CN103024344A

CN103024344A - Automatic PTZ (Pan/Tilt/Zoom) target tracking method based on particle filter

Info

Publication number: CN103024344A
Application number: CN2011102824962A
Authority: CN
Inventors: 赵刚; 张少文; 冯琰一
Original assignee: PCI Suntek Technology Co Ltd
Current assignee: PCI Suntek Technology Co Ltd
Priority date: 2011-09-20
Filing date: 2011-09-20
Publication date: 2013-04-03

Abstract

The invention discloses an automatic PTZ (Pan/Tilt/Zoom) target tracking method based on particle filter. The automatic PTZ target tracking method comprises the steps of detection of a moving target, target tracking and pan-and-tilt control. The method can allow a camera to lock the moving target automatically and implement automatic tracking of vision guidance, thereby overcoming the defect that a fixed camera has a narrow monitoring visual field. At first, the moving target is selected by a manual frame in a pre-set position or the moving target is automatically detected by a vision consistency algorithm; secondly, a target position is matched and tracked by the classic particle filter; and finally, a control order is sent according to the position and the size of the target, so that the position and the focal distance of the camera can be adjusted. When a tracking process fails, the camera automatically skips back to the pre-set position, and the detection of next turn can be carried out. The automatic PTZ target tracking method provided by the invention is reasonable in design, so that the automatic tracking function of the camera to the target can be realized, and the target is located in the middle of a lens all along. Therefore, the automatic PTZ target tracking method brings convenience to monitoring personnel.

Description

A kind of method of the PTZ automatically track target based on particle filter

Technical field

The present invention relates to computer vision field, particularly relate to a kind of method of the PTZ automatically track target based on particle filter.

Background technology

It is high that Pan/Tilt/Zoom camera has the fast precision of speed, and the advantage that monitoring range is large is one of monitoring frontend that the most generally uses in the monitoring field now.The automatic Tracking monitoring system of intelligence PTZ has the target analysis function, and is furnished with high-resolution camera, large multiplying power Zoom optic lens and high rotating speed The Cloud Terrace, and automatic capturing is to suspicious object fast and accurately.By presetting bit is set, the automatic Tracking monitoring system of intelligent PTZ can be realized the functions such as presetting bit scanning, automatic cruising.Therefore and unrealized real from motion tracking but this scanning is just blindly cruised, and fails the state of real-time target acquisition.Therefore need to propose the automatic tracking control technology of a kind of The Cloud Terrace, when The Cloud Terrace possesses the Automatic Target Tracking function, can control according to the actual motion information of target the motion of The Cloud Terrace, for the monitor staff provides more valuable monitor message.

Automatic tracking system based on PTZ mainly is divided into the two large divisions: the one, obtain target information according to video image, i.e. and target detection, another part mates target exactly, i.e. target following, and utilize trace information control video camera to rotate.At present, although many have the target detection of a lot of maturations and an algorithm of tracking, can be directly used in the ball machine of motion seldom.Because the rotation of camera, traditional background modeling method can not be used, and can not use based on the motion target tracking of testing result.Another major issue in the system is exactly the control of PTZ, there is difference in different servo-control systems to response speed and the accuracy of control command, in case reaching demand to the response of control command, control appliance just may not cause target in image, to be lost, image analysis algorithm so also must cause the failure of following the tracks of just with ineffective.Thereby closely link to each other with target detection, target following, PTZ control based on the performance of the automatic tracking system of PTZ.

Summary of the invention

Technical problem to be solved by this invention is the method that proposes a kind of PTZ automatically track target based on particle filter, automatically locks moving target and carries out visually oriented from motion tracking to realize video camera.

For achieving the above object, the present invention carries out manual frame in presetting bit first and selects moving target or utilize the vision consistency algorithm to carry out the automatic detection of moving target, the coupling of utilizing classical particle filtering to carry out the target location is followed the tracks of, according to position and the size transmission control command of target position and the focal length of video camera are adjusted at last, after following the tracks of unsuccessfully, automatically jump back to presetting bit, carry out the detection of next round.

Described particle filter is used for: seeks one group of random sample of propagating at state space probability density function is similar to, replace integral operation with sample average, thus the process of the state of acquisition minimum variance estimate.In the method, be used for the pursuit movement target.

The present invention also provides a kind of strategy of PTZ control, comprising: according to the tracing positional of target, calculate target from the distance of image center, if distance is then sent out the order that PTZ moves and is offset greater than the threshold value of setting; Account for the ratio of entire image when the size of target less than the threshold value of setting, then send the focus controlling order.All orders all are only to allow cam movement a bit of, and what namely realize is intermittent control.

Description of drawings

In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art, the below will do simple the introduction to the accompanying drawing of required use in embodiment or the description of the Prior Art, apparently, accompanying drawing in the following describes only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.

Fig. 1 is PTZ automatically track target structural representation in the embodiment of the invention one;

Fig. 2 is based on the particle filter tracking schematic flow sheet in the embodiment of the invention one;

Fig. 3 is The Cloud Terrace control flow schematic diagram in the embodiment of the invention one.

Embodiment

For above-mentioned purpose of the present invention, feature and advantage can be become apparent more, the present invention is further detailed explanation below in conjunction with the drawings and specific embodiments.Obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not making the every other embodiment that obtains under the creative work prerequisite.

Embodiment one, referring to Fig. 1, and Fig. 2, Fig. 3.

The course of work of said system specifically may further comprise the steps referring to Fig. 1:

Step 1, choose target to be tracked, can adopt manual mode, also can adopt automatic mode.

Step 2, utilization are followed the tracks of moving target based on the method for classical particle filtering, obtain the position of moving target.

The distance of step 3, judgement moving target and image center is controlled The Cloud Terrace.When target disappears or follows the tracks of unsuccessfully, jump to preset point, carry out detection next time.

Described tracking based on classical particle filtering specifically may further comprise the steps:

Step 1, initialization: get k=0, press p (x ₀) N sample point of extraction

I=1 ..., N

Step 5, resample: according to normalization weights separately

Size copy/give up sample

Obtain N approximate the obedience

The sample that distributes Order

Step 6, Output rusults: the output of algorithm is the particle collection Can approximate representation with it

Step 7, K=K+1 repeated for 2 steps to 6 steps.

The above only is the specific embodiment of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims

1. the method based on the PTZ automatically track target of particle filter is characterized in that, may further comprise the steps:

The first step: according to the needs of monitoring occasion, choose suitable presetting bit, manually frame selects target to be tracked in presetting bit, or utilizes based on the conforming moving object detection algorithm of vision, automatically detects moving target;

Second step: the coupling of utilizing classical particle filter method to carry out moving target position is followed the tracks of;

The 3rd step: position and size to target are analyzed, if the position of target exceeds the zone of setting, then send the order of camera motion; If target sizes is less than the threshold value of setting, the order of then sending adjusting focal length;

The 4th step: if target exceeds the catching range of video camera or follows the tracks of unsuccessfully, then jump to presetting bit, and return the first step, carry out next time tracking otherwise return second step.

2. the method for a kind of PTZ automatically track target based on particle filter according to claim 1, it is characterized in that, the described manual frame of the first step selects moving target to belong to manual mode, utilization belongs to automatic mode based on the conforming moving object detection algorithm of vision, when detecting a plurality of moving target, select the conduct target to be tracked of area maximum.

3. the method for a kind of PTZ automatically track target based on particle filter according to claim 1, it is characterized in that, the described classical particle filtering of second step is a kind ofly to utilize a kind of method of rewards and punishments mechanism estimated state value based on the dynamical system forward model, can be used for non linear system.

4. the method for a kind of PTZ automatically track target based on particle filter according to claim 1, it is characterized in that, the 3rd described camera translation of step and deflection control command, be to be determined by the distance that put to the optical center position of target, the focus controlling order is that the ratio that the size by target accounts for entire image determines.

5. the method for a kind of PTZ automatically track target based on particle filter according to claim 1, it is characterized in that, the 4th step is described, if target exceeds the catching range of video camera or follows the tracks of unsuccessfully, then jumping to presetting bit, is to be in the state of cisco unity malfunction for the failure that prevents from following the tracks of causes video camera.