WO2017107842A1

WO2017107842A1 - Zoom tracking curve calibration method and device

Info

Publication number: WO2017107842A1
Application number: PCT/CN2016/110133
Authority: WO
Inventors: 林铁楠
Original assignee: 北京奇虎科技有限公司
Priority date: 2015-12-23
Filing date: 2016-12-15
Publication date: 2017-06-29
Also published as: CN105611159A

Abstract

The invention relates to the technical field of monitoring, especially relates to a calibration method and device of a zoom tracking curve. The method comprises: selecting N collection points on a reference zoom tracking curve, wherein the N collection points correspond to different zooming ratio values; obtaining the corresponding theoretical focusing location value of a certain collection point in the N collection points on the reference zoom tracking curve; on the basis of a preset automatic focusing algorithm, obtaining an actual focusing location value at a zooming ratio value corresponding to the collection point when the focusing estimation value becomes the maximum; repeatedly executing the above steps, and respectively obtaining the actual focusing location values and the theoretical focusing location values corresponding to the N collection points, thus finishing the calibration of the reference zoom tracking curve. The own actual zoom tracking curve of each lens can be obtained and its synchronous operation with the calibrated actual reference zooming tracking curve in the follow-up zooming and automatic focusing processes can be ensured such that the image is focused clearly in the whole zooming process.

Description

Method and device for correcting zoom tracking curve

[Technical Field]

The present invention relates to the field of camera monitoring technology, and in particular, to a method and apparatus for correcting a zoom tracking curve.

【Background technique】

The existing integrated camera has the functions of zooming and auto focusing, and has a compact structure, convenient use and wide monitoring range, and has been widely used in the field of video surveillance. In the integrated camera lens, the zoom lens and the focus lens are separately moved and driven by the zoom motor and the focus motor respectively. During zooming, zoom tracking is required to make the focus lens change synchronously according to the position of the zoom lens, thereby making the image Ability to focus clearly.

Usually, the lens manufacturer will provide a fixed ideal zoom tracking curve corresponding to the lens, which is convenient for the camera to achieve zoom tracking and auto focus according to the zoom tracking curve. However, due to the individual differences of the lens, when using a certain lens, it is necessary to adjust and confirm the optical reference position of each lens for zooming and focusing to obtain the most suitable zoom tracking curve, if the fixed ideal zoom tracking curve is used. When doing zoom tracking, the image may have varying degrees of blur. Therefore, before or during the lens zoom tracking process, if the actual zoom tracking curve of each lens itself can be synchronized, the image of the entire zoom process can be focused clearly. So how to get the actual zoom tracking curve of each lens is a technical problem that needs to be solved.

[Summary of the Invention]

An object of the present invention is to solve at least the above problems, and to provide a method for correcting a zoom tracking curve and an apparatus using the same.

To achieve the object, the embodiment of the present invention adopts the following technical solutions:

Embodiments of the present invention provide a method for correcting a zoom tracking curve, which includes:

N acquisition points are selected on the reference zoom tracking curve, and the N collection points correspond to different zoom magnification values;

Obtaining a theoretical focus position value corresponding to a sampling point of the N collection points on the reference zoom tracking curve;

Obtaining an actual focus position value when the focus estimation value reaches a maximum at a zoom magnification value corresponding to the collection point based on a preset auto focus algorithm;

Repeating the above steps, respectively acquiring actual focus position values and theoretical focus position values corresponding to the N collection points, and corresponding correction distances of the reference zoom tracking curves on the N collection points, to complete the reference zoom tracking curve. Correction.

According to another aspect of the embodiments of the present invention, an embodiment of the present invention further provides a calibration apparatus for a zoom tracking curve, including:

a sampling module, configured to select N collection points on the reference zoom tracking curve, the N collection points corresponding to different zoom magnification values;

a theoretical value obtaining module, configured to acquire a theoretical focus position value corresponding to a sampling point of the N collection points on the reference zoom tracking curve;

An actual value obtaining module, configured to acquire, according to a preset autofocus algorithm, an actual focus position value when a focus estimation value reaches a maximum under a zoom magnification value corresponding to the collection point;

a correction module, configured to repeatedly invoke the foregoing modules to perform corresponding operations, respectively acquiring the N collection point pairs The actual focus position value and the theoretical focus position value, and the corresponding correction distance of the reference zoom tracking curve at the N acquisition points, to complete the correction of the reference zoom tracking curve.

According to still another aspect of an embodiment of the present invention, a computer program is provided, comprising computer readable code, when the computer readable code is run on a terminal device, causing the terminal device to perform any of the zoom tracking described above The correction method of the curve.

According to still another aspect of an embodiment of the present invention, there is provided a computer readable medium storing a computer program for performing a correction method of any one of the above-described zoom tracking curves.

Compared with the prior art, the embodiment of the invention has the following advantages:

Embodiments of the present invention provide a method and apparatus for correcting a zoom tracking curve, which acquires theoretical focus position values corresponding to the collection points by selecting N collection points of different zoom magnification values on a theoretical reference zoom tracking curve; According to the preset auto-focus algorithm, the actual focus position value when the focus estimation value reaches the maximum under the zoom magnification value corresponding to the collected points is obtained, based on the actual focus position value and the theoretical focus position value, and the correction distance between the two. , to complete the correction of the reference zoom tracking curve. That is, the embodiment of the present invention can obtain the actual zoom tracking curve of each lens itself, thereby ensuring that the actual reference zoom tracking curve that has been corrected is synchronously operated during zooming and auto focusing, so that the entire zoom process image can be focused clearly. .

The additional aspects and advantages of the embodiments of the present invention will be set forth in part in the description in the description.

[Description of the Drawings]

The above and/or additional aspects and advantages of the embodiments of the present invention will become apparent and readily understood from

1 is a flowchart of a process of an embodiment of a zoom tracking curve correction method according to an embodiment of the present invention;

2 is a schematic diagram of a theoretical zoom tracking curve preset in an embodiment of the present invention;

3 is a schematic diagram of selecting a collection point on a zoom tracking curve in an embodiment of the present invention;

4 is a flowchart of a process of an embodiment of a zoom tracking curve correction method according to an embodiment of the present invention;

FIG. 5 is a structural block diagram of an embodiment of a zoom tracking curve correcting apparatus according to an embodiment of the present invention; FIG.

6 is a structural block diagram of a reference curve selection module in an embodiment of a zoom tracking curve correction device according to an embodiment of the present invention;

FIG. 7 is a block diagram of a terminal device for performing a method according to an embodiment of the present invention;

8 is a memory unit of an embodiment of the present invention for holding or carrying program code that implements a method in accordance with an embodiment of the present invention.

【detailed description】

The embodiments of the present invention are further described in the following with reference to the drawings and the exemplary embodiments, which are illustrated in the accompanying drawings, in which the same or the Components. The embodiments described below with reference to the accompanying drawings are intended to be illustrative of the embodiments of the invention. Further, if a detailed description of a known technique is unnecessary for the features of the embodiments of the present invention, it will be omitted.

Those skilled in the art will understand that the singular forms "a", "an", "The" and "the" may also include the plural. It is to be understood that the phrase "comprise" or "an" Features, integers, steps, operations, components, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element. Further, "connected" or "coupled" as used herein may include either a wireless connection or a wireless coupling. The phrase "and/or" used herein includes all or any one and all combinations of one or more of the associated listed.

Those skilled in the art will appreciate that all terms (including technical and scientific terms) used herein have the same meaning as the ordinary meaning of the ordinary It should also be understood that terms such as those defined in a general dictionary should be understood to have meaning consistent with the meaning in the context of the prior art, and will not be idealized or excessive unless specifically defined as here. The formal meaning is explained.

It should be noted that the method in the embodiment of the present invention is a process of zooming and autofocusing when an image is taken by a camera or a camera. Of course, the method according to the embodiment of the present invention can also be applied to a mobile phone with a zoom, auto focus function, a PAD, a portable multimedia player (PMP), a TV, and the like.

1 is a flowchart of a process of a zoom tracking curve correction method according to an embodiment of the present invention, which includes the following steps:

S11, N collection points are selected on the reference zoom tracking curve, and the N collection points correspond to different zoom magnification values.

It should be noted that it is necessary to provide a pilot description of the zoom tracking curve. It is not difficult to understand that at least two zoom tracking curves having different focus distances are input in advance in the lens, please refer to FIG. 2. In the coordinate system described in FIG. 2, the horizontal axis represents the zoom magnification value, and the vertical axis represents the focus position value. For convenience of explanation, the zoom distances of 3 m, 6 m, 10 m, and infinity are selected in the present scheme. The tracking curve is taken as an example to illustrate. It can be seen that when the zoom motor position is at a small zoom magnification value, the zoom tracking curves of the four different focus distances are substantially coincident; when the zoom magnification becomes larger, the zoom tracking curves of different focus distances are gradually separated, and the distance difference is more and more different. Big. This shows that when the zoom motor position is at a small zoom magnification value, the focus position of the motor does not change much as the distance of the object from the lens changes, but at high zoom magnification, once the object distance changes greatly, the position of the focus motor also A large deviation follows. Therefore, during zooming of the lens, first select a reference zoom tracking curve that best matches the current focus distance.

Specifically, in an embodiment of the present invention, before step S11, the method further includes the step of: selecting a reference zoom tracking from the pre-stored at least two zoom tracking curves having different focus distances based on the preset first rule. curve. It is not difficult to understand that the zoom tracking curves having different at least two different focusing distances are input to the imaging lens and stored in advance, for example, may be stored in advance in a storage medium, wherein the storage medium may be a synchronous dynamic random access memory (SDRAM). Multi-chip package (MCP) memory or dynamic random access memory (DRAM).

Specifically, in an embodiment of the embodiment of the present invention, the initial zoom magnification value and the initial focus focus position value obtained when starting zooming are matched with the plurality of zoom tracking curves, and the closest one of the zooms is selected. The trace curve is used as a reference zoom tracking curve. Referring to FIG. 4, the selected reference zoom tracking curve specifically includes the following steps:

S101, when zooming is started, acquiring a current zoom motor position and a focus motor position, thereby obtaining an initial zoom magnification value and an initial focus position value;

S102. Acquire, on each zoom tracking curve, a focus position value corresponding to the initial zoom magnification value.

S103. Select a zoom tracking curve whose focus position value is closest to the initial focus position value as the reference zoom tracking curve.

Specifically, during the zooming process of the camera lens, obtaining the current zoom motor position and the position of the focus motor, the corresponding initial zoom magnification value and the initial value focus position value are obtained; and then the initial zoom magnification value is different from the pre-stored plurality of pieces according to the initial zoom magnification value. Obtaining a corresponding focus position value in the zoom tracking curve of the focus distance; then comparing the initial focus position value with the obtained plurality of focus position values, and selecting a zoom tracking curve corresponding to the closest focus position value as the reference zoom tracking curve. Of course, this embodiment is applicable when the magnification value of the lens is greater than a certain value, that is, when the zoom tracking curves of different focus distances are distinct, the embodiment is suitable for zooming from a small zoom magnification value to a large zoom magnification value. In the direction, and the current zoom magnification value is less than a certain value, that is, when the zoom tracking curves of different focus distances are more coincident under the current zoom magnification value, it is necessary to select several initial values to compare.

Further, after the reference zoom tracking curve is selected, it is also required to select N collection points on the reference zoom tracking curve, and the N collection points correspond to different zoom magnification values.

It is not difficult to understand that under a small zoom magnification value, the zoom tracking curve of different focus distances has a high degree of coincidence, and fewer acquisition points should be selected at a small zoom magnification value; conversely, at a large zoom magnification value, different The zoom tracking curves of the focus distance are gradually separated, so that at a large zoom magnification value, more collection points are selected. That is, the number of collection points selected at different positions on the reference zoom tracking curve is proportional to the zoom odds value corresponding to the current position, and the specific sampling schematic is shown in FIG. 3. For example, in an embodiment of the present invention, the interval Tx of the collection point may be set to an inversely proportional to the zoom magnification value, so that the processor in the lens obtains the corresponding N according to the interval value calculated by the algorithm. Collection points. The embodiment is of course only exemplary, which is not limited by the embodiment of the present invention.

Further, referring to FIG. 1, in an embodiment of the method of the present invention, the method further includes the following steps:

S12. Acquire a theoretical focus position value corresponding to a sampling point of the N collection points.

Specifically, the reference tracking curve selected in the foregoing step may be synchronously acquired to obtain a focus position value corresponding to a certain collection point, and the focus position value is used as the theoretical focus position value.

S13. Acquire an actual focus position value when the focus estimation value reaches a maximum under the zoom magnification value corresponding to the collection point, based on a preset autofocus algorithm.

Specifically, in an embodiment of the embodiment of the present invention, the preset autofocus algorithm is a common climbing algorithm, and the focus motor is driven to move to different focus positions under the zoom magnification value corresponding to the collection point. And acquiring image data corresponding to the focus position value; and using the focus position value when the focus estimation value is maximum as the actual focus position value based on the image data and the preset focus estimation value function.

Specifically, under the zoom magnification value corresponding to the collection point, the focus motor is finely adjusted to change the distance between the lens and the captured object, and the lens is stopped based on a certain time or variable step size to obtain the current focus position. One frame image is obtained by acquiring high frequency components of the image data along the horizontal X and the vertical Y, and calculating a focus evaluation value of the frame image based on a preset focus estimation value function. The above operation is repeatedly performed until the focus position value at which the focus evaluation value is maximum is obtained, which is the actual focus position value. For example, in an embodiment of the embodiment of the present invention, the preset focus evaluation value function is:

The x is a horizontal high-frequency component value, and y is a vertical high-frequency component value. The algorithm accumulates all the horizontal x and vertical y high-frequency energy values of the current frame image data obtained from the data image to obtain the Focus on the estimate.

It should be noted that the preset focus estimation function is associated with a scene in which the captured object is located, wherein the scene is identified by a preset scene recognition algorithm. Specifically, in an embodiment of the embodiment of the present invention, a plurality of different scene modes are preset, and each scene mode has a corresponding zoom magnification value, a light intensity value, a focus evaluation value function, a focus motor step size, and The criterion for the conclusion of the focus. By acquiring the light intensity information, the gain, and the zoom magnification value of the current image data, comparing with the zoom magnification value, the gain, and the light intensity information value in the preset plurality of scene modes, selecting the most matching scene mode, and acquiring the scene mode The focus motor step size, the focus evaluation value function, and the focus end judgment criterion.

Further, referring to FIG. 1, the method of an embodiment of the present invention further includes the following steps:

S14, repeating the foregoing steps, respectively acquiring actual focus position values and theoretical focus position values corresponding to the N collection points, and corresponding correction distances of the reference zoom tracking curves on the N collection points, to complete the reference zoom Tracking curve correction.

Specifically, the foregoing step S12 and step S13 are repeatedly performed, respectively acquiring the actual focus position value Focus1 _zoom[N] and the theoretical focus position value Focus2 _zoom[N] corresponding to the N collection points, and according to the actual focus position value. Focus1 _{zoom [N]} and the theoretical focus position value Focus2 _{zoom [N]} calculate the corresponding correction distance focus _{zoom [N]} , then the N correction distances corresponding to the N collection points can be obtained. For example, in an embodiment of the embodiment of the present invention, the calculation algorithm of the corrected distance is:

Focus _zoom[N] =Focus2 _zoom[N] -Focus1 _zoom[N] .

Further, in order to improve the accuracy of the calibration curve, the correction of the reference zoom tracking curve may be implemented not only by the N acquisition points, but also by the linear difference method and the correction of any two adjacent acquisition points. Distance, an actual focus position value of a remaining point between the adjacent two acquisition points on the reference zoom tracking curve is calculated.

For example, one embodiment of the embodiment of the present invention, can be selected from N acquisition points of any adjacent two acquisition points Zoom _[N] and zoom _[N-1], and calculating the corresponding correction distance focus _zoom Focus and _zoom _[N] _[N-1], the calculated correction distance Focus adjacent arbitrary zoom ratio _zoom zoom correspondence between the two collection points are:

Further, according to the reference zoom tracking curve, a theoretical focus position Focus2 _zoom corresponding to an arbitrary zoom magnification value zoom between the adjacent collection points zoom _[N] and zoom _[N-1] is obtained, and then the zoom magnification value zoom is calculated. The actual focus position of Focus1 _zoom :

Focus1 _zoom = focus _zoom +Focus2 _zoom

According to the above method, the actual focus position value of the remaining points between any two adjacent collection points can be obtained, and the specific number of samples can be determined according to actual conditions. Of course, the more the number of samples, the more the corrected zoom tracking curve is obtained. accurate. Further, the existing reference zoom tracking curve is corrected according to the acquired coordinates of at least N (zoom magnification value, actual focus position value).

In summary, the embodiment of the present invention provides a method for correcting a zoom tracking curve, which acquires theoretical focus corresponding to the collected points by selecting N collection points of different zoom magnification values on a theoretical reference zoom tracking curve. Position value; according to the preset autofocus algorithm, the actual focus position value when the focus estimation value reaches the maximum under the zoom magnification value corresponding to the collected points is obtained, based on the actual focus position value and the theoretical focus position value, and between the two Correct the distance to complete the correction of the reference zoom tracking curve. That is, the embodiment of the present invention can obtain the actual zoom tracking curve of each lens itself, thereby ensuring that the actual reference zoom tracking curve that has been corrected is synchronously operated during zooming and auto focusing, so that the entire zoom process image can be focused clearly. . In the embodiment of the present invention, when the actual focus position value is obtained, the focus motor is driven to move to a different focus position under the zoom magnification value corresponding to the collection point, and based on the image data corresponding to the focus position and the preset focus estimation value function. The focus position value when the focus evaluation value is maximum is taken as the actual focus position value, and the focus estimation value function is associated with the scene corresponding to the image data. That is, the embodiment of the present invention can correct the zoom tracking curve of the lens in different scenarios, and improve the accuracy and verification efficiency of the calibration result.

The embodiment of the present invention further provides a zoom tracking curve correction device. Referring to FIG. 5 , the sample module 11 , the theoretical value acquisition module 12 , the actual value acquisition module 13 , and the correction module 14 are provided. . It should be noted that the device according to the embodiment of the present invention is applied to a camera or a camera having a zooming and autofocus function. Of course, the device according to the embodiment of the present invention can also be applied to a mobile phone with a zoom, auto focus function, a PAD, a portable multimedia player (PMP), a TV, and the like. For convenience of description, the embodiment of the present invention is exemplified by a digital camera as an example, but the embodiment does not constitute a limitation on the embodiment of the present invention. The specific functions implemented by each module are specifically disclosed below.

The sampling module 11 is configured to select N collection points on the reference zoom tracking curve, the N collection points corresponding to different zoom magnification values.

It should be noted that it is necessary to provide a pilot description of the zoom tracking curve. It is not difficult to understand that at least two zoom tracking curves with different focus distances are input in advance in the lens. Please refer to FIG. 2. For convenience of description, the focus distances in this solution are 3 meters, 6 meters, 10 meters and infinity respectively. The zoom tracking curve is illustrated as an example. In the coordinate system described in FIG. 2, the horizontal axis represents the zoom magnification value, and the vertical axis represents the focus position value. It can be seen that when the zoom motor position is at a small zoom magnification value, the zoom tracking curves of the four different focus distances are substantially coincident; when the zoom magnification becomes larger, the zoom tracking curves of different focus distances are gradually separated, and the distance difference is more and more different. Big. This shows that when the zoom motor position is at a small zoom magnification value, the motor focus position as the distance of the object from the lens changes. The change is not large, but at high zoom magnification, once the object distance changes greatly, the position of the focus motor also greatly deviates. Therefore, during zooming of the lens, first select a reference zoom tracking curve that best matches the current focus distance.

Specifically, in an embodiment of the embodiment of the present invention, the embodiment of the present invention further includes a reference curve selection module 10. The reference curve selection module 10 is configured to: before the sampling module 11 performs the selection of N collection points on the reference zoom tracking curve, based on the preset first rule, from the pre-stored at least two zoom distances with different zoom distances The reference zoom tracking curve is selected in the tracking curve. Further, the embodiment of the present invention further includes a curve storage module, configured to input at least two focus distances before the reference curve selection module 10 selects the reference zoom tracking curve from the pre-stored zoom tracking curves having different focus distances. Different zoom tracking curves are stored. It is not difficult to understand that the zoom tracking curves having different at least two different focusing distances are input to the imaging lens and stored in advance, for example, may be stored in advance in a storage medium, wherein the storage medium may be a synchronous dynamic random access memory (SDRAM). Multi-chip package (MCP) memory or dynamic random access memory (DRAM).

Specifically, in an embodiment of the embodiment of the present invention, the reference curve selection module 10 may select an initial zoom magnification value and an initial focus focus position value obtained when starting zooming, and the plurality of zoom tracking curves. The closest zoom tracking curve is used as the reference zoom tracking curve. Referring to FIG. 6, the reference curve selection module 10 further includes an initial value acquisition unit 101, a focus value acquisition unit 102, and a curve acquisition unit 103. The initial value acquiring unit 101 is configured to acquire a current zoom motor position and a focus motor position when zooming is started, thereby obtaining an initial zoom magnification value and an initial focus position value;

The focus value obtaining unit 102 is configured to obtain, on each zoom tracking curve, a focus position value corresponding to the initial zoom magnification value;

The curve obtaining unit 103 is configured to select a zoom tracking curve whose focus position value is closest to the initial focus position value as the reference zoom tracking curve.

Specifically, during the zooming of the image capturing lens, the initial value acquiring unit 101 acquires the current zoom motor position and the position of the focus motor, and obtains a corresponding initial zoom magnification value and an initial value focus position value; then the focus value is obtained. The unit 102 acquires a corresponding focus position value from the pre-stored zoom tracking curves of the plurality of different focus distances according to the initial zoom magnification value; then the curve acquisition unit 103 compares the initial focus position value with the obtained plurality of focus position values, and selects The zoom tracking curve corresponding to the closest focus position value is used as the reference zoom tracking curve. Of course, this embodiment is applicable when the magnification value of the lens is greater than a certain value, that is, when the zoom tracking curves of different focus distances are distinct, the embodiment is suitable for zooming from a small zoom magnification value to a large zoom magnification value. In the direction, and the current zoom magnification value is less than a certain value, that is, when the zoom tracking curves of different focus distances are more coincident under the current zoom magnification value, the initial value acquisition unit 101 is also required to select a plurality of initial values for comparison.

Further, after the reference curve selection module 10 selects the reference zoom tracking curve, the sampling module 11 is further required to select N collection points on the reference zoom tracking curve, and the N collection points correspond to different Zoom magnification value.

It is not difficult to understand that under a small zoom magnification value, the zoom tracking curve of different focus distances has a high degree of coincidence, and the sampling module 11 should select fewer acquisition points under a small zoom magnification value; otherwise, a large zoom. Under the magnification value, The zoom tracking curves of different focus distances are gradually separated between each other, so at a large zoom magnification value, the sampling module 11 selects more collection points. That is, the number of collection points selected by the sampling module 11 at different positions on the reference zoom tracking curve is proportional to the zoom odds value corresponding to the current position. For a specific sampling diagram, please refer to FIG. 3. For example, in an embodiment of the present invention, the interval Tx at which the sampling module 11 acquires the acquisition point may be set to an inversely proportional to the zoom magnification value, so that the sampling module 11 calculates the interval according to the algorithm. Value to get the corresponding N collection points. The embodiment is of course only exemplary, which is not limited by the embodiment of the present invention.

Further, referring to FIG. 5, in an embodiment of the apparatus of the embodiment of the present invention, the theoretical value obtaining module 12 is configured to acquire a corresponding theory of a collection point of the N collection points on a reference tracking curve. Focus position value.

Specifically, the theoretical value obtaining module 12 can synchronously follow the selected reference tracking curve in the reference curve selection module 11 to obtain a focus position value corresponding to a certain collection point, and use the focus position value as the theoretical focus position. value.

Further, referring to FIG. 5, in an embodiment of the apparatus of the embodiment of the present invention,

The actual value obtaining module 13 is configured to acquire an actual focus position value when the focus estimation value reaches a maximum under the zoom magnification value corresponding to the collection point based on the preset auto focus algorithm.

Specifically, in an embodiment of the embodiment of the present invention, the preset auto-focusing algorithm is a common climbing algorithm, and the actual value acquiring module 13 drives the focusing at a zoom magnification value corresponding to the collected point. The motor moves to different focus position values, and acquires image data corresponding to the focus position value; based on the image data and the preset focus estimation value function, the focus position value when the focus estimation value is maximum is taken as the actual focus position value.

Specifically, the actual value obtaining module 13 drives the focus motor to finely adjust the distance between the lens and the captured object under the zoom magnification value corresponding to the collection point, and stops the time based on a certain time or variable step size. The lens acquires a frame image of the current focus position, acquires high frequency components of the image data along the horizontal X and the vertical Y, and calculates a focus evaluation value of the frame image based on a preset focus estimation value function. The above operation is repeatedly performed until the actual value acquisition module 13 acquires the focus position value when the focus evaluation value is maximum, and the focus position value is the actual focus position value. For example, in an embodiment of the embodiment of the present invention, the preset focus evaluation value function is:

It should be noted that the preset focus estimation function is associated with a scene in which the captured object is located, wherein the scene is identified by a preset scene recognition algorithm. Specifically, in an embodiment of the embodiment of the present invention, a plurality of different scene modes are preset, and each scene mode has a corresponding zoom magnification value, a light intensity value, a focus evaluation value function, a focus motor step size, and The criterion for the conclusion of the focus. The actual value obtaining module 13 compares the zoom intensity value, the gain, and the light intensity information value in the preset plurality of scene modes by acquiring the light intensity information, the gain, and the zoom magnification value of the current image data, and selects the most matching scene. The mode acquires a focus motor step size, a focus evaluation value function, and a focus end judgment criterion in the scene mode.

Further, referring to FIG. 5, in an embodiment of the apparatus of the embodiment of the present invention, a correction module 14 is further included. The correction module 14 is configured to repeatedly invoke the foregoing modules to perform corresponding operations, respectively acquiring actual focus position values and theoretical focus position values corresponding to the N collection points, and the reference zoom tracking curves are in the N collections. The corresponding correction distance is clicked to complete the correction of the reference zoom tracking curve.

Specifically, the correction module 14 repeatedly invokes the foregoing theoretical value acquisition module 12 and the actual value acquisition module 13 to acquire the actual focus position values corresponding to the N collection points, Focus1 _zoom _[N] and the theoretical focus position value Focus2 _{zoom. [N]} , according to the actual focus position value Focus1 _{zoom [N]} and the theoretical focus position value Focus2 _{zoom [N]} calculate the corresponding correction distance focus _{zoom [N]} , the N correction distances corresponding to the N collection points can be obtained. For example, in an embodiment of the embodiment of the present invention, the calculation algorithm of the corrected distance is:

Focus _zoom[N] =Focus2 _zoom[N] -Focus1 _zoom[N] .

Further, in order to improve the accuracy of the calibration curve, the correction module 14 may implement the correction of the reference zoom tracking curve not only by the N acquisition points, but also the linear difference method and any adjacent two. The corrected distance of the collected points is calculated, and the actual focus position value of the remaining points between the adjacent two collection points on the reference zoom tracking curve is calculated.

For example, in an embodiment of the embodiment of the present invention, the correction module 14 may select any two adjacent collection points zoom _[N] and zoom _[N-1] from the N collection points, and calculate the corresponding _zoom correction distance Focus Focus and _zoom _[N] _[N-1], corresponding to the adjacent zoom Focus correction distance calculated zoom ratio _zoom any point between the two values is acquired:

Further, the correction module 14 acquires a theoretical focus position Focus2 _zoom corresponding to an arbitrary zoom magnification value zoom between the adjacent collection points zoom _[N] and zoom _[N-1] according to the reference zoom tracking curve, and then calculates the The zoom focus value zoom corresponds to the actual focus position Focus1 _zoom :

Focus1 _zoom = focus _zoom +Focus2 _zoom

According to the embodiment described in the foregoing embodiment, the correction module 14 can obtain the actual focus position values of a plurality of remaining points between any two adjacent collection points, and the specific number of samples can be determined according to actual conditions. The more the number of samples, the more accurate the corrected zoom tracking curve. Further, the existing reference zoom tracking curve is corrected according to the acquired coordinates of at least N (zoom magnification value, actual focus position value).

In summary, the embodiment of the present invention provides a calibration apparatus for a zoom tracking curve, which selects N collection points of different zoom magnification values on a theoretical reference zoom tracking curve by the sampling module 11 and obtains a module by a theoretical value. 12: acquiring the theoretical focus position value corresponding to the collection points; the actual value acquisition module 13 further acquires the actual focus position value when the focus estimation value reaches the maximum under the zoom magnification value corresponding to the collection points according to the preset auto focus algorithm, and finally passes The correction module 14 completes the correction of the reference zoom tracking curve based on the actual focus position value and the theoretical focus position value, and the corrected distance between the two. That is, the embodiment of the present invention can obtain the actual zoom tracking curve of each lens itself, thereby ensuring that the actual reference zoom tracking curve that has been corrected is the same in the subsequent zooming and autofocusing. The step is run so that the entire zoom process image can be focused clearly.

In the embodiment of the present invention, when the actual focus position value is obtained, the focus motor is driven to move to a different focus position under the zoom magnification value corresponding to the collection point, and based on the image data corresponding to the focus position and the preset focus estimation value function. The focus position value when the focus evaluation value is maximum is taken as the actual focus position value, and the focus estimation value function is associated with the scene corresponding to the image data. That is, the embodiment of the present invention can correct the zoom tracking curve of the lens in different scenarios, and improve the accuracy and verification efficiency of the calibration result.

In the description provided herein, numerous specific details are set forth. However, it is understood that the embodiments of the invention may be practiced without these specific details. In some embodiments, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of the specification.

While some of the exemplary embodiments of the present invention have been shown in the foregoing embodiments of the embodiments of the invention The scope of the embodiments of the invention is defined by the claims and their equivalents.

For the device implementation, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiment.

The algorithms and displays provided herein are not inherently related to any particular computer, virtual system, or other device. Various general purpose systems can also be used with the teaching based on the teachings herein. The structure required to construct such a system is apparent from the above description. Moreover, embodiments of the invention are not directed to any particular programming language. It is to be understood that the description of the embodiments of the invention herein described herein may be

In the description provided herein, numerous specific details are set forth. However, it is understood that the embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of the description.

Similarly, in order to simplify the present disclosure and to help understand one or more of the various inventive aspects, in the above description of the exemplary embodiments of the embodiments of the present invention, various features of the embodiments of the present invention are sometimes grouped together A single embodiment, figure, or description thereof. However, the method disclosed is not to be interpreted as reflecting the intention that the claimed embodiments of the invention are claimed. Rather, as the following claims reflect, inventive aspects reside in less than all features of the single embodiments disclosed herein. Therefore, the claims following the specific embodiments are hereby explicitly incorporated into the specific embodiments, and each of the claims as a separate embodiment of the embodiments of the invention.

Those skilled in the art will appreciate that the modules in the devices of the embodiments can be adaptively changed and placed in one or more devices different from the embodiment. The modules or units or components of the embodiments may be combined into one module or unit or component, and further they may be divided into a plurality of sub-modules or sub-units or sub-components. In addition to such features and/or at least some of the processes or units being mutually exclusive, any combination of the features disclosed in the specification, including the accompanying claims, the abstract and the drawings, and any methods so disclosed, or All processes or units of the device are combined. Each feature disclosed in this specification (including the accompanying claims, the abstract and the drawings) may be replaced by alternative features that provide the same, equivalent or similar purpose.

Moreover, those skilled in the art will appreciate that, although some embodiments described herein include certain features that are included in other embodiments and not in other features, combinations of features of the different embodiments are implied in the embodiments of the invention. Different embodiments are formed within the scope of the invention. For example, in the following claims, any one of the claimed embodiments can be used in any combination.

Various component embodiments of embodiments of the invention may be implemented in hardware, or in a software module running on one or more processors, or in a combination thereof. Those skilled in the art will appreciate that a microprocessor or digital signal processor (DSP) may be used in practice to implement some or all of the functionality of some or all of the components of an asynchronous login device in accordance with an embodiment of the present invention. Embodiments of the invention may also be implemented as a device or device program (e.g., a computer program and a computer program product) for performing some or all of the methods described herein. Such a program implementing an embodiment of the invention may be stored on a computer readable medium or may be in the form of one or more signals. Such signals may be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

For example, FIG. 7 illustrates a terminal device that can implement a method of correcting a zoom tracking curve according to an embodiment of the present invention. The terminal device conventionally includes a processor 710 and a computer program product or computer readable medium in the form of a memory 720. Memory 720 can be an electronic memory such as a flash memory, EEPROM (Electrically Erasable Programmable Read Only Memory), EPROM, hard disk, or ROM. Memory 720 has a memory space 730 for program code 731 for performing any of the method steps described above. For example, storage space 730 for program code may include various program code 731 for implementing various steps in the above methods, respectively. The program code can be read from or written to one or more computer program products. These computer program products include program code carriers such as hard disks, compact disks (CDs), memory cards or floppy disks. Such a computer program product is typically a portable or fixed storage unit as described with reference to FIG. The storage unit may have a storage section, a storage space, and the like arranged similarly to the storage 720 in the terminal device of FIG. The program code can be compressed, for example, in an appropriate form. Typically, the storage unit includes computer readable code 731', i.e., code readable by a processor, such as 710, that when executed by the terminal device causes the terminal device to perform each of the methods described above step.

It should be noted that the above-described embodiments are illustrative of the embodiments of the present invention and are not intended to limit the embodiments of the present invention, and those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as a limitation. The word "comprising" does not exclude the presence of the elements or steps that are not recited in the claims. The word "a" or "an" Embodiments of the invention may be implemented by means of hardware comprising several distinct elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means can be embodied by the same hardware item. The use of the words first, second, and third does not indicate any order. These words can be interpreted as names.

In addition, it should be noted that the language used in the present specification has been selected for the purpose of reading and teaching, and is not intended to be construed as limiting or limiting the subject matter of the embodiments of the present invention. Therefore, many modifications and changes will be apparent to those skilled in the art without departing from the scope of the invention. The disclosure of the embodiments of the present invention is intended to be illustrative and not restrictive, and the scope of the embodiments of the invention is defined by the appended claims.

Claims

A method for correcting a zoom tracking curve, comprising:

N acquisition points are selected on the reference zoom tracking curve, and the N collection points correspond to different zoom magnification values;

Obtaining a theoretical focus position value corresponding to a sampling point of the N collection points on the reference zoom tracking curve;

Obtaining an actual focus position value when the focus estimation value reaches a maximum at a zoom magnification value corresponding to the collection point based on a preset auto focus algorithm;

Repeating the above steps, respectively acquiring actual focus position values and theoretical focus position values corresponding to the N collection points, and corresponding correction distances of the reference zoom tracking curves on the N collection points, to complete the reference zoom tracking curve. Correction.
The method according to claim 1, wherein the number of collection points selected at different positions on the reference zoom tracking curve is proportional to the zoom magnification value corresponding to the current position.
The method of claim 1 wherein said corrected distance is a difference between said theoretical focus position value and an actual focus position value.
The method according to claim 1, wherein the acquiring the actual focus position value and the theoretical focus position value corresponding to the N collection points respectively, and the reference zoom tracking curve corresponding to the N collection points The steps of correcting the distance also include:

Using the linear difference method and the corrected distance of any two adjacent acquisition points, the actual focus position value of the remaining points between the adjacent two collection points on the reference zoom tracking curve is calculated.
The method according to claim 1, wherein the step of selecting N acquisition points on the reference zoom tracking curve, the N acquisition points corresponding to different zoom magnification values, further comprising:

Based on the first rule of the preset, the reference zoom tracking curve is selected from the pre-stored zoom tracking curves of at least two different focus distances.
The method according to claim 5, wherein the step of selecting the reference zoom tracking curve from the pre-stored zoom tracking curves having different focus distances according to the preset first rule further comprises:

Enter at least two zoom tracking curves with different focus distances and store them.
The method of claim 5, wherein the step of selecting a reference zoom tracking curve from the pre-stored at least two zoom tracking curves having different focus distances according to the preset first rule further comprises:

The initial zoom magnification value, the initial focus position value acquired at the start of zooming, and the zoom tracking curve are matched, and the closest one zoom tracking curve is selected as the reference zoom tracking curve.
The method according to claim 7, wherein the initial zoom magnification value, the initial focus position value acquired at the start of zooming, and the zoom tracking curve are matched, and the closest zoom tracking curve is selected as the reference zoom tracking curve. The steps also include:

When the zooming is started, the current zoom motor position and the focus motor position are acquired, thereby obtaining an initial zoom magnification value and an initial focus position value;

Obtaining a focus position value corresponding to the initial zoom magnification value on each zoom tracking curve;

Select a zoom tracking curve whose focus position value is closest to the initial focus position value as the reference zoom track line.
The method according to claim 1, wherein in the step of acquiring an actual focus position value when the focus estimation value reaches a maximum under the zoom magnification value corresponding to the collection point based on the preset auto focus algorithm, include:

And driving the focus motor to move to different focus position values under the zoom magnification value corresponding to the collection point, and acquiring image data corresponding to the focus position value;

Based on the image data and the preset focus estimation value function, the focus position value at which the focus evaluation value is maximum is taken as the actual focus position value.
A calibration device for a zoom tracking curve, comprising:

a sampling module, configured to select N collection points on the reference zoom tracking curve, the N collection points corresponding to different zoom magnification values;

a theoretical value obtaining module, configured to acquire a theoretical focus position value corresponding to a sampling point of the N collection points on the reference zoom tracking curve;

An actual value obtaining module, configured to acquire, according to a preset autofocus algorithm, an actual focus position value when a focus estimation value reaches a maximum under a zoom magnification value corresponding to the collection point;

a correction module, configured to repeatedly invoke the foregoing modules to perform corresponding operations, respectively acquiring an actual focus position value and a theoretical focus position value corresponding to the N collection points, and correspondingly the reference zoom tracking curve on the N collection points Correct the distance to complete the correction of the reference zoom tracking curve.
A computer program comprising computer readable code causing the terminal device to perform a correction method of a zoom tracking curve according to any one of claims 1-9 when the computer readable code is run on a terminal device .
A computer readable medium storing the computer program of claim 11.