fig. 12, the second preset calibration plate includes a single feature point, and the single feature point is a circular feature point. A in fig. 12 is a schematic view of an image acquired at S1101, and the single feature point 1201 is not in the center of the image. In fig. 12 b, after the camera module adjusts the stroke of the motor, the single feature point 1202 is located at the center of the image, i.e. the center of the image of the camera module, for the image schematic acquired by the second preset calibration plate. In fig. 12 c, in S1110, the image capturing module captures one of the images of the preset calibration plate in the third capturing state, where a single feature point is blurred. In fig. 12, d is a schematic diagram of an image acquired by the second preset calibration plate when the motor of the camera module is adjusted to the calibration gain value after the calibration gain value of the motor is found in S1113, and the blur of a single feature point is small.

The imaging module for OIS calibration using the method of S1101 to S1113 also needs to store the target adjustment value of the stroke of the motor as the calibration result. When the camera module is put into use, the motor stroke is adjusted according to the target adjustment value, and then the OIS processing is carried out on the calibrated gain value of the motor obtained by the method, so that a good anti-shake effect can be obtained. In some embodiments, the method of S1101-S1113 is applicable to an image capturing module with better linearity and crosstalk after motor compensation.

In the technical scheme provided by the embodiment of the application, the imaging module which carries out OIS processing in the X direction and the Y direction of the prism is subjected to OIS calibration by using the calibration plate comprising the single characteristic point, and the single characteristic point is ensured to appear in the center of a picture of the imaging module by changing the stroke of the motor. Therefore, the problem of low OIS calibration accuracy caused by the fact that a single characteristic point is not located in the center of a picture can be avoided.

Further embodiments of the present application provide a computer device, which may be a personal computer as described above. The computer device may include: a memory and one or more processors. The memory is coupled to the processor. The memory is also used to store computer program code, which includes computer instructions. When the processor executes the computer instructions, the computer device may perform the various functions or steps performed by the personal computer in the method embodiments described above. When the computer device is an electronic device, the structure thereof can be referred to as the structure of the personal computer 20 shown in fig. 2.

The present application also provides a chip system, as shown in fig. 13, where the chip system 130 includes at least one processor 1301 and at least one interface circuit 1302. The processor 1301 and the interface circuit 1302 may be interconnected by wires. For example, interface circuit 1302 may be used to receive signals from other devices (e.g., a memory of a computer apparatus). For another example, interface circuit 1302 may be used to send signals to other devices (e.g., processor 1301). Illustratively, the interface circuit 1302 may read instructions stored in the memory and send the instructions to the processor 1301. The instructions, when executed by processor 1301, may cause a computer device to perform the various steps of the embodiments described above. Of course, the system-on-chip may also include other discrete devices, which are not particularly limited in accordance with embodiments of the present application.

Embodiments of the present application also provide a computer-readable storage medium including computer instructions that, when executed on a personal computer as described above, cause the electronic device to perform the functions or steps performed by the personal computer in the method embodiments described above.

Embodiments of the present application also provide a computer program product which, when run on a computer, causes the computer to perform the functions or steps performed by the personal computer in the method embodiments described above. Wherein the computer may be an electronic device such as a personal computer.

It will be apparent to those skilled in the art from this description that, for convenience and brevity of description, only the above-described division of the functional modules is illustrated, and in practical application, the above-described functional allocation may be performed by different functional modules according to needs, i.e. the internal structure of the apparatus is divided into different functional modules to perform all or part of the functions described above.

In the several embodiments provided by the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of modules or units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another apparatus, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and the parts shown as units may be one physical unit or a plurality of physical units, may be located in one place, or may be distributed in a plurality of different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a readable storage medium. Based on such understanding, the technical solution of the embodiments of the present application may be essentially or a part contributing to the prior art or all or part of the technical solution may be embodied in the form of a software product stored in a storage medium, including several instructions for causing a device (may be a single-chip microcomputer, a chip or the like) or a processor (processor) to perform all or part of the steps of the methods of the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read Only Memory (ROM), a random access memory (random access memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

The foregoing is merely illustrative of specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions within the technical scope of the present application should be covered by the scope of the present application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims

1. An optical anti-shake calibration method, comprising:

acquiring N images acquired by the camera module under a first shooting state on a first preset calibration plate; the first preset calibration plate comprises at least one characteristic point, and N is a positive integer greater than 2; the N images are acquired when motors of the camera module are set to different gains respectively; the first shooting state includes: the camera module vibrates and an optical anti-shake function of the camera module is started; when the optical anti-shake function of the camera module is started and the camera module performs image acquisition, the motor drives the lens of the camera module to move so as to compensate the blurring caused by the vibration of the camera module;

acquiring the jitter conditions of the characteristic points in each of the N images, and determining the jitter center of each image according to the jitter conditions of the characteristic points in each of the N images; the jitter center is used for indicating the position with minimum jitter in the image;

Searching target images of which the distances between the shaking centers and the image centers meet preset conditions from the N images; the preset condition is used for indicating that the distance between the dithering center of the image and the center of the image is minimum, and the distance is smaller than a first preset threshold value;

and acquiring a target gain corresponding to the motor when the target image is acquired, and determining the target gain as a calibrated gain value of the motor.

2. The method according to claim 1, wherein the acquiring the jitter condition of the feature points in each of the N images and determining the jitter center of each of the N images according to the jitter condition of the feature points in each of the N images includes:

filtering the N images to obtain N filtered images; the filtered image includes at least one feature object corresponding to the at least one feature point; each feature object comprises a corresponding feature point and a fuzzy part corresponding to the corresponding feature point;

and determining the position of the jitter center in the image corresponding to each filtered image based on the size of at least one feature object in each filtered image of the N filtered images.

3. The method according to claim 2, wherein determining the position of the dithering center in the image corresponding to each of the N filtered images based on the size of at least one feature object in each of the N filtered images comprises:

searching the minimum feature object in at least one feature object in each of the N filtered images;

and determining the position of the jitter center in the image corresponding to each filtered image based on the minimum feature object in each filtered image.

4. A method according to claim 3, wherein determining the location of the dither center in the image corresponding to each filtered image based on the minimum feature object in each filtered image comprises:

in the target filtered image, if the minimum feature object is at the edge of the target filtered image and the size of the minimum feature object exceeds a second preset threshold, determining that the jitter center is beyond the image corresponding to the target filtered image; the target filtered image is any one of the N filtered images;

In the target filtered image, if the minimum feature object is not located at the edge of the target filtered image, or the size of the minimum feature object does not exceed the second preset threshold, determining the position of the jitter center based on the position of the minimum feature object in the target filtered image.

5. The method of claim 4, wherein the determining the location of the dither center based on the location of the minimum feature object in the target filtered image comprises:

if the minimum feature object comprises a feature object, determining the position of the center of the minimum feature object as the position of the shake center;

if the minimum feature object comprises more than two feature objects, fitting the position of the jitter center based on the position of the minimum feature object.

6. The method of claim 1, wherein the acquiring N images acquired by the camera module in the first shooting state on the first preset calibration plate includes:

the gain of the motor is increased or decreased from an initial value, and when the motor is set to be different gains, the image acquired by the camera module on the first preset calibration plate in the first shooting state is correspondingly acquired.

7. The method of claim 6, wherein the obtaining the jitter condition of the feature points in each of the N images and determining the jitter center of each of the N images according to the jitter condition of the feature points in each of the N images comprises:

after a current image acquired by the camera module when the motor is set to be a current gain is acquired, acquiring the jitter condition of the characteristic points in the current image, and determining the jitter center of the current image according to the jitter condition of the characteristic points in the current image;

the method further comprises the steps of:

and stopping acquiring the image acquired by the camera module on a first preset calibration plate in a first shooting state when the distance between the jitter center of the current image and the image center of the current image is determined to meet the preset condition.

8. The method of claim 6, wherein the gain of the motor is incremented or decremented from an initial value, comprising:

in the process of increasing or decreasing the gain of the motor from the initial value, if the jitter center of the first image corresponding to the first gain is outside the first image, increasing or decreasing the gain based on the first gain with a first preset step length.

9. The method of claim 6, wherein the gain of the motor is increased or decreased from an initial value, and when the motor is set to a different gain, the corresponding acquiring the image acquired by the camera module in the first shooting state for the first preset calibration plate includes:

acquiring a second image acquired by the camera module when the gain of the motor is set to be a second gain in the process of increasing or decreasing the gain of the motor from an initial value;

if the dithering center of the second image is within the second image, increasing or decreasing a second preset step length on the basis of the second gain to obtain a third gain, and acquiring a third image acquired by the camera module;

determining a target step length based on the moving distance of the dithering center of the second image and the dithering center of the third image and the second preset step length;

and increasing or decreasing the target step length on the basis of the third gain to obtain a fourth gain, and acquiring a fourth image acquired by the camera module when the gain of the motor is set to the fourth gain.

10. The method according to any one of claims 1-9, wherein the at least one feature point comprises more than two feature points.

11. The method of claim 10, wherein the first predetermined calibration plate comprises a plurality of circular feature points that are periodically arranged and of the same size.

12. The method according to any one of claims 1 to 9, wherein after searching for a target image in which a distance between a shake center and an image center satisfies a preset condition among the N images, the method further comprises:

acquiring a fifth image acquired by the camera module in a second shooting state on the first preset calibration plate; in the second shooting state, the camera module vibrates and the optical anti-shake function of the camera module is closed;

acquiring a sixth image acquired by the camera module in a third shooting state of the first preset calibration plate; in the third shooting state, the camera module is kept stable;

a compression ratio indicating performance of the motor is determined based on the blur amounts of the feature points in the target image, the fifth image, and the sixth image.

13. The method of claim 12, wherein the determining the compression ratio based on the blur amounts of the feature points in the target image, the fifth image, and the sixth image comprises:

Obtaining corresponding fuzzy amounts of target feature points in the first preset calibration plate in the target image, the fifth image and the sixth image respectively; the target feature points comprise feature points with minimum jitter in the target image;

the compression ratio is calculated based on the corresponding blur amounts of the target feature points in the target image, the fifth image, and the sixth image.

14. The method of claim 13, wherein the calculating the compression ratio based on the corresponding blur amounts of the target feature points in the target image, the fifth image, and the sixth image comprises:

the compression ratio is calculated based on the following formula:

CR=-20Log10（(OIS on-Still)/(OIS off- Still)）；

wherein CR represents the compression ratio, OIS on represents the corresponding blur amount of the target feature point in the target image, OIS off represents the corresponding blur amount of the target feature point in the fifth image, and Still represents the corresponding blur amount of the target feature point in the sixth image.

15. An optical anti-shake calibration method, comprising:

acquiring a calibration image acquired by the camera module on a second preset calibration plate; the second preset calibration plate comprises at least one characteristic point;

Acquiring a first position of a preset feature point in the second preset calibration plate in the calibration image and a distance between the first position and an image center of the calibration image;

adjusting the stroke of a motor of the camera module based on the distance between the first position and the image center of the calibration image so that the preset feature point is positioned in the image center;

acquiring M images acquired by the camera module in a third shooting state on the second preset calibration plate; the third shooting state comprises that the camera module vibrates and the optical anti-shake function of the camera module is started; when the optical anti-shake function of the camera module is started and the camera module performs image acquisition, the motor drives the lens of the camera module to move so as to compensate the blurring caused by the vibration of the camera module; m is a positive integer greater than or equal to 2;

obtaining jitter conditions of preset feature points in each image of the M images;

and determining a calibration gain value of the motor based on the jitter condition of preset feature points in each image of the M images.

16. An electronic device, the electronic device comprising: a processor and a memory; the memory has stored therein computer program code comprising computer instructions which, when executed by the processor, cause the electronic device to perform the method of any of claims 1-15.

17. A computer readable storage medium comprising computer instructions which, when run on an electronic device, cause the electronic device to perform the method of any of claims 1-15.