WO2017107770A1

WO2017107770A1 - Method and device for correcting zoom tracking curve

Info

Publication number: WO2017107770A1
Application number: PCT/CN2016/108870
Authority: WO
Inventors: 林铁楠
Original assignee: 北京奇虎科技有限公司; 奇智软件（北京）有限公司
Priority date: 2015-12-23
Filing date: 2016-12-07
Publication date: 2017-06-29
Also published as: CN105554387A

Abstract

The present invention relates to the technical field of camera surveillance, and particularly relates to a method and device for correcting a zoom tracking curve. The method comprises: according to a zoom direction and corresponding preset rules thereof, selecting a reference zoom tracking curve from at least two pre-stored zoom tracking curves with different focus distances, thereby driving a zoom motor and a focus motor to rotate synchronously according to the reference zoom tracking curve; selecting N number of collection points corresponding to different zoom values on the reference zoom tracking curve; on the basis of a preset auto-focus algorithm, respectively obtaining an actual focus position value of any collection point from among the N number of collection points when a focus estimate value, at the corresponding zoom value, reaches a maximum value; according to the obtained actual focus position values corresponding to the N number of collection points, finishing correcting the reference zoom tracking curve. Thus, the present application is able to obtain the actual zoom tracking curve of each lens, and ensure that the subsequent zoom and auto focus are carried out synchronously with the corrected actual reference zoom tracking curve, such that images are focused and clear throughout the entire zoom process.

Description

Method and device for correcting zoom tracking curve

The present application claims priority to Chinese Patent Application No. 201510982783.2, entitled "Correction Method and Apparatus for Zoom Tracking Curve", filed on December 23, 2015, the entire contents of which are incorporated herein by reference. In the application.

Technical field

The present application 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 the zoom process, zoom tracking is required to synchronize the focus lens according to the position of the zoom lens. Change so that the image can be focused clearly.

Usually, the lens manufacturer will provide a fixed ideal zoom tracking curve corresponding to the lens, which is convenient for the camera to realize zoom tracking and auto focus according to the zoom tracking curve. However, when the theoretical reference zoom tracking curve is selected, 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, different focus distances The zoom tracking curves are gradually separated, and the distances are getting larger and larger. Therefore, the zoom motor is switched from a small magnification to a large magnification, or from a large magnification to a small magnification. In both cases, due to the difference in the zoom tracking curve, the rules for selecting the reference zoom tracking curve should be different accordingly. The selection accuracy of the reference zoom tracking curve is described. However, in the prior art, when the reference zoom tracking curve is selected, the processing is not distinguished for the two different zoom directions.

Moreover, due to the individual differences of the lens, when using a certain lens, it is necessary to adjust and confirm the zooming of each lens and the optical reference position of the focus to obtain the most suitable zoom tracking curve, if the fixed ideal reference is used. When the zoom tracking curve is used for zoom tracking, the image may have different degrees of blur. Therefore, before or during the lens zoom tracking process, if the curve can be synchronized according to the actual zooming of each lens itself, the entire zoom process image can be focused clearly. So how to get the actual zoom tracking curve of each lens is a technical problem to be solved question.

Summary of the invention

The purpose of the present application 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 this goal, the present application adopts the following technical solutions:

The application provides a method for correcting a zoom tracking curve, which includes:

According to the zoom direction and the corresponding preset rule, the reference zoom curve is selected from the pre-stored zoom curves with different focus distances to drive the zoom motor and the focus motor according to the reference zoom curve. Synchronous rotation

Selecting N collection points corresponding to different zoom magnification values on the reference zoom tracking curve;

Obtaining, according to a preset auto-focusing algorithm, an actual focus position value when the focus estimation value reaches a maximum value at a corresponding zoom magnification value of any one of the N collection points;

The correction of the reference zoom tracking curve is completed according to the obtained actual focus position values corresponding to the N collection points.

The application also provides a calibration device for a zoom tracking curve, which includes:

a reference curve selection module, configured to select a reference zoom curve from the pre-stored at least two zoom tracking curves with different focus distances according to the zoom direction and the corresponding preset rule, according to the reference zoom curve Driving the zoom motor and the focus motor to rotate synchronously;

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

An actual value obtaining module, configured to acquire, according to a preset auto-focusing algorithm, an actual focus position value when a focus estimation value of the N collection points reaches a maximum value at a corresponding zoom ratio value;

And a correction module, configured to complete the correction of the reference zoom tracking curve according to the obtained actual focus position values corresponding to the N collection points.

The present application also provides a computer program comprising computer readable code that, when executed on an electronic device, causes the electronic device to perform a method of correcting a zoom tracking curve of the sacred.

The application also provides a computer readable medium in which the computer program described above is stored.

Compared with the prior art, the application has the following advantages:

1. The present application provides a method and apparatus for correcting a zoom tracking curve according to the current zoom The direction and the preset rule corresponding to the zoom direction, the reference zoom curve is selected from the pre-stored plurality of theoretical zoom curves, and N different zoom ratio values are selected on the theoretical reference zoom curve. 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, and the correction of the reference zoom tracking curve is completed. That is, the present application can select a reference zoom tracking curve by using a preset rule corresponding to the zoom direction for the current zoom direction, and obtain the actual focus position of the collection point by auto focus, and then obtain the actual of each lens itself by correction. Zooming the tracking curve to ensure that the actual reference zoom tracking curve that has been corrected is synchronized in the subsequent zoom and auto focus, ensuring that the entire zoom process image can be focused clearly;

2. In the present application, when the actual focus position value is obtained, the focus motor is driven 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. A 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 present application can correct the zoom tracking curve of the lens in different scenarios, and improve the accuracy and verification efficiency of the calibration result.

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

DRAWINGS

Various other advantages and benefits will become apparent to those skilled in the art from a The drawings are only for the purpose of illustrating the preferred embodiments and are not intended to be limiting. Throughout the drawings, the same reference numerals are used to refer to the same parts. In the drawing:

1 is a flowchart of a process of an embodiment of a zoom tracking curve correction method in an embodiment of the present application;

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

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

4 is a structural block diagram of an embodiment of a zoom tracking curve correction apparatus in an embodiment of the present application;

Figure 5 schematically shows a block diagram of an electronic device for performing the method according to the present application;

Figure 6 shows schematically a procedure for maintaining or carrying a method according to the present application. The storage unit of the code.

Specific embodiment

The present application is further described in the following with reference to the drawings and exemplary embodiments, which are illustrated in the accompanying drawings, in which the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions. . The embodiments described below with reference to the accompanying drawings are intended to be illustrative only, and are not to be construed as limiting. Further, if a detailed description of a known technique is unnecessary for the features of the present application, it will be omitted.

The singular forms "a", "an", "the" It is to be understood that the phrase "comprise" or "an" 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 commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. 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 described in the present application is a process of zooming and autofocusing when applied to a camera or a camera to capture an image. Of course, the method described in the present application 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.

Referring to FIG. 1 , it is a flowchart of an embodiment of a method for correcting a zoom tracking curve according to the present application, which includes the steps of:

S11, according to the zoom direction and the corresponding preset rule, select a reference zoom tracking curve from the pre-stored at least two zoom tracking curves with different focus distances, according to the reference zoom curve The drive zoom motor and the focus motor rotate in synchronization.

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 focus distances in the present scheme are 3 meters, 6 meters, 10 meters, and infinity respectively. The zoom tracking curve is taken as an example. 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. The distance is getting bigger and bigger. This shows that when the zoom motor position is at a small zoom factor value, the focus position of the motor does not change much as the distance of the object from the lens changes, but at a high zoom ratio, the object distance changes greatly, focusing. The motor position also has a large deviation. Therefore, in the lens zooming process, first select a reference zoom tracking curve that best matches the current focus distance.

It is not difficult to understand that the at least two zoom tracking curves having different focus distances are input to the image pickup lens in advance and stored, 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, referring to the different characteristics of the aforementioned reference zoom tracking curve, it is not difficult to know whether the zoom motor is switched from a small magnification to a large magnification or a large magnification to a small magnification. In both cases, due to the characteristics of the zoom tracking curve, the selection is selected. The rules of the reference zoom tracking curve should also be different to ensure the accuracy of the selection of the reference zoom tracking curve. Therefore, in this embodiment, it is also required to determine a selection rule of the corresponding reference zoom tracking curve according to the zoom direction of the current zoom motor.

Specifically, in an embodiment of the present application, when the zoom direction of the current zoom motor is a small magnification steering large magnification, the focus motor is driven to obtain a current zoom magnification value corresponding to the focus position in each zoom tracking curve. And the corresponding focus evaluation value, the zoom tracking curve at which the focus position having the largest focus evaluation value is determined is the reference zoom tracking curve.

It is not difficult to understand that it can be seen from FIG. 1 that when the variable power motor is in the small magnification range, the corresponding multiple zoom tracking curves of different different focus distances substantially coincide, that is, the same zoom magnification value is at different focus distances. The focus position corresponding to the zoom tracking curve is almost the same, so in the zoom direction, the current focus motor position and the zoom motor position are obtained, and the current focus position value and the current zoom ratio are obtained. The rate value is then obtained by acquiring the current zoom magnification value in the corresponding focus position in each zoom tracking curve, but at a small magnification, the focus position cannot be compared with the current focus position, so the method cannot obtain the reference zoom tracking. curve. Specifically, in the present application, after the focus motor is driven to obtain the focus position of the current zoom magnification value in each zoom tracking curve, the focus evaluation value of each focus position is calculated based on the preset focus estimation value function. The zoom tracking curve at which the focus position at which the focus evaluation value is the largest is determined as the reference zoom tracking curve.

Specifically, in an embodiment of the present application, when the zoom direction of the current zoom motor is a large magnification to a small magnification, the current focus position of the focus motor is acquired; and then the current zoom ratio value is acquired in each zoom tracking. The corresponding focus position in the curve determines that the zoom tracking curve whose focus position is closest to the current focus position is the reference zoom tracking curve.

It is not difficult to understand that, as can be seen from FIG. 2, when the variable power motor is in the large magnification range, the zoom tracking curves of different focus distances are gradually separated, and the distance difference is larger and larger. That is, the same zoom magnification value has a large difference in the focus position corresponding to the zoom tracking curve of different focus distances. Therefore, in the zoom direction, the current focus motor position and the zoom motor position are obtained, and the current focus position value and current change are obtained. The multiplier value is then obtained by obtaining the current zoom magnification value in the corresponding focus position in each zoom tracking curve, and then comparing the focus position to the current focus position to determine the closest zoom point of the focus position to the current focus position. The tracking curve is the reference zoom tracking curve.

It is not difficult to understand that the present application can select a reference zoom tracking curve by using a preset rule corresponding to the zoom direction for the current zoom direction, thereby ensuring the accuracy of the zoom tracking curve selection.

Further, referring to FIG. 1, in the method described in the present application, the method further includes the following steps:

S12, selecting N acquisition points corresponding to different zoom magnification values on the reference zoom tracking curve.

It is not difficult to understand that the closest zoom tracking curve is selected as the reference zoom tracking curve in the foregoing steps. Further, 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 less acquisition points should be selected under a small zoom magnification value; conversely, at a large zoom ratio Under the value, the zoom tracking curves of different focus distances are gradually separated, so under the large zoom magnification value, more collection points are selected. That is, the collection points selected in different regions on the reference zoom curve The quantity is proportional to the value of the zoom ratio corresponding to the center position point of the current area. For the specific sampling diagram, please refer to FIG. 3. For example, in an embodiment of the present application, the interval Tx of the collection point may be set to an inversely proportional to the value of the magnification change of the center of the region, so that the processor in the lens obtains the interval value calculated by the algorithm. Corresponding to a certain number of collection points. The embodiment is of course only exemplary, which is not limited in this application.

It should be noted that, in the present application, the reference zoom tracking curve may be divided into different regions according to the magnitude of the zoom magnification value. For example, the reference zoom tracking curve is divided into a small magnification region, a medium magnification region, and a large magnification region in the present application. By selecting the first magnification threshold and the second magnification threshold on the reference zoom tracking curve, when the magnification value is less than the first magnification threshold, determining that it is in the small magnification region; when the magnification value is greater than the second magnification threshold, determining In the large rate area; the others are the medium rate area.

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

S13. Acquire, according to a preset autofocus algorithm, an actual focus position value when the focus estimation value reaches a maximum value at the corresponding zoom magnification value of any one of the N collection points.

Specifically, in an embodiment of the present application, the preset autofocus algorithm is a common climbing algorithm, and the focus motor is driven 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; 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 to obtain the current focus position. A frame image of the time, obtains 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 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 present application, the preset focus evaluation value function is:

The x refers to the horizontal high-frequency component value, and y refers to the vertical high-frequency component value. The algorithm accumulates the high-frequency energy values of all the horizontal x and vertical y of the current frame image data obtained from the data image. Go to the focus 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 present application, a plurality of different scene modes are preset, and each of the scene modes has a corresponding zoom magnification value, a light intensity value, a focus evaluation value function, a focus motor step size, and a focus. The judgment criteria for the end. By acquiring the light intensity information, the gain, and the zoom magnification value of the current image data, comparing with the variable 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 Focus motor step size, focus evaluation value function, and focus end judgment criteria in mode.

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

S14. Perform correction of the reference zoom tracking curve according to the obtained actual focus position values corresponding to the N collection points.

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 collection points, but also by the linear difference method and the correction of any two adjacent pole points. Distance, calculating an actual focus position value of the remaining points between the adjacent two collection points on the reference zoom tracking curve.

For example, in the method of the present application, it is also required to acquire a theoretical focus position value corresponding to any of the N collection points on the reference zoom tracking curve, and calculate the theoretical focus position value and the actual focus position value. Correcting the distance between the two, and then using the linear difference method and the corrected distance of any two adjacent acquisition points, calculating the actual focus position value of the remaining points between the adjacent two collection points on the reference zoom tracking curve .

Specifically, in an exemplary embodiment of the present application, the actual focus position value Focus1 _zoom[N] and the theoretical focus position value Focus2 _zoom[N] corresponding to the N collection points are respectively acquired, 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 one embodiment of the present application, the algorithm for calculating the corrected distance is:

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

Further, any two adjacent collection points zoom _[N] and zoom _[N-1] may be selected from the N collection points, and the corresponding correction distances focus _{zoom [N]} and focus _zoom _[N-1] may be calculated. _], the calculated correction distance Focus arbitrary _zoom magnification corresponding to the zoom magnification value between the two adjacent points are collected:

Further, according to the reference zoom tracking curve, the theoretical focus position Focus2 _zoom corresponding to the arbitrary zoom magnification value zoom between the adjacent collection points zoom _[N] and zoom _[N-1] is obtained, and then the zoom ratio is calculated. The actual focus position corresponding to the value zoom is Zoom1 _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 the actual situation. Of course, the more the number of samples, the corrected zoom tracking curve. The more precise. Further, the existing reference zoom tracking curve is corrected according to the acquired coordinates of at least N (variable magnification value, actual focus position value).

In summary, the present application provides a method for correcting a zoom tracking curve, and selecting a reference variable from a plurality of pre-stored theoretical zoom tracking curves according to a current zoom direction and a preset rule corresponding to the zoom direction. The tracking curve is multiplied, and N collection points of different zoom magnification values are selected on the theoretical reference zoom tracking curve; and the focus estimation values of the zoom magnification values corresponding to the collected points are obtained according to the preset autofocus algorithm. The actual focus position value at the maximum is reached to complete the correction of the reference zoom tracking curve. That is, the present application can select a reference zoom tracking curve by using a preset rule corresponding to the zoom direction for the current zoom direction, and obtain the actual focus position of the collection point by auto focus, and then obtain the actual of each lens itself by correction. The zoom tracking curve is used to ensure that the actual reference zoom tracking curve that has been corrected is synchronized in the subsequent zoom and auto focus, ensuring that the entire zoom process image can be focused clearly.

Based on the modular thinking of the computer, the present application also provides a zoom tracking curve correction device. Referring to FIG. 4, the reference curve selection module 11, the sampling module 12, the actual value acquisition module 13, and the correction module 14 are included. It should be noted that the device described in the present application is applied to a camera or a camera having a zooming and autofocus function. Of course, the device described in the present application 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 application exemplifies a specific embodiment thereof by using a digital camera as an example, but the embodiment does not constitute a limitation of the present application. The following specifically reveals the various modules. The specific function now.

The reference curve selection module 11 is configured to select a reference zoom tracking curve from the pre-stored at least two zoom tracking curves with different focus distances according to the zoom direction and the corresponding preset rule, according to the reference variable The double tracking curve drives the zoom motor and the focus motor to rotate synchronously.

Specifically, referring to the different characteristics of the aforementioned reference zoom tracking curve, it is not difficult to know whether the variable power motor shifts from a small magnification to a large magnification or a large magnification to a small magnification. In both cases, due to the characteristics of the zoom tracking curve, The rules for selecting the reference zoom tracking curve by the reference curve selection module 11 should also be different, so as to ensure the selection precision of the reference zoom tracking curve. Therefore, in the embodiment, the reference curve selection module 11 further needs to determine a selection rule of the corresponding reference zoom tracking curve according to the zoom direction of the current zoom motor.

Specifically, in an embodiment of the present application, the reference curve selection module 11 further includes a first selection unit. The first selecting unit is configured to drive the focus motor to obtain a current zoom magnification value corresponding to a focus position in each zoom tracking curve when the zoom direction of the current zoom motor is a small magnification to a large magnification. Focusing on the evaluation value to determine the focus position where the focus evaluation value is the largest The zoom tracking curve is the reference zoom tracking curve.

It is not difficult to understand that, as can be seen from FIG. 2, when the variable power motor is in the small magnification range, the corresponding multiple zoom tracking curves of different different focus distances substantially coincide, that is, the same zoom magnification value is at different focus distances. The focus position corresponding to the zoom tracking curve is almost the same, so in the zoom direction, the current focus motor position and the zoom motor position are obtained, the current focus position value and the current zoom ratio value are obtained, and then the current zoom ratio value is obtained. The corresponding focus position in each zoom tracking curve, but at a small magnification, the focus position cannot be compared with the current focus position, so the reference zoom curve cannot be obtained in this way. Specifically, in the present application, after the first selecting unit obtains the focus position of the current zoom magnification value in each zoom tracking curve by driving the focus motor, each focus is calculated based on the preset focus estimation value function. The focus evaluation value of the position, so that the zooming curve in which the first selecting unit determines the focus position at which the focus evaluation value is the largest is the reference zoom tracking curve.

Specifically, in an embodiment of the present application, the reference curve selection module further includes a second selection unit. The second selecting unit is configured to acquire a current focus position of the focus motor when the zoom direction of the current zoom motor is a large magnification to a small magnification; and then obtain a current zoom magnification value corresponding to each zoom tracking curve. The focus position, the zoom tracking curve that determines the closest focus position to the current focus position is the reference zoom tracking curve.

It is not difficult to understand that, as can be seen from FIG. 2, when the variable power motor is in the large magnification range, the zoom tracking curves of different focus distances are gradually separated, and the distance difference is larger and larger. That is, the same zoom factor value has a large difference in the focus position corresponding to the zoom tracking curve of different focus distances, so in the zoom direction, the second selecting unit acquires the current focus motor position and the zoom motor position, and obtains the current Focusing the position value and the current zoom magnification value, and then obtaining the current zoom magnification value in the corresponding focus position in each zoom tracking curve, and the second selecting unit compares the focus position to the current focus position by comparing the focus position, The zoom tracking curve that determines the closest focus position to the current focus position is the reference zoom tracking curve.

It is not difficult to understand that the reference curve selection module 11 of the present application can select the reference zoom tracking curve by using a preset rule corresponding to the zoom direction for the current zoom direction, thereby ensuring the accuracy of the zoom tracking curve selection. .

Further, the sampling module 12 is configured to select N pairs on the reference zoom tracking curve. Should be at the collection point of different zoom ratio values.

It is not difficult to understand that the closest one of the reference curve selection modules 11 is selected as the reference zoom tracking curve. Further, the sampling module 12 further needs 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 the sampling module 12 should select fewer acquisition points under a small zoom magnification value; Under the large zoom ratio value, the zoom tracking curves of different focus distances are gradually separated, so the sampling module 12 selects more collection points under the large zoom magnification value. That is, the number of collection points selected in different regions on the reference zoom tracking curve is proportional to the value of the zoom magnification corresponding to the central position point of the current region. For a specific sampling diagram, please refer to FIG. For example, in an embodiment of the present application, the sampling module 12 may set an interval Tx of the collection point to an algorithm that is inversely proportional to the value of the magnification of the center of the region, so that the processor in the lens calculates according to the algorithm. The interval value is used to obtain a corresponding number of collection points. The embodiment is of course only exemplary, which is not limited in this application.

It should be noted that the sampling module 12 in the present application may divide the reference zoom tracking curve into different regions according to the magnitude of the zoom ratio value. For example, the reference zoom tracking curve is divided into a small magnification region, a medium magnification region, and a large magnification region in the present application. The sampling module 12 selects a first magnification threshold and a second magnification threshold on the reference zoom tracking curve, and when the magnification value is less than the first magnification threshold, the sampling module 12 determines that it is in a small magnification region; When the value is greater than the second magnification threshold, the sampling module 12 determines that it is in the large magnification region; the others are the medium magnification region.

The actual value obtaining module 13 is configured to acquire, according to a preset auto-focusing algorithm, an actual focus position value when the focus estimation value of the N points of the N collection points reaches a maximum value under the corresponding zoom ratio value.

Specifically, in an embodiment of the present application, the preset auto-focusing algorithm is a common climbing algorithm, and the actual value acquiring module 13 drives the focusing motor under the zoom factor value corresponding to the collecting point. Moving to different focus position values, and acquiring image data corresponding to the focus position value; the actual value acquisition module 13 based on the image data and a preset focus estimation value function, The focus position value at which the estimated 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 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 then the actual value acquisition module 13 calculates the frame image based on the preset focus estimation value function. Focus evaluation value. 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 present application, 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 present application, a plurality of different scene modes are preset in the camera lens, and each of the scene modes has a corresponding zoom magnification value, a light intensity value, a focus evaluation value function, and a focus. Motor step size and criteria for judging the end of focus. The actual value obtaining module 13 compares the light intensity information, the gain, and the zoom magnification value of the current image data with the zoom ratio value, the gain, and the light intensity information value in the preset plurality of scene modes to select the best match. The scene mode acquires the focus motor step size, the focus evaluation value function, and the focus end judgment criterion in the scene mode.

Further, the correction module 14 is configured to complete the correction of the reference zoom tracking curve according to the obtained actual focus position values corresponding to the N collection points.

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 collection points, but also the linear difference method and any adjacent two. The correction distance of the poles 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, the device of the present application further includes an actual value acquisition module and a second sampling unit. The actual value obtaining module is configured to acquire any one of the N collection points in a reference zoom tracking A corresponding theoretical focus position value on the curve, and a correction distance between the theoretical focus position value and the actual focus position value is calculated. And calculating, by the second sampling unit, the actual focus position of the remaining points between the adjacent two collection points on the reference zoom tracking curve by using the linear difference method and the corrected distance of any two adjacent collection points. value.

Specifically, in an exemplary embodiment of the present application, the actual value obtaining module 13 and the theoretical value acquiring module respectively acquire the actual focus position value Focus1 _{zoom [N]} and the theoretical focus position value Focus2 corresponding to the N collection points. _{zoom [N],} and acquires the actual focusing module according to the _zoom position value Focus1 _[N] and the theoretical value obtained by the focus position of the _zoom Focus2 are theoretical values corresponding to _[N] calculated correction distance focus _{zoom [N],} to obtain the N N correction distances corresponding to the collection points. For example, in one embodiment of the present application, the algorithm for calculating the corrected distance is:

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

Further, the second sampling unit may select any two adjacent collection points zoom _[N] and zoom _[N-1] from the N collection points, and calculate a corresponding correction distance focus _{zoom [N]} and Focus _zoom _[N-1], the calculated correction distance Focus arbitrary _zoom magnification corresponding to the zoom magnification value between the two adjacent points are collected:

Further, according to the reference zoom tracking curve, the theoretical focus acquiring module acquires the theoretical focus position Focus2 _zoom corresponding to the arbitrary zoom magnification value zoom between the adjacent collection points zoom _[N] and zoom _[N-1] , and then Calculating the actual focus position Focus1 _zoom corresponding to the zoom ratio value zoom by the second sampling unit:

Focus1 _zoom = focus _zoom +Focus2 _zoom

According to the above method, the second sampling unit can obtain the actual focus position value of the remaining points between any two adjacent collection points, and the specific number of samples can be determined according to actual conditions. Of course, the more the number of samples, the correction The more accurate the resulting zoom tracking curve is. Further, the correction module 14 performs correction on the existing reference zoom tracking curve according to the acquired coordinates of at least N (variable magnification value, actual focus position value).

In summary, the present application provides a correction device for a zoom tracking curve, which is pre-stored by the reference curve selection module 11 according to the current zoom direction and the preset rule corresponding to the zoom direction. The selected reference zoom tracking curve is selected in the theoretical zoom tracking curve, and N sampling points of different zoom magnification values are selected by the sampling module 12 on the theoretical reference zoom curve; and then the preset auto focus algorithm is adopted. The actual value obtaining module 13 obtains the actual focus position value when the focus estimation value reaches the maximum under the zoom magnification value corresponding to the collected points, and then completes the correction of the reference zoom tracking curve by the correction module 14. That is, the present application can select a reference zoom tracking curve by using a preset rule corresponding to the zoom direction for the current zoom direction, and obtain the actual focus position of the collection point by auto focus, and then obtain the actual of each lens itself by correction. The zoom tracking curve is used to ensure that the actual reference zoom tracking curve that has been corrected is synchronized in the subsequent zoom and auto focus, ensuring that the entire zoom process image can be focused clearly.

The various component embodiments of the present application can 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 some or all of the functionality of some or all of the components of the correction device for the zoom tracking curve in accordance with embodiments of the present application may be implemented in practice using a microprocessor or digital signal processor (DSP). . The application can 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 the present application 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. 5 illustrates a correction device that can implement a zoom tracking curve in accordance with the present application, such as a computer, mobile device, cell phone, PAD, portable multimedia player (PMP), TV, and the like. The electronic device conventionally includes a processor 510 and a computer program product or computer readable medium in the form of a memory 520. The memory 520 may be an electronic memory such as a flash memory, an EEPROM (Electrically Erasable Programmable Read Only Memory), an EPROM, a hard disk, or a ROM. Memory 520 has a memory space 530 for program code 531 for performing any of the method steps described above. For example, storage space 530 for program code may include various program code 531 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 computer program products are typically portable or fixed as described with reference to Figure 6. Storage unit. The storage unit may have a storage section, a storage space, and the like arranged similarly to the storage 520 in the electronic device of FIG. The program code can be compressed, for example, in an appropriate form. Typically, the storage unit comprises computer readable code 531 'is a code readable by a processor, such as 510, which when executed by an electronic device causes the electronic device to perform each of the methods described above step.

In the description provided herein, numerous specific details are set forth. However, it is understood that the embodiments of the present application 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.

It should be noted that the above-described embodiments are illustrative of the present application and are not intended to limit the scope of the application, 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" The application can 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 specification has been selected for the purpose of readability and teaching, and is not intended to be interpreted or limited. 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 present application is intended to be illustrative, and not restrictive, and the scope of the application is defined by the appended claims.

Claims

A method for correcting a zoom tracking curve, comprising:

According to the zoom direction and the corresponding preset rule, the reference zoom curve is selected from the pre-stored zoom curves with different focus distances to drive the zoom motor and the focus motor according to the reference zoom curve. Synchronous rotation

Selecting N collection points corresponding to different zoom magnification values on the reference zoom tracking curve;

Obtaining, according to a preset auto-focusing algorithm, an actual focus position value when the focus estimation value reaches a maximum value at a corresponding zoom magnification value of any one of the N collection points;

The correction of the reference zoom tracking curve is completed according to the obtained actual focus position values corresponding to the N collection points.
The method according to claim 1, wherein the selecting a reference zoom curve from the pre-stored at least two zoom tracking curves having different focus distances according to the zoom direction and its corresponding preset rule The steps include:

When the zoom direction is a small magnification to a large magnification, the focus motor is driven to obtain a corresponding focus position and a corresponding focus evaluation value of the current zoom magnification value in each zoom tracking curve, and the focus position with the largest focus evaluation value is determined. The zoom tracking curve is the reference zoom tracking curve.
The method according to claim 1, wherein the selecting a reference zoom curve from the pre-stored at least two zoom tracking curves having different focus distances according to the zoom direction and its corresponding preset rule The steps include:

Obtaining a current focus position of the focus motor when the zoom direction is a large magnification to a small magnification;

Obtaining a current zoom magnification value corresponding to a focus position in each zoom tracking curve, and determining a zoom tracking curve whose focus position is closest to the current focus position is the reference zoom tracking curve.
The method according to claim 1, wherein the step of selecting N collection points corresponding to different zoom magnification values on the reference zoom tracking curve comprises:

The number of collection points selected in different regions on the reference zoom tracking curve is proportional to the value of the zoom magnification corresponding to the center position point of the current region.
The method according to claim 4, wherein the reference zoom tracking curve is divided into different regions according to the magnitude of the zoom factor value.
The method of claim 1 further comprising the step of: obtaining the N The theoretical focus position value corresponding to any of the collection points on the reference zoom curve is calculated, and the correction distance between the theoretical focus position value and the actual focus position value is calculated.
The method of claim 6 wherein said corrected distance is a difference between said theoretical focus position value and an actual focus position value.
The method according to claim 6, further comprising the step of: calculating the adjacent two collection points on the reference zoom tracking curve by using a linear difference method and a corrected distance of any two adjacent acquisition points The actual focus position value between the remaining points.
The method according to claim 1, wherein the acquiring the actual focus when the focus estimation value reaches a maximum value at any of the N collection points based on the preset auto-focus algorithm The step of location value also includes:

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.
The method according to claim 9, wherein the preset focus estimation function is associated with a scene corresponding to the image data, wherein the scene is identified by a preset scene recognition algorithm.
A calibration device for a zoom tracking curve, comprising:

a reference curve selection module, configured to select a reference zoom curve from the pre-stored at least two zoom tracking curves with different focus distances according to the zoom direction and the corresponding preset rule, according to the reference zoom curve Driving the zoom motor and the focus motor to rotate synchronously;

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

An actual value obtaining module, configured to acquire, according to a preset auto-focusing algorithm, an actual focus position value when a focus estimation value of the N collection points reaches a maximum value at a corresponding zoom ratio value;

And a correction module, configured to complete the correction of the reference zoom tracking curve according to the obtained actual focus position values corresponding to the N collection points.
The apparatus according to claim 11, wherein the reference curve selection module further comprises a first selection unit,

The first selecting unit is configured to drive the focus motor to obtain a current zoom magnification value corresponding to a focus position in each zoom tracking curve when the zoom direction is a small magnification to a large magnification Corresponding focus evaluation value, the zoom tracking curve at which the focus position where the focus evaluation value is the largest is determined as the reference zoom tracking curve.
The device according to claim 11, wherein the reference curve selection module further comprises a second selection unit.

The second selecting unit is configured to acquire a current focus position of the focus motor when the zoom direction is a large magnification to a small magnification;

Obtaining a current zoom magnification value corresponding to a focus position in each zoom tracking curve, and determining a zoom tracking curve whose focus position is closest to the current focus position is the reference zoom tracking curve.
The apparatus according to claim 11, wherein the sampling module is further configured to use the number of collection points selected in different regions on the reference zoom tracking curve, and the zoom magnification value corresponding to the central position point of the current region is Just proportional.
The apparatus according to claim 14, wherein the sampling module is further configured to divide the reference zoom tracking curve into different regions according to the magnitude of the zoom factor value.
The device according to claim 11, further comprising a theoretical value acquisition module,

The theoretical value obtaining module is further configured to acquire a theoretical focus position value corresponding to any of the N collection points on the reference zoom tracking curve, and calculate between the theoretical focus position value and the actual focus position value. Correction distance.
The apparatus according to claim 16, wherein said correction distance is a difference between said theoretical focus position value and an actual focus position value.
The device according to claim 16, further comprising a second sampling unit,

The second sampling unit is configured to calculate a real focus of the remaining points between the adjacent two collection points on the reference zoom tracking curve by using a linear difference method and a correction distance of any two adjacent collection points Location value.
The device according to claim 11, wherein the actual value acquisition module is further configured to:

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.
The apparatus according to claim 19, wherein said predetermined focus estimate The value function is associated with a scene corresponding to the image data, wherein the scene is identified by a preset scene recognition algorithm.
A computer program comprising computer readable code causing the electronic device to perform correction of a zoom tracking curve according to any one of claims 1-10 when the computer readable code is run on an electronic device method.
A computer readable medium storing the computer program of claim 21.