CN103546692A - Method and system achieving integrated camera automatic focusing - Google Patents

Abstract

The invention provides a method and system for achieving integrated camera automatic focusing, and provides a zooming tracking method based on a relationship type, namely for a shot object at a fixed object distance, according to the initial zooming multiple, the value of an initial focusing position and a plurality of zooming tracking curves stored in advance, the mapping relation between the object distance interval and the focusing position is constructed, and the position to be focused is calculated in real time. Then, a gradient control function obtained by the combination of the statistical law of a lot of experimental data is utilized to achieve mobility control over a zooming motor and a focusing motor, the value of the position to be focused is improved and amended to a certain degree, the value of the position to be focused is closer to a real zooming tracking curve, and an automatic focusing effect is more accurate. Meanwhile, the zooming tracking curves are not needed to be stored in advance, all the zooming tracking curves corresponding to different object distances are not needed to be calculated point by point, an algorithm is simple, it is possible that the zooming speed meets a real-time property, and the focusing effect can meet the requirement for clearness in the whole process.

Description

A kind of self-focusing method and system of integrated camera that realize

Technical field

The invention belongs to Techniques of Automatic Focusing field, relate in particular to a kind of self-focusing method and system of integrated camera that realize, specifically a kind ofly based on zoom tracking curve, realize self-focusing method and system.

Background technology

As shown in Figure 1, integrated camera comprises image capture module, image processing module and imaging control module.Image capture module comprises focus-variable lens group 102, focusing lens group 103 and imageing sensor 104, in scene, object sends or the light 101 that reflects converges on the target surface of imageing sensor 104 by focus-variable lens group 102, focusing lens group 103, form clearly as, focus on.Imageing sensor is converted to the signal of telecommunication by imaging.Imaging control module 107, for control zoom motor 105 and focus on motor 106 with mobile focus-variable lens group 102 and focusing lens group 103 position in coupling, after guaranteeing to focus on, imaging is clear.Image processing module carries out a series of image processing operations to imaging and makes it can meet the requirement that human eye is watched.

At present, Techniques of Automatic Focusing based on Digital Image Processing has replaced the traditional auto focusing method based on range measurement principle gradually, traditional specific Digital Image Processing algorithm of the Techniques of Automatic Focusing utilization based on Digital Image Processing, obtain the evaluation of estimate (being generally the size of high fdrequency component) of image definition, and according to this evaluation of estimate, use the focusing motor 106 of certain algorithm and policy control camera lens to move to find fast maximum evaluation of estimate, obtain image clearly, this method need to expend a large amount of time for searching for maximum evaluation of estimate, greatly affected the speed focusing on, make this method can not be clear for realizing the whole process of zoom process.

In recent years, zoom is followed the tracks of a main part that has become automatic focus module in digital image processing field, so-called zoom is followed the tracks of and is referred to when object distance is fixedly time, imaging control module drive motors is the position in coupling with mobile focus-variable lens group 102 and focusing lens group 103, makes clear picture.The method that realizes zoom tracking mainly contains look-up table, linear interpolation method, self adaptation zoom tracing etc., and its core is all according to zoom tracking curve and controls corresponding focusing lens group 103 and 102 motions of focus-variable lens group.And look-up table needs to store in integrated camera in advance a large amount of zoom tracking curves through test, take more integrated camera internal memory, and when zoom motor moves from wide-angle side to angle far away end, traditional look-up table is difficult to choose suitable zoom tracking curve, causes focusing accurate not.And linear interpolation method is due to the non-linear error of bringing of zoom tracking curve, when the curvature of zoom tracking curve is larger, the error of simple linear interpolation method is also just larger, with and the impact of carrying out the noise introduced in Interpolation Process also cannot guarantee the accuracy of global focus.It is mainly to utilize automatic focus algorithm pointwise to obtain the aircraft pursuit course under different object distances that self adaptation zoom is followed the tracks of rule, the change calculations along with zoom multiple and object distance goes out the corresponding zoom tracking curve of every bit, although promoted self-focusing accuracy, but amount of calculation is excessive, whole arithmetic speed is poor, cause it to exist real-time poor, focus on and wait not continuously deficiency.To sum up, need badly a kind of can be in real time, efficiently, auto focusing method and system accurately.

Summary of the invention

For this reason, technical problem to be solved by this invention is cannot complete in real time, efficiently, accurately self-focusing problem in prior art, thereby proposes a kind of self-focusing method and system of integrated camera that realize.

For solving the problems of the technologies described above, the invention provides following technical scheme:

The self-focusing method of integrated camera, comprises the steps:

S1: also obtain object distance to be estimated interval in conjunction with at least two zoom tracking curves that store in advance according to initial zoom multiple and initial focus position;

S2: will described in object distance to be estimated interval divide equally, and set up according to this interval mapping relations with focal position of object distance;

S3: obtain actual object distance according to initial zoom multiple, initial focus position and described pre-stored zoom tracking curve interval;

S4: according to described mapping relations, obtain the corresponding focal position value of two endpoint values in described actual object distance interval, get its mean value as focal position value;

S5: by the variation relation between zoom multiple and focal position value, set up focus control function and make zoom motor and focus on that motor is controlled respectively focus-variable lens group and focusing lens group moves to relevant position.

In described step S2, also comprise the steps: further

Described in inciting somebody to action, object distance to be estimated interval is divided equally again, makes focal position to be estimated can meet above-mentioned mapping relations.

Focus control function described in described step S4 is for focusing on the gradient control function of the relation between motor removing step-length and zoom motor removing step-length further.

Described gradient control function is further

$n\left(i\right)=\left\{\begin{array}{cc}\mathrm{floor}(M/K)& i\≠K\\ M-(K-1)\left(\mathrm{floor}(M/K)\right)& i=K\end{array}\right.$

Wherein i represents the final step value of zoom motor, n (i) represents when focusing on the every Moving Unit step-length of motor, the moving step length of corresponding zoom motor, M represents that the zoom multiple step-length between final zoom multiple and initial zoom multiple is poor, K represents that the step-length of corresponding focal position is poor.

Also comprise the steps: further

S0: described many zoom tracking curves that store are in advance classified, be divided into the closely zoom tracking curve of zoom tracking curve, middle distance zoom tracking curve and remote zoom tracking curve three types according to different object distances;

Described step S1 also comprises:

When described, when estimating the corresponding object distance of focal position interval and be greater than the object distance value of zoom tracking curve closely, enter described step S2.

Further, used numerical value the last time of the integrated video camera memory of the numerical value of the initial zoom multiple described in described step S1 and initial focus.

Further, closely the object distance of zoom tracking curve is less than 2.5 meters.

Further, closely the object distance of zoom tracking curve is less than 2.0 meters.

The self-focusing system of integrated camera, comprising:

The interval acquisition module of object distance to be estimated: for also obtaining object distance to be estimated interval in conjunction with at least two zoom tracking curves that store in advance according to initial zoom multiple and initial focus position;

Mapping relations build module: for object distance to be estimated interval described in general, divide equally, and set up according to this mapping relations of object distance interval and focal position value;

The interval computing module of actual object distance: interval for obtaining actual object distance according to initial zoom multiple, initial focus positional value and described pre-stored zoom tracking curve;

Focal position acquisition module: for according to described mapping relations, obtain the corresponding focal position value of two endpoint values in described actual object distance interval, get its mean value as focal position value;

Focus control module: for carrying out focus control by the variation relation between zoom multiple and focal position value, set up focus control function and make zoom motor and focusing motor control respectively focus-variable lens group and focusing lens group moves to relevant position.

Described mapping relations build in module and also comprise further:

Equal sub-module: again divide equally for object distance to be estimated interval described in general, make focal position value to be estimated can meet above-mentioned mapping relations.

Focus control function described in described focus control module is for focusing on the gradient control function of the relation between motor removing step-length and zoom motor removing step-length further.

Described gradient control function is further

$n\left(i\right)=\left\{\begin{array}{cc}\mathrm{floor}(M/K)& i\≠K\\ M-(K-1)\left(\mathrm{floor}(M/K)\right)& i=K\end{array}\right.$

Wherein i represents the final step value of zoom motor, n (i) represents when focusing on the every Moving Unit step-length of motor, the moving step length of corresponding zoom motor, M represents that the zoom multiple step-length between final zoom multiple and initial zoom multiple is poor, K represents that the step-length of corresponding focal position is poor.

Also comprise further:

Curve classification module: for described many zoom tracking curves that store are in advance classified, be divided into the closely zoom tracking curve of zoom tracking curve, middle distance zoom tracking curve and remote zoom tracking curve three types according to different object distances;

The interval acquisition module of object distance described to be estimated also comprises:

Object distance judge module: for when described in when estimating the corresponding object distance of focal position interval and be greater than the object distance value of zoom tracking curve closely, enter described mapping relations and build module.

Used numerical value the last time that further, the integrated video camera of numerical value of the initial zoom multiple described in the interval acquisition module of object distance to be estimated and initial focus is remembered.

Further, closely the object distance of zoom tracking curve is less than 2.5 meters.

Further, closely the object distance of zoom tracking curve is less than 2.0 meters.

Technique scheme of the present invention has the following advantages compared to existing technology:

(1) a kind of self-focusing method and system of integrated camera that realize of the present invention, a kind of zoom tracking based on relationship type is provided, for the object of fixture distance, according to the numerical value of initial zoom multiple and initial focus position, and in many zoom tracking curves that store in advance, set up the mapping relations of object distance interval and focal position, and calculate in real time focal position value to be estimated, then applying focus control function has realized zoom motor and the mobile control that focuses on motor, make the zoom tracking curve that estimates comparatively accurate, focusing speed meets requirement of real time, focusing effect meets whole process requirement clearly.

(2) a kind of self-focusing method and system of integrated camera that realize of the present invention, under the fixing prerequisite of object distance, along with the variation of zoom multiple, in real time focal position is estimated, without a large amount of zoom tracking curve that prestores in advance, thereby just do not need to take the internal memory of too much integrated camera yet.Without pointwise, obtain the corresponding all zoom tracking curves under different object distances simultaneously, but under the prerequisite of certain object distance, obtain the corresponding zoom tracking curve of this object distance, algorithm is simple, there is no too huge amount of calculation, this has also promoted arithmetic speed to a certain extent, and allowing focusing speed meet real-time becomes possibility, also makes the continuity focusing on meet the instructions for use that user is more and more higher.

(3) a kind of self-focusing method and system of integrated camera that realize of the present invention, the focus control strategy of selecting is for utilizing gradient control function control zoom motor and focus on motor removing to relevant position, described gradient control function is according to under object distance arbitrarily, the statistics rule of the moving step length of focusing motor and zoom motor draws, revise to a certain extent and perfect focal position value to be estimated, make it more approach real zoom tracking curve, promoted further self-focusing accuracy.

Accompanying drawing explanation

For content of the present invention is more likely to be clearly understood, below according to a particular embodiment of the invention and by reference to the accompanying drawings, the present invention is further detailed explanation, wherein

Fig. 1 is the system construction drawing of integrated camera of the present invention;

Fig. 2 realizes the self-focusing method flow diagram of integrated camera described in a kind of embodiment;

Fig. 3 is many zoom tracking curves;

Fig. 4 is for obtaining the interval schematic diagram of object distance to be estimated;

Fig. 5 obtains focal position value schematic diagram to be estimated;

Fig. 6 realizes the self-focusing system construction drawing of integrated camera described in a kind of embodiment.

In figure, Reference numeral is expressed as: the light that in 101-scene, object sends or reflects, and 102-focus-variable lens group, 103-focusing lens group, 104-imageing sensor, 105-zoom motor, 106-focuses on motor, 107-imaging control module.

Embodiment

embodiment 1

The present embodiment provides a kind of self-focusing method of integrated camera that realizes, and as shown in Figure 2, comprises the steps:

S1: also obtain object distance to be estimated interval in conjunction with at least two zoom tracking curves that store in advance according to initial zoom multiple and initial focus position.

S2: will described in object distance to be estimated interval divide equally, and set up according to this interval mapping relations with focal position of object distance.

S3: obtain actual object distance according to initial zoom multiple, initial focus position and described pre-stored zoom tracking curve interval.

S4: according to described mapping relations, obtain the corresponding focal position value of two endpoint values in described actual object distance interval, get its mean value as focal position value.

S5: by the variation relation between zoom multiple and focal position value, set up focus control function and make zoom motor and focus on that motor is controlled respectively focus-variable lens group and focusing lens group moves to relevant position.

The prerequisite that the present embodiment is implemented is in integrated camera, to need to store in advance at least two zoom tracking curves, described zoom tracking curve as shown in Figure 3, wherein under the fixing prerequisite of object distance, between described zoom multiple and focal position, have corresponding relation, each zoom multiple correspondence unique focal position value.And initial zoom multiple has reacted focus-variable lens group and the focusing lens group residing position when initial condition in integrated camera with initial focus positional value, system can easily obtain.

Take Fig. 3 as example, and abscissa is zoom multiple, and ordinate is focal position, therefore by described initial zoom figure place and described initial focus position, can in this coordinate system, determine a coordinate points.If the described coordinate points of determining drops on in described many zoom tracking curves just, so now we can directly obtain the object distance of this point, after this automatic focus process needn't be carried out in the method for carrying out described in the present embodiment, and the numerical value that only need to record according to this zoom tracking curve makes zoom motor and focuses on that motor is controlled respectively focus-variable lens group and focusing lens group moves to relevant position.Even but this possibility occurring the in the situation that of a large amount of zoom tracking curve of storage is also little, generally we cannot find the object distance value that meets two value conditions in many zoom tracking curves simultaneously.Be more to have dropped between two zoom tracking curves, as shown in Figure 4, the abscissa that wherein A point is corresponding is initial zoom multiple, and ordinate is initial focus position, and now to drop on object distance be d to A point _middlezoom tracking curve and object distance be d _farzoom tracking curve between, therefore can obtain object distance to be estimated interval, be [d _middle, d _far].

As everyone knows, in shooting process, along with the variation of zoom multiple, focal position value also should change thereupon.And the variation of zoom multiple is because the artificial adjustment that user carries out integrated camera, we can obtain the concrete numerical value of zoom multiple accurately at any time, but current object distance value and the focal position value of clear picture cannot be obtained, this just needs us by known numerical value parameter, to calculate acquisition focal position value.By object distance the to be estimated interval obtaining is divided equally, and then can set up the interval mapping relations with focal position of object distance.Concrete grammar is as follows:

By object distance the to be estimated interval [d obtaining _middle, d _far] to be divided into width be D _z1n _z1individual minizone,

${\mathrm{<figure-callout\; id="1"\; label="D\; Z"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">D</figure-callout>}}_Z=\frac{d_{\mathrm{far}}-d_{\mathrm{middle}}}{n_{z1}}---\left(1\right)$

Simultaneously more careful for what make to divide equally, accuracy is higher, to n _z1setting value as follows:

$\mathrm{<figure-callout\; id="1"\; label="nz"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">nz</figure-callout>}1=\frac{\mathrm{\&Delta;<figure-callout\; id="1"\; label="z"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">z</figure-callout>}1*(\mathrm{\&Delta;<figure-callout\; id="1"\; label="z"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">z</figure-callout>}1+1)}{2}---\left(2\right)$

Wherein $\mathrm{\&Delta;<figure-callout\; id="1"\; label="z"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">z</figure-callout>}1=(F_{d_{\mathrm{middle}}}\left(z_{\mathrm{init}}\right)-F_{d_{\mathrm{far}}}\left(z_{\mathrm{init}}\right)+1)---\left(3\right)$

Fd herein _middle(z _init) for object distance be d _middletime initial zoom multiple corresponding focal position value, Fd _far(z _init) for object distance be d _fartime initial zoom multiple corresponding focal position value.After completing and dividing equally, we set up the mapping relations between the interval and focal position value of object distance, $[\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">d</figure-callout>}1,d2]\&LeftRightArrow;(F_{d_{\mathrm{middle}}}\left(z\right)-s),$

The zoom multiple of z herein for changing, the actual object distance interval of object distance interval [d1, d2] for obtaining.Here s=0,1,2..., Δ z1-1, now we can see s is got after different values is brought mapping relations into and can be obtained

extremely

, corresponding focal position value can be found in each the object distance interval in the interval of dividing equally, and so far we have completed the foundation of mapping relations.If by this relation known we go for the focal position value to be estimated that we need to try to achieve, need to obtain the actual value in its corresponding object distance interval, but not very wide in range [d _middle, d _far].We obtain d by formula below ₁and d ₂numerical value.

${\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">d</figure-callout>}}_1=d_{\mathrm{middle}}+\frac{s_m\&times;(s_m+1)}{2}\&times;D_{z1}---\left(4\right)$

d ₂＝d ₁+(s _m+1)×D _z1 （5）

S herein _mcan be obtained by formula below:

s _m＝F _dmiddle(z _init)-F ^afstart(z _init) （6）

F herein ^afstart(z _inint) be the corresponding focal position value of initial zoom multiple, the s of formula (6) _mcan obtain is a determined value, due to d _middleknown, D _z1for set point, therefore can obtain d ₁value, can draw d equally ₂value, has so far just obtained actual object distance interval.

According to described mapping relations, obtain the corresponding focal position value of two endpoint values in described actual object distance interval, get its mean value as focal position value.Finally by the variation relation between zoom multiple and focal position value, set up focus control function and make zoom motor and focusing motor control respectively focus-variable lens group and focusing lens group moves to relevant position, complete automatic focus.

A kind of self-focusing method of integrated camera that realizes described in the present embodiment, a kind of zoom tracking based on relationship type is provided, for the object of fixture distance, according to the numerical value of initial zoom multiple and initial focus position, and many zoom tracking curves that store in advance, set up the mapping relations of object distance interval and focal position, and calculate in real time focal position value to be estimated, then applying focus control function has realized zoom motor and the mobile control that focuses on motor, make the zoom tracking curve that estimates comparatively accurate, focusing speed meets requirement of real time, focusing effect meets whole process requirement clearly.

Described in the present embodiment, in step S2, also comprise the steps:

Described in inciting somebody to action, object distance to be estimated interval is divided equally again, makes focal position value to be estimated can meet above-mentioned mapping relations.The same by [d _middle, d _far] interval is divided into nz2 the minizone that width is Dz2, so just there is following formula:

$\mathrm{<figure-callout\; id="2"\; label="Dz"\; filenames="HDA0000407647550000021.png,HDA0000407647550000022.png"\; state="\{\{state\}\}">Dz</figure-callout>}2=\frac{d_{\mathrm{far}}-d_{\mathrm{middle}}}{\mathrm{nz}2}---\left(7\right)$

$\mathrm{\&Delta;<figure-callout\; id="2"\; label="z"\; filenames="HDA0000407647550000021.png,HDA0000407647550000022.png"\; state="\{\{state\}\}">z</figure-callout>}2=(F_{d_{\mathrm{middle}}}\left(z\right)-f_{d_{\mathrm{far}}}\left(z\right)+1)---\left(9\right)$

Through dividing equally, make focal position value to be estimated can meet mapping relations.According to acquired d ₁and d ₂numerical value, obtain 2 focal position values of locating.

Computational methods are followed mapping relations, as shown in Figure 5, and

${\hat{F}}_z\left(d_1\right)=F_{d_{\mathrm{middle}}}\left(z\right)-(s_1-1)---\left(10\right)$

${\hat{F}}_z\left(d_2\right)=F_{d_{\mathrm{middle}}}\left(z\right)-(s_2-1)---\left(11\right)$

And s ₁with s ₂can be determined by two inequality below:

$\frac{{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">s</figure-callout>}}_1\&times;(s_1-1)}{2}\&le;\frac{d_1-d_{\mathrm{<figure-callout\; id="2"\; label="middle\; D\; z"\; filenames="HDA0000407647550000021.png,HDA0000407647550000022.png"\; state="\{\{state\}\}">middle</figure-callout>}}}{D_z}\&le;\frac{s_1\&times;({\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">s</figure-callout>}}_1+1)}{2}---\left(12\right)$

$\frac{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HDA0000407647550000021.png,HDA0000407647550000022.png"\; state="\{\{state\}\}">s</figure-callout>}}_2\&times;(s_2-1)}{2}\&le;\frac{d_2-d_{\mathrm{<figure-callout\; id="2"\; label="middle\; D\; z"\; filenames="HDA0000407647550000021.png,HDA0000407647550000022.png"\; state="\{\{state\}\}">middle</figure-callout>}}}{D_z}\&le;\frac{s_2\&times;({\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HDA0000407647550000021.png,HDA0000407647550000022.png"\; state="\{\{state\}\}">s</figure-callout>}}_2+1)}{2}---\left(13\right)$

By formula 12, utilize the mean value method can be in the hope of unique s ₁numerical value, in like manner, can be in the hope of unique s by formula 13 ₂numerical value, then can be in the hope of formula 10 and the listed focal position value of 2 of formula 11.The focal position value now obtaining, comparatively accurate.Wherein the setting of the numerical value of Dz1 and Dz2 all obtains by lot of experimental data, can guarantee to a certain extent the accuracy of calculating.

The present embodiment, under the fixing prerequisite of object distance, estimates focal position in real time along with the variation of zoom multiple, without prestoring in advance a large amount of zoom tracking curves, thereby also just do not need to take the internal memory of too much integrated camera.Without pointwise, obtain the corresponding all zoom tracking curves under different object distances simultaneously, but under the prerequisite of certain object distance, obtain the corresponding zoom tracking curve of this object distance, algorithm is simple, there is no too huge amount of calculation, this has also promoted arithmetic speed to a certain extent, and allowing focusing speed meet real-time becomes possibility, also makes the continuity focusing on meet the instructions for use that user is more and more higher.

All there is the problem of a focus control in all focusing algorithm finally, according to the data characteristics of the focal position value under given fixture distance, for object distance arbitrarily, due to from wide-angle side to narrow angle end 3500 steps with the moving step length difference of interior any zoom motor be all correspondence focus on the more than 3 times of motor removing step-length difference, statistics rule based on such, the focus control function described in step S4 is for focusing on the gradient control function of the relation between motor removing step-length and zoom motor removing step-length described in the present embodiment.

Described gradient control function is

$n\left(i\right)=\left\{\begin{array}{cc}\mathrm{floor}(M/K)& i\&NotEqual;K\\ M-(K-1)\left(\mathrm{floor}(M/K)\right)& i=K\end{array}\right.---\left(14\right)$

Wherein i represents the final step value of zoom motor, n (i) represents when focusing on the every Moving Unit step-length of motor, the moving step length of corresponding zoom motor, M represents that the zoom multiple step-length between final zoom multiple and initial zoom multiple is poor, K represents that the step-length of corresponding focal position is poor.

For example, according to zoom tracking curve, suppose that zoom electric machine rotation scope is divided into 400 sections, the position that is represented current zoom motor by calculator 1-400, when zoom motor turns to (i+1) by i, zoom Electric Machine Control variable focus lens package is rotated Z towards imageing sensor direction _i+1-Z _istep-length.Otherwise when zoom motor turns to i by (i+1), zoom Electric Machine Control variable focus lens package is towards rotating Zi+1-Zi step-length away from imageing sensor direction.Also there is corresponding corresponding relation in same focusing motor and focus lens group, belongs to techniques well known, do not repeating herein.Formula 14 being done to one herein simply illustrates, according to implementing, gradient control function is known, when i changes to 130 by 60, corresponding M is 70, in like manner obtain K and be assumed to be 30, n (i) is 2 by gradient control function, and, whenever variable focus lens package moves two steps, focus lens group is moved and moved a step.

A kind of self-focusing method of integrated camera that realizes described in the present embodiment, the focus control strategy of selecting is for utilizing gradient control function control zoom motor and focus on motor removing to relevant position, described gradient control function is according to under object distance arbitrarily, the statistics rule of the moving step length of focusing motor and zoom motor draws, revise to a certain extent and perfect focal position value to be estimated, make it more approach real zoom tracking curve, promoted further self-focusing accuracy.

By zoom tracking curve, we can see in the situation that object distance is far away, and along with the expansion of zoom multiple, focal position value declines thereupon, and now we carry out automatic focus according to our method described above.But when object distance is nearer, the rule of zoom tracking curve is different from object distance when far away, and prior art can meet in-plant focusing demand, therefore the present embodiment also comprises the steps:

S0: described many zoom tracking curves that store are in advance classified, be divided into the closely zoom tracking curve of zoom tracking curve, middle distance zoom tracking curve and remote zoom tracking curve three types according to different object distances;

Described step S1 also comprises:

When described, when estimating the corresponding object distance of focal position interval and be greater than the object distance value of zoom tracking curve closely, enter described step S2.

Used numerical value the last time of the integrated video camera memory of numerical value of the initial zoom multiple described in described step S1 and initial focus.

The object distance of described closely zoom tracking curve is preferably and is less than 2.5 meters or be less than 2.0 meters.Being chosen as of this data obtains through lot of experimental data, herein as dividing, and can be so that closely and at a distance can obtain good focusing effect.But those skilled in the art should know, these data are just used for making embodiment fully to implement, but not restriction to the present embodiment, other variable datas are also within the protection range of the present embodiment.

By the division to different object distances, can, so that operate according to existing relatively ripe technology, just can easily carry out automatic focus closely time.When remote, by the method described in the present embodiment, carry out computing, the effect of acquisition is also comparatively obvious, can be because of the differentia influence focusing effect of object distance, so just can be in real time, omnidistance, realize automatic focus process efficiently, accurately.

embodiment 2

The present embodiment provides a kind of self-focusing system of integrated camera that realizes, and as shown in Figure 6, comprising:

The interval acquisition module of object distance to be estimated: for also obtaining object distance to be estimated interval in conjunction with at least two zoom tracking curves that store in advance according to initial zoom multiple and initial focus position.

Mapping relations build module: for object distance to be estimated interval described in general, divide equally, and set up according to this mapping relations of object distance interval and focal position.

The interval computing module of actual object distance: interval for obtaining actual object distance according to initial zoom multiple, initial focus position and described pre-stored zoom tracking curve.

Focal position acquisition module: for according to described mapping relations, obtain the corresponding focal position value of two endpoint values in described actual object distance interval, get its mean value as focal position value.

Focus control module: for by the variation relation between zoom multiple and focal position value, set up focus control function and make zoom motor and focusing motor control respectively focus-variable lens group and focusing lens group moves to relevant position.

The prerequisite that the present embodiment is implemented is in integrated camera, to need to store in advance at least two zoom tracking curves, described zoom tracking curve as shown in Figure 3, wherein under the fixing prerequisite of object distance, between described zoom multiple and focal position, have curve corresponding relation, each zoom multiple correspondence unique focal position value.And initial zoom multiple has reacted focus-variable lens group and the focusing lens group residing position when initial condition in integrated camera with initial focus positional value, system can easily obtain.

Take Fig. 3 as example, and abscissa is zoom multiple, and ordinate is focal position, therefore by described initial zoom figure place and described initial focus position, can in this coordinate system, determine a coordinate points.If the described coordinate points of determining drops on in described many zoom tracking curves just, so now we can directly obtain the object distance of this point, after this automatic focus process needn't be carried out in the method for carrying out described in the present embodiment, and the numerical value that only need to record according to this zoom tracking curve makes zoom motor and focuses on that motor is controlled respectively focus-variable lens group and focusing lens group moves to relevant position.Even but this possibility occurring the in the situation that of a large amount of zoom tracking curve of storage is also little, generally we cannot find the focal position value that meets two value conditions in many zoom tracking curves simultaneously.Be more to have dropped between two zoom tracking curves, as shown in Figure 4, the abscissa that wherein A point is corresponding is initial zoom multiple, and ordinate is initial focus position, and now to drop on object distance be d to A point _middlezoom tracking curve and object distance be d _farzoom tracking curve between, therefore can obtain object distance to be estimated interval, be [d _middle, d _far].

As everyone knows, in shooting process, along with the variation of zoom multiple, focal position value also should change thereupon.And the variation of zoom multiple is because the artificial adjustment that user carries out integrated camera, we can obtain the concrete numerical value of zoom multiple accurately at any time, but current object distance value and the focal position value of clear picture cannot be obtained, this just needs us by known numerical value parameter, to calculate acquisition focal position value.By object distance the to be estimated interval obtaining is divided equally, and then can set up the interval mapping relations with focal position of object distance.Concrete grammar is as follows:

By object distance the to be estimated interval [d obtaining _middle, d _far] to be divided into width be D _z1n _z1individual minizone,

${\mathrm{<figure-callout\; id="1"\; label="D\; Z"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">D</figure-callout>}}_Z=\frac{d_{\mathrm{far}}-d_{\mathrm{middle}}}{n_{z1}}---\left(1\right)$

Simultaneously more careful for what make to divide equally, accuracy is higher, to n _z1setting value as follows:

$\mathrm{<figure-callout\; id="1"\; label="nz"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">nz</figure-callout>}1=\frac{\mathrm{\&Delta;<figure-callout\; id="1"\; label="z"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">z</figure-callout>}1*(\mathrm{\&Delta;<figure-callout\; id="1"\; label="z"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">z</figure-callout>}1+1)}{2}---\left(2\right)$

Wherein $\mathrm{\&Delta;<figure-callout\; id="1"\; label="z"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">z</figure-callout>}1=(F_{d_{\mathrm{middle}}}\left(z_{\mathrm{init}}\right)-F_{d_{\mathrm{far}}}\left(z_{\mathrm{init}}\right)+1)---\left(3\right)$

Fd herein _middle(z _init) for object distance be d _middletime initial zoom multiple corresponding focal position value, Fd _far(z _init) for object distance be d _fartime initial zoom multiple corresponding focal position value.After completing and dividing equally, we set up the mapping relations between the interval and focal position value of object distance, $[\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">d</figure-callout>}1,d2]\&LeftRightArrow;(F_{d_{\mathrm{middle}}}\left(z\right)-s),$

The zoom multiple of z herein for changing, the actual object distance interval of object distance interval [d1, d2] for obtaining.Here s=0,1,2..., Δ z1-1, now we can see s is got after different values is brought mapping relations into and can be obtained extremely corresponding focal position value can be found in each the object distance interval in the interval of dividing equally, and so far we have completed the foundation of mapping relations.If go for by this relation is known the focal position value to be estimated that we need to try to achieve, need to obtain the actual value in its corresponding object distance interval, but not very wide in range [d _middle, d _far].We obtain d by formula below ₁and d ₂numerical value.

${\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">d</figure-callout>}}_1=d_{\mathrm{middle}}+\frac{s_m\&times;(s_m+1)}{2}\&times;D_{z1}---\left(4\right)$

d ₂＝d ₁+(s _m+1)×D _z1 （5）

S herein _mcan be obtained by formula below:

s _m＝F _dmiddle(z _init)-F ^afstart(z _init) （6）

F herein ^afstart(z _inint) be the corresponding focal position value of initial zoom multiple, the s of formula (6) _mcan obtain is a determined value, due to d _middleknown, D _z1for set point, therefore can obtain d ₁value, can draw d equally ₂value, has so far just obtained actual object distance interval.

According to described mapping relations, obtain the corresponding focal position value of two endpoint values in described actual object distance interval, get its mean value as focal position value.Finally adopt by the variation relation between zoom multiple and focal position value, set up focus control function and make zoom motor and focusing motor control respectively focus-variable lens group and focusing lens group moves to relevant position, complete automatic focus.

A kind of self-focusing system of integrated camera that realizes described in the present embodiment, a kind of zoom tracking based on relationship type is provided, for the object of fixture distance, according to the numerical value of initial zoom multiple and initial focus position, and in many zoom tracking curves that store in advance, set up the mapping relations of object distance interval and focal position, and calculate in real time focal position value to be estimated, then applying focus control function has realized zoom motor and the mobile control that focuses on motor, make the zoom tracking curve that estimates comparatively accurate, focusing speed meets requirement of real time, focusing effect meets whole process requirement clearly.

Described in the present embodiment, mapping relations build in module and also comprise:

Equal sub-module: again divide equally for object distance to be estimated interval described in general, make focal position value to be estimated can meet above-mentioned mapping relations.The same by [d _middle, d _far] interval is divided into nz2 the minizone that width is Dz2, so just there is following formula:

$\mathrm{<figure-callout\; id="2"\; label="Dz"\; filenames="HDA0000407647550000021.png,HDA0000407647550000022.png"\; state="\{\{state\}\}">Dz</figure-callout>}2=\frac{d_{\mathrm{far}}-d_{\mathrm{middle}}}{\mathrm{nz}2}---\left(7\right)$

$\mathrm{\&Delta;<figure-callout\; id="2"\; label="z"\; filenames="HDA0000407647550000021.png,HDA0000407647550000022.png"\; state="\{\{state\}\}">z</figure-callout>}2=(F_{d_{\mathrm{middle}}}\left(z\right)-f_{d_{\mathrm{far}}}\left(z\right)+1)---\left(9\right)$

Through dividing equally, make focal position value to be estimated can meet mapping relations.According to acquired d ₁and d ₂numerical value, obtain 2 focal position values of locating.

Computational methods are followed mapping relations, as shown in Figure 5, and

${\hat{F}}_z\left(d_1\right)=F_{d_{\mathrm{middle}}}\left(z\right)-(s_1-1)---\left(10\right)$

${\hat{F}}_z\left(d_2\right)=F_{d_{\mathrm{middle}}}\left(z\right)-(s_2-1)---\left(11\right)$

And s ₁with s ₂can be determined by two inequality below:

$\frac{{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">s</figure-callout>}}_1\&times;(s_1-1)}{2}\&le;\frac{d_1-d_{\mathrm{<figure-callout\; id="2"\; label="middle\; D\; z"\; filenames="HDA0000407647550000021.png,HDA0000407647550000022.png"\; state="\{\{state\}\}">middle</figure-callout>}}}{D_z}\&le;\frac{s_1\&times;({\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="HDA0000407647550000021.png"\; state="\{\{state\}\}">s</figure-callout>}}_1+1)}{2}---\left(12\right)$

$\frac{{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HDA0000407647550000021.png,HDA0000407647550000022.png"\; state="\{\{state\}\}">s</figure-callout>}}_2\&times;(s_2-1)}{2}\&le;\frac{d_2-d_{\mathrm{<figure-callout\; id="2"\; label="middle\; D\; z"\; filenames="HDA0000407647550000021.png,HDA0000407647550000022.png"\; state="\{\{state\}\}">middle</figure-callout>}}}{D_z}\&le;\frac{s_2\&times;({\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="HDA0000407647550000021.png,HDA0000407647550000022.png"\; state="\{\{state\}\}">s</figure-callout>}}_2+1)}{2}---\left(13\right)$

Can be in the hope of unique s by the formula 12 utilization methods of average ₁numerical value, in like manner, can be in the hope of unique s by formula 13 ₂numerical value, then can be in the hope of formula 10 and the listed focal position value of 2 of formula 11.The focal position value now obtaining, comparatively accurate.Wherein the setting of the numerical value of Dz1 and Dz2 all obtains by lot of experimental data, can guarantee to a certain extent the accuracy of calculating.

The present embodiment, under the fixing prerequisite of object distance, estimates focal position in real time along with the variation of zoom multiple, without prestoring in advance a large amount of zoom tracking curves, thereby also just do not need to take the internal memory of too much integrated camera.Without pointwise, obtain the corresponding all zoom tracking curves under different object distances simultaneously, but under the prerequisite of certain object distance, obtain the corresponding zoom tracking curve of this object distance, algorithm is simple, there is no too huge amount of calculation, this has also promoted arithmetic speed to a certain extent, and allowing focusing speed meet real-time becomes possibility, also makes the continuity focusing on meet the instructions for use that user is more and more higher.

All there is the problem of a focus control in all focusing algorithm finally, according to the data characteristics of the focal position value under given fixture distance, for object distance arbitrarily, due to from wide-angle side to narrow angle end 3500 steps with the moving step length difference of interior any zoom motor be all correspondence focus on the more than 3 times of motor removing step-length difference, statistics rule based on such, the focus control function described in focus control module is for focusing on the gradient control function of the relation between motor removing step-length and zoom motor removing step-length described in the present embodiment.

Described gradient control function is

$n\left(i\right)=\left\{\begin{array}{cc}\mathrm{floor}(M/K)& i\&NotEqual;K\\ M-(K-1)\left(\mathrm{floor}(M/K)\right)& i=K\end{array}\right.---\left(14\right)$

Wherein i represents the final step value of zoom motor, n (i) represents when focusing on the every Moving Unit step-length of motor, the moving step length of corresponding zoom motor, M represents that the zoom multiple step-length between final zoom multiple and initial zoom multiple is poor, K represents that the step-length of corresponding focal position is poor.

For example, according to zoom tracking curve, suppose that zoom electric machine rotation scope is divided into 400 sections, the position that is represented current zoom motor by calculator 1-400, when zoom motor turns to (i+1) by i, zoom Electric Machine Control variable focus lens package is rotated Z towards imageing sensor direction _i+1-Z _istep-length.Otherwise when zoom motor turns to i by (i+1), zoom Electric Machine Control variable focus lens package is towards rotating Zi+1-Zi step-length away from imageing sensor direction.Also there is corresponding corresponding relation in same focusing motor and focus lens group, belongs to techniques well known, do not repeating herein.Formula 14 being done to one herein simply illustrates, according to implementing, gradient control function is known, when i changes to 130 by 60, corresponding M is 70, in like manner obtain K and be assumed to be 30, n (i) is 2 by gradient control function, and, whenever variable focus lens package moves two steps, focus lens group is moved and moved a step.

A kind of self-focusing system of integrated camera that realizes described in the present embodiment, the focus control strategy of selecting is for utilizing gradient control function control zoom motor and focus on motor removing to relevant position, described gradient control function is according to under object distance arbitrarily, the statistics rule of the moving step length of focusing motor and zoom motor draws, revise to a certain extent and perfect focal position value to be estimated, make it more approach real zoom tracking curve, promoted further self-focusing accuracy.

By zoom tracking curve, we can see in the situation that object distance is far away, and along with the expansion of zoom multiple, focal position value declines thereupon, and now we carry out automatic focus according to our above-mentioned described method.But when object distance is nearer, the rule of zoom tracking curve is different from object distance when far away, and prior art can meet in-plant focusing demand, therefore the present embodiment also comprises:

Curve classification module: for described many zoom tracking curves that store are in advance classified, be divided into the closely zoom tracking curve of zoom tracking curve, middle distance zoom tracking curve and remote zoom tracking curve three types according to different object distances;

The interval acquisition module of object distance described to be estimated also comprises:

Object distance judge module: for when described in when estimating the corresponding object distance of focal position interval and be greater than the focal position value of zoom tracking curve closely, enter described mapping relations and build module.

Used numerical value the last time of the integrated video camera memory of numerical value of the initial zoom multiple described in the interval acquisition module of object distance described to be estimated and initial focus.

The object distance of described closely zoom tracking curve is preferably and is less than 2.5 meters or be less than 2.0 meters.Being chosen as of this data obtains through lot of experimental data, herein as dividing, and can be so that closely and at a distance can obtain good focusing effect.But those skilled in the art should know, these data are just used for making embodiment fully to implement, but not restriction to the present embodiment, other variable datas are also within the protection range of the present embodiment.

By the division to different object distances, can, so that operate according to existing relatively ripe technology, just can easily carry out automatic focus closely time.When remote, by the method described in the present embodiment, carry out computing, the effect of acquisition is also comparatively obvious, can be because of the differentia influence focusing effect of object distance, so just can be in real time, omnidistance, realize automatic focus process efficiently, accurately.

Those skilled in the art should understand, embodiments of the invention can be provided as method, system or computer program.Therefore, the present invention can adopt complete hardware implementation example, implement software example or in conjunction with the form of the embodiment of software and hardware aspect completely.And the present invention can adopt the form that wherein includes the upper computer program of implementing of computer-usable storage medium (including but not limited to magnetic disc store, CD-ROM, optical memory etc.) of computer usable program code one or more.

The present invention is with reference to describing according to flow chart and/or the block diagram of the method for the embodiment of the present invention, equipment (system) and computer program.Should understand can be in computer program instructions realization flow figure and/or block diagram each flow process and/or the flow process in square frame and flow chart and/or block diagram and/or the combination of square frame.Can provide these computer program instructions to the processor of all-purpose computer, special-purpose computer, Embedded Processor or other programmable data processing device to produce a machine, the instruction of carrying out by the processor of computer or other programmable data processing device is produced for realizing the device in the function of flow process of flow chart or a plurality of flow process and/or square frame of block diagram or a plurality of square frame appointments.

These computer program instructions also can be stored in energy vectoring computer or the computer-readable memory of other programmable data processing device with ad hoc fashion work, the instruction that makes to be stored in this computer-readable memory produces the manufacture that comprises command device, and this command device is realized the function of appointment in flow process of flow chart or a plurality of flow process and/or square frame of block diagram or a plurality of square frame.

These computer program instructions also can be loaded in computer or other programmable data processing device, make to carry out sequence of operations step to produce computer implemented processing on computer or other programmable devices, thereby the instruction of carrying out is provided for realizing the step of the function of appointment in flow process of flow chart or a plurality of flow process and/or square frame of block diagram or a plurality of square frame on computer or other programmable devices.

Although described the preferred embodiments of the present invention, once those skilled in the art obtain the basic creative concept of cicada, can make other change and modification to these embodiment.So claims are intended to all changes and the modification that are interpreted as comprising preferred embodiment and fall into the scope of the invention.

Claims (16)

1. realize the self-focusing method of integrated camera, it is characterized in that, comprise the steps:

S1: also obtain object distance to be estimated interval in conjunction with at least two zoom tracking curves that store in advance according to initial zoom multiple and initial focus position;

S2: will described in object distance to be estimated interval divide equally, and set up according to this interval mapping relations with focal position of object distance;

S3: obtain actual object distance according to initial zoom multiple, initial focus position and described pre-stored zoom tracking curve interval;

S4: according to described mapping relations, obtain the corresponding focal position value of two endpoint values in described actual object distance interval, get its mean value as focal position value;

S5: by the variation relation between zoom multiple and focal position value, set up focus control function and make zoom motor and focus on that motor is controlled respectively focus-variable lens group and focusing lens group moves to relevant position.

2. the self-focusing method of integrated camera that realizes according to claim 1, is characterized in that, in described step S2, also comprises the steps:

Described in inciting somebody to action, object distance to be estimated interval is divided equally again, makes focal position to be estimated can meet above-mentioned mapping relations.

3. the self-focusing method of integrated camera that realizes according to claim 1 and 2, is characterized in that, the focus control function described in described step S4 is for focusing on the gradient control function of the relation between motor removing step-length and zoom motor removing step-length.

4. the self-focusing method of integrated camera that realizes according to claim 3, is characterized in that, described gradient control function is

$n\left(i\right)=\left\{\begin{array}{cc}\mathrm{floor}(M/K)& i\&NotEqual;K\\ M-(K-1)\left(\mathrm{floor}(M/K)\right)& i=K\end{array}\right.$

Wherein i represents the final step value of zoom motor, n (i) represents when focusing on the every Moving Unit step-length of motor, the moving step length of corresponding zoom motor, M represents that the zoom multiple step-length between final zoom multiple and initial zoom multiple is poor, K represents that the step-length of corresponding focal position is poor.

5. according to the arbitrary described self-focusing method of integrated camera that realizes of claim 1-4, it is characterized in that, also comprise the steps:

S0: described many zoom tracking curves that store are in advance classified, be divided into the closely zoom tracking curve of zoom tracking curve, middle distance zoom tracking curve and remote zoom tracking curve three types according to different object distances;

Described step S1 also comprises:

When described, when estimating the corresponding object distance of focal position interval and be greater than the object distance value of zoom tracking curve closely, enter described step S2.

6. according to the arbitrary described self-focusing method of integrated camera that realizes of claim 1-5, it is characterized in that, used numerical value the last time of the integrated video camera memory of numerical value of the initial zoom multiple described in described step S1 and initial focus.

7. the self-focusing method of integrated camera that realizes according to claim 5, is characterized in that, the object distance of described closely zoom tracking curve is less than 2.5 meters.

8. the self-focusing method of integrated camera that realizes according to claim 5, is characterized in that, the object distance of described closely zoom tracking curve is less than 2.0 meters.

9. realize the self-focusing system of integrated camera, it is characterized in that, comprising:

The interval acquisition module of object distance to be estimated: for also obtaining object distance to be estimated interval in conjunction with at least two zoom tracking curves that store in advance according to initial zoom multiple and initial focus position;

Mapping relations build module: for object distance to be estimated interval described in general, divide equally, and set up according to this mapping relations of object distance interval and focal position value;

The interval computing module of actual object distance: interval for obtaining actual object distance according to initial zoom multiple, initial focus positional value and described pre-stored zoom tracking curve;

Focal position acquisition module: for according to described mapping relations, obtain the corresponding focal position value of two endpoint values in described actual object distance interval, get its mean value as focal position value;

Focus control module: for carrying out focus control by the variation relation between zoom multiple and focal position value, set up focus control function and make zoom motor and focusing motor control respectively focus-variable lens group and focusing lens group moves to relevant position.

10. the self-focusing system of integrated camera that realizes according to claim 9, is characterized in that, described mapping relations build in module and also comprise:

Equal sub-module: again divide equally for object distance to be estimated interval described in general, make focal position value to be estimated can meet above-mentioned mapping relations.

11. according to the self-focusing system of integrated camera that realizes described in claim 9 or 10, it is characterized in that, the focus control function described in described focus control module is for focusing on the gradient control function of the relation between motor removing step-length and zoom motor removing step-length.

The 12. self-focusing systems of integrated camera that realize according to claim 11, is characterized in that, described gradient control function is

$n\left(i\right)=\left\{\begin{array}{cc}\mathrm{floor}(M/K)& i\&NotEqual;K\\ M-(K-1)\left(\mathrm{floor}(M/K)\right)& i=K\end{array}\right.$

Wherein i represents the final step value of zoom motor, n (i) represents when focusing on the every Moving Unit step-length of motor, the moving step length of corresponding zoom motor, M represents that the zoom multiple step-length between final zoom multiple and initial zoom multiple is poor, K represents that the step-length of corresponding focal position is poor.

13. according to the arbitrary described self-focusing system of integrated camera that realizes of claim 9-12, it is characterized in that, also comprises:

Curve classification module: for described many zoom tracking curves that store are in advance classified, be divided into the closely zoom tracking curve of zoom tracking curve, middle distance zoom tracking curve and remote zoom tracking curve three types according to different object distances;

The interval acquisition module of object distance described to be estimated also comprises:

Object distance judge module: for when described in when estimating the corresponding object distance of focal position interval and be greater than the object distance value of zoom tracking curve closely, enter described mapping relations and build module.

14. according to the arbitrary described self-focusing system of integrated camera that realizes of claim 9-14, it is characterized in that, described in the initial zoom multiple described in the interval acquisition module of object distance to be estimated and the integrated video camera of numerical value of initial focus last time of remembering use numerical value.

The 15. self-focusing systems of integrated camera that realize according to claim 14, is characterized in that, the object distance of described closely zoom tracking curve is less than 2.5 meters.

The 16. self-focusing systems of integrated camera that realize according to claim 14, is characterized in that, the object distance of described closely zoom tracking curve is less than 2.0 meters.

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