CN106231171B - A kind of quick focusing method for video camera - Google Patents
A kind of quick focusing method for video camera Download PDFInfo
- Publication number
- CN106231171B CN106231171B CN201511035222.8A CN201511035222A CN106231171B CN 106231171 B CN106231171 B CN 106231171B CN 201511035222 A CN201511035222 A CN 201511035222A CN 106231171 B CN106231171 B CN 106231171B
- Authority
- CN
- China
- Prior art keywords
- focal position
- clarity
- focusing
- value
- maximum value
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/60—Control of cameras or camera modules
- H04N23/67—Focus control based on electronic image sensor signals
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Automatic Focus Adjustment (AREA)
- Focusing (AREA)
Abstract
The present invention provides a kind of quick focusing methods for video camera, include the following steps: S1: changing focal position, it is recorded in focusing simultaneously, clarity maximum value and its place focal position, clarity minimum value and its place focal position, current definition values and its place focal position；S2: compare the difference of clarity maxima and minima；S3: compare the difference of clarity maximum value and current value；S4: focal position where comparing clarity maximum value judges whether among focusing where clear minimum value and present convergence location；S5: while when meeting S2, S3, S4, it can determine the clearest point of image at the clarity maximum value of focusing.Quick focusing method of the present invention improves focusing speed on the basis of guaranteeing focusing accuracy.
Description
Technical field
The invention belongs to technical field of video monitoring, more particularly, to a kind of quick focusing method for video camera.
Background technique
In video monitoring, how video camera can be realized according to monitoring emphasis adjustment monitoring position and camera lens zoom size
It quickly focuses and directly influences video effect and supervisory function bit.
Now widely used focus method is all based on hill-climbing algorithm, and the optimization done on its basis.Although mesh
Before the algorithm that is widely present all promoting focusing speed as far as possible, but hill-climbing algorithm the shortcomings that there are apparent poor anti jamming capabilities,
Especially under darker scene, noise can largely influence the Exact Travelling focused, therefore focusing speed and accuracy can not
It gets both.
Summary of the invention
In view of this, the present invention is directed to propose a kind of quick focusing method for video camera, accurate to focus in guarantee
Focusing speed is improved on the basis of property.
In order to achieve the above objectives, the technical scheme of the present invention is realized as follows:
A kind of quick focusing method for video camera, includes the following steps:
S1: changing focal position, while being recorded in focusing, clarity maximum value and its place focal position, clear
Clear degree minimum value and its place focal position, current definition values and its place focal position；
S2: comparing the difference of clarity maxima and minima, no into comparing in next step when meeting the threshold value of setting
Then continue to change focal position；
S3: comparing the difference of clarity maximum value and current value, no into comparing in next step when meeting the threshold value of setting
Then continue to change focal position；
S4: focal position where comparing clarity maximum value, judge whether to focus where clear minimum value with it is current
Among focal position, if meeting condition, into next step, otherwise continue to change focal position；
S5: while when meeting S2, S3, S4, can determine the clearest point of image at the clarity maximum value of focusing,
It is not required to be further continued for adjusting focal position.
Further, described image sharpness evaluation function is Brenner function.
Further, the clarity of image is analyzed, determines that the current clarity of described image includes: extraction image
In each pixel boundary information；The boundary information of each pixel of the correspondence of described image is subjected to summation operation；According to operation
As a result clarity maximum value, clarity minimum value and the current definition values of described image are determined.
Further, it after step S4, that is, determines and focuses at clearest point, add and subtract the range of a step-length in its vicinity
It is interior, fine search is carried out, focusing correctness is further increased.
Compared with the existing technology, a kind of quick focusing method for video camera of the present invention has the advantage that
Focus method of the present invention need to only save three quantity of states in focusing, without consuming more memories
Data are accessed, data statistics and calculation amount are reduced；Without covering gamut, meets condition i.e. and can determine peak value position,
Improve focusing speed；Only general trend is judged in focusing, is had ignored the variation between consecutive points, is eliminated noise and ghost peak
Interference, improve focusing success rate.
Detailed description of the invention
The attached drawing for constituting a part of the invention is used to provide further understanding of the present invention, schematic reality of the invention
It applies example and its explanation is used to explain the present invention, do not constitute improper limitations of the present invention.In the accompanying drawings:
Fig. 1 is focus method flow diagram described in the embodiment of the present invention.
Specific embodiment
It should be noted that in the absence of conflict, the feature in embodiment and embodiment in the present invention can phase
Mutually combination.
In the description of the present invention, it is to be understood that, term " center ", " longitudinal direction ", " transverse direction ", "upper", "lower",
The orientation or positional relationship of the instructions such as "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outside" is
It is based on the orientation or positional relationship shown in the drawings, is merely for convenience of description of the present invention and simplification of the description, rather than instruction or dark
Show that signified device or element must have a particular orientation, be constructed and operated in a specific orientation, therefore should not be understood as pair
Limitation of the invention.In addition, term " first ", " second " etc. are used for description purposes only, it is not understood to indicate or imply phase
To importance or implicitly indicate the quantity of indicated technical characteristic.The feature for defining " first ", " second " etc. as a result, can
To explicitly or implicitly include one or more of the features.In the description of the present invention, unless otherwise indicated, " multiple "
It is meant that two or more.
In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, term " installation ", " phase
Even ", " connection " shall be understood in a broad sense, for example, it may be being fixedly connected, may be a detachable connection, or be integrally connected；It can
To be mechanical connection, it is also possible to be electrically connected；It can be directly connected, can also can be indirectly connected through an intermediary
Connection inside two elements.For the ordinary skill in the art, above-mentioned term can be understood by concrete condition
Concrete meaning in the present invention.
The present invention will be described in detail below with reference to the accompanying drawings and embodiments.
As shown in Figure 1, the quick focusing method according to an embodiment of the present invention for monitor camera includes:
S1: at the beginning of focusing, first start to change focal position to a direction, while recording in focusing
The maximum value Vmax of clarity, the minimum value Vmin and clarity current value Vnow of clarity and corresponding focusing position
Set Pmax, Pmin, Pnow；
S2: in comparison procedure, the difference of clarity maximum value Vmax and clarity minimum value Vmin is calculated, Vmax- is worked as
Vmin is greater than given threshold Thresh1, represents the requirement for meeting real peak, enters step S3, otherwise return step S1 continues to change
Focal position；
S3: in comparison procedure, the difference of clarity maximum value Vmax and current definition values Vnow is calculated, Vmax- is worked as
Vnow is greater than given threshold Thresh2, represents across peak value, enters step S4, and otherwise return step S1 continues to change poly-
Burnt position；
S4: in comparison procedure, judge whether the focal position Pmax of clarity maximum value is in clarity minimum value institute
Among focal position Pmin and present convergence location Pnow, if meeting condition, indicate at left and right sides of peak value to gather to reach
Burnt clearest point just at peak value, otherwise indicates peak value side of only passing by, not can determine that peak value position, need reversely to change
Focal position, then return step S1 continues to change focal position；
As optimization, threshold value Thresh1 and threshold value Thresh2 can link with image gain, and gain is bigger, and threshold value is higher,
Gain is smaller, and threshold value is smaller, can improve focusing accuracy while excluding the interference of noise and ghost peak in this way, subtract simultaneously
Few focal time.
As optimization, when the condition for being unsatisfactory for being mentioned in step S2, with big step-length fast search, accelerate search speed.
As optimization, it can determine and focus at clearest point after step S4, add and subtract the range of a step-length in its vicinity
It is interior, fine search is carried out, focusing correctness is further increased.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all in essence of the invention
Within mind and principle, any modification, equivalent replacement, improvement and so on be should all be included in the protection scope of the present invention.
Claims (4)
1. a kind of quick focusing method for video camera, which comprises the steps of:
S1: at the beginning of focusing, first start to change focal position to a direction, while being recorded in focusing, clearly
Clear degree maximum value and its place focal position, clarity minimum value and its place focal position, current definition values and its place
Focal position；
S2: comparing the difference of clarity maxima and minima, when meet setting threshold value when, into comparing in next step, otherwise after
It is continuous to change focal position；
S3: comparing the difference of clarity maximum value and current value, when meet setting threshold value when, into comparing in next step, otherwise after
It is continuous to change focal position；
S4: focal position where comparing clarity maximum value judges whether focusing and present convergence where clear minimum value
Among position, if meeting condition, into next step, otherwise needs reversely to change focal position, then return to S1 and continue to change
Focal position；
S5: while when meeting S2, S3, S4, it can determine that the clearest point of image at the clarity maximum value of focusing, is not required to
It is further continued for adjusting focal position.
2. a kind of quick focusing method for video camera according to claim 1, it is characterised in that: image definition is commented
Valence function is Brenner function.
3. a kind of quick focusing method for video camera according to claim 1, it is characterised in that: to the clear of image
Degree is analyzed, and determines that the current clarity of described image includes: to extract the boundary information of each pixel in image；By the figure
The boundary information of each pixel of the correspondence of picture carries out summation operation；Determine that the clarity of described image is maximum according to operation result
Value, clarity minimum value and current definition values.
4. a kind of quick focusing method for video camera according to claim 1, it is characterised in that: after step S4,
It determines and focuses at clearest point, in the range of adding and subtracting a step-length in its vicinity, carry out fine search, further increase focusing
Correctness.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201511035222.8A CN106231171B (en) | 2015-12-31 | 2015-12-31 | A kind of quick focusing method for video camera |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201511035222.8A CN106231171B (en) | 2015-12-31 | 2015-12-31 | A kind of quick focusing method for video camera |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106231171A CN106231171A (en) | 2016-12-14 |
| CN106231171B true CN106231171B (en) | 2019-08-20 |
Family
ID=57528734
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201511035222.8A Active CN106231171B (en) | 2015-12-31 | 2015-12-31 | A kind of quick focusing method for video camera |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106231171B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106791432A (en) * | 2017-01-18 | 2017-05-31 | 深圳竹信科技有限公司 | A kind of focal length determines method and device |
| CN111711759B (en) * | 2020-06-29 | 2022-02-01 | 重庆紫光华山智安科技有限公司 | Focusing method, device, storage medium and electronic equipment |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0421243A2 (en) * | 1989-09-29 | 1991-04-10 | Sanyo Electric Co., Ltd. | Automatic focusing camera |
| CN1065341A (en) * | 1991-02-19 | 1992-10-14 | 利诺泰普-赫尔有限公司 | The focus adjustment method of optical image system and device |
| CN101071251A (en) * | 2006-05-11 | 2007-11-14 | 致伸科技股份有限公司 | Method for estimating automatic focusing least effective sampling points |
| CN101494737A (en) * | 2009-03-09 | 2009-07-29 | 杭州海康威视数字技术股份有限公司 | Integrated camera device and self-adapting automatic focus method |
| CN102053339A (en) * | 2010-11-23 | 2011-05-11 | 天津市亚安科技电子有限公司 | Automatic focusing method |
| CN102520503A (en) * | 2011-12-27 | 2012-06-27 | 杭州恒胜电子科技有限公司 | Method for quickly focusing high-definition image acquisition equipment |
| CN103513395A (en) * | 2012-06-15 | 2014-01-15 | 中兴通讯股份有限公司 | Passive auto-focusing method and device |
-
2015
- 2015-12-31 CN CN201511035222.8A patent/CN106231171B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0421243A2 (en) * | 1989-09-29 | 1991-04-10 | Sanyo Electric Co., Ltd. | Automatic focusing camera |
| CN1065341A (en) * | 1991-02-19 | 1992-10-14 | 利诺泰普-赫尔有限公司 | The focus adjustment method of optical image system and device |
| CN101071251A (en) * | 2006-05-11 | 2007-11-14 | 致伸科技股份有限公司 | Method for estimating automatic focusing least effective sampling points |
| CN101494737A (en) * | 2009-03-09 | 2009-07-29 | 杭州海康威视数字技术股份有限公司 | Integrated camera device and self-adapting automatic focus method |
| CN102053339A (en) * | 2010-11-23 | 2011-05-11 | 天津市亚安科技电子有限公司 | Automatic focusing method |
| CN102520503A (en) * | 2011-12-27 | 2012-06-27 | 杭州恒胜电子科技有限公司 | Method for quickly focusing high-definition image acquisition equipment |
| CN103513395A (en) * | 2012-06-15 | 2014-01-15 | 中兴通讯股份有限公司 | Passive auto-focusing method and device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106231171A (en) | 2016-12-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103464869B (en) | The rotating the arc narrow gap MAG welding line deviation recognition device of view-based access control model sensing and method | |
| US11343432B2 (en) | Imaging apparatus | |
| CN102843513B (en) | The camera apparatus and method of target are recognized by using camera | |
| US8164682B2 (en) | Dithered focus evaluation | |
| US8970672B2 (en) | Three-dimensional image processing | |
| CN101272511B (en) | Method and device for acquiring image depth information and image pixel information | |
| EP2613518B1 (en) | Video signal processing apparatus | |
| CN105391945B (en) | Camera autofocus control method and device | |
| US10395348B2 (en) | Image pickup apparatus, image processing apparatus, and control method of image pickup apparatus | |
| KR102228456B1 (en) | Image pickup apparatus and image pickup method of generating image having depth information | |
| CN104070264B (en) | The narrow gap MAG of rotating the arc becoming groove width welds self adaptation pendulous device and method | |
| CN103248812A (en) | Image signal processing apparatus and image signal processing method | |
| CN103095983A (en) | Image signal processing device | |
| CN106231171B (en) | A kind of quick focusing method for video camera | |
| CN106506946B (en) | A kind of camera automatic focusing method and video camera | |
| CN105611158A (en) | Automatic focus following method and device and user equipment | |
| CN106973199B (en) | Multi-aperture camera system for improving depth accuracy by using focusing distance scanning | |
| CN106772925A (en) | A kind of passive camera automatic focusing method based on inner product energy | |
| CN103529544A (en) | Nano membrane thickness measuring instrument capable of automatically positioning and focusing | |
| CN110749974B (en) | Automatic focusing method of full-glass-slide imaging scanner and image acquisition method thereof | |
| KR102477757B1 (en) | Automatic focus system and method | |
| JP2014215476A (en) | Imaging apparatus and method for controlling the same | |
| CN105022138B (en) | Use the autofocus system and its method of more camera lenses | |
| KR20070040547A (en) | Method and apparatus for auto-focusing for camera | |
| KR102422125B1 (en) | Auto focusing method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |