CN104038740A - Method and device for shielding privacy region of PTZ (Pan/Tilt/Zoom) surveillance camera - Google Patents

Abstract

The invention is applicable for the field of cameras, and provides a method and a device for shielding a privacy region of a PTZ (Pan/Tilt/Zoom) surveillance camera. The method comprises the steps of: acquiring and displaying videos; demarcating a range size of the privacy region; calculating a two-dimensional physic coordinate of the central point of the privacy region in the current scene based on an efficient focal distance of the camera and an efficient imaging target surface size of an image sensor, and converting the two-dimensional physic coordinate into an absolute angular coordinate; when a running parameter of the camera changes, converting the absolute angular coordinate of the central point of the privacy region into a corresponding two-dimensional coordinate in a new scene; shielding the privacy region based on the two-dimensional coordinate of the central point of the privacy region and the demarcated range size of the privacy region. In the method and the device for shielding the privacy region of the surveillance camera, the absolute angular coordinate obtained through calculation is more accurate as the efficient focal distance of the camera and the efficient target surface imaging size of the image sensor can be obtained exactly; furthermore, the calculation amount is small, and the reaction is fast as calculation of the absolute angular coordinate of the central point of the privacy region is only needed.

Description

A kind of method and device that covers PTZ CCTV camera privacy area

Technical field

The invention belongs to camcorder technology end field, relate in particular to a kind of method and device of the PTZ of covering CCTV camera privacy area.

Background technology

PTZ is writing a Chinese character in simplified form of Pan/Tilt/Zoom in safety monitoring application, represents comprehensive (upper and lower, the left and right) movement of The Cloud Terrace and camera lens zoom, Zoom control.

In the time that video camera moves, may there is covering the privacy area (or feature region) in visual field, such as described privacy area can be swimming pool, cloakroom or dressing room etc.In the running of Pan/Tilt/Zoom camera, its selection and zoom feature, make the change of object along with video camera viewing area, looks and move through display device screen.Therefore carry out when video camera and distantly penetrate, when the operation of inclination angle, the object (one or more) of crested to move through screen, and in the time of zoom operation, object also correspondence zoom in or out.When inclination angle hour, all level is through screen the object of crested and privacy area, but under compared with high dip angle, object seems arc and passes screen, therefore well occluding objects of privacy area.

For head it off, application number is that 200880106462.4 patent discloses a kind of privacy zone algorithm for PTZ dome cameras, be intended to remember to be defined the privacy area in space, concrete, by 4 radiographic markers, four turnings of described 4 ray contact mark privacy areas and there is absolute pan angle, inclination angle.This privacy area is defined by the rectangle frame of known pixels point coordinates, and described pixel coordinate is converted to angular coordinate, and then, in the time that video camera moves and prepare to show new scene, privacy area is superimposed in the target that will cover.Carry out location and the privacy area demonstration to object by the absolute angular position of former privacy area being changed into pixel coordinate.

Above-mentioned patent adopts the angle of visual field to calculate absolute angular position, but under actual conditions, the angle of visual field be difficult for obtaining and easily produce larger error, in addition, above-mentioned patent need to be calculated the coordinate of each flex point of rectangle privacy area, and to carry out Coordinate Conversion for each flex point coordinate, computing more complicated, and also the privacy area that only limits to rectangle covers.

Summary of the invention

In view of the above problems, the object of the present invention is to provide a kind of method and device of the PTZ of covering CCTV camera privacy area, be intended to solve in existing Pan/Tilt/Zoom camera, object covers the technical problem of processing poor effect, calculation process complexity.

On the one hand, the method that described kind is covered PTZ CCTV camera privacy area comprises the steps:

Gather video and show, the picture wherein showing comprises the privacy area of needs shielding;

Demarcate privacy area range size;

Calculate the two-dimentional physical coordinates of privacy area central point under current scene according to effective imaging target surface size of video camera effective focal length and imageing sensor, and convert described two-dimentional physical coordinates to absolute angular position;

When after video camera operational factor variation, convert the absolute angular position of privacy area central point to two-dimensional coordinate corresponding under new scene, described operational factor comprises at least one in distant firing angle, inclination angle and the focal length of camera of The Cloud Terrace;

According to the privacy area range size of the two-dimensional coordinate of described privacy area central point and demarcation, privacy area is covered to processing.

On the other hand, the device that covers the comprehensive PTZ CCTV camera of The Cloud Terrace privacy area described in comprises:

Gather display unit, for gathering video and showing, the picture wherein showing comprises the privacy area of needs shielding;

Region setup unit, for demarcating privacy area range size;

Coordinate transformation unit, for calculate the two-dimentional physical coordinates of privacy area central point under current scene according to effective imaging target surface size of video camera effective focal length and imageing sensor, and converts described two-dimentional physical coordinates to absolute angular position;

Coordinate generation unit, after changing when video camera operational factor, two-dimensional coordinate corresponding to the absolute angular position of privacy area central point convert under new scene to, described operational factor at least comprises in distant firing angle, inclination angle and the focal length of camera of The Cloud Terrace;

Cover processing unit, for according to the privacy area range size of the two-dimensional coordinate of described privacy area central point and demarcation, privacy area is covered to processing.

The invention has the beneficial effects as follows: the present invention is by there being effective target surface imaging size of video camera effective focal length and camera image sensor to calculate the absolute angular position of privacy area central point, because effective target surface imaging size of video camera effect focal length and imageing sensor can Obtaining Accurate, make the absolute angular position that calculates more accurate, in addition, the present invention only need calculate the absolute angular position of privacy area central point, amount of calculation is little, be swift in response, go for the privacy area of any shape, such as rectangle, circle, ellipse etc.

Brief description of the drawings

Fig. 1 is the flow chart of the method for covering PTZ CCTV camera privacy area that provides of first embodiment of the invention;

Fig. 2 is a kind of particular flow sheet of step S103 in Fig. 1;

Fig. 3 is imageing sensor target surface schematic diagram;

Fig. 4 is imageing sensor target surface imaging schematic diagram;

Fig. 5 is the block diagram of the device that covers PTZ CCTV camera privacy area that provides of second embodiment of the invention;

Fig. 6 is the preferred structure block diagram of coordinate transformation unit in Fig. 5;

Fig. 7 is the preferred structure block diagram that covers processing unit in Fig. 5.

Embodiment

In order to make object of the present invention, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein, only in order to explain the present invention, is not intended to limit the present invention.

For technical solutions according to the invention are described, describe below by specific embodiment.

embodiment mono-:

Fig. 1 shows the flow process of the method for covering PTZ CCTV camera privacy area that the embodiment of the present invention provides, and only shows for convenience of explanation the part relevant to the embodiment of the present invention.

The method of what the present embodiment provided cover PTZ CCTV camera privacy area comprises the steps:

Step S101, collection video demonstration, the picture wherein showing comprises the privacy area of needs shielding.

Pan/Tilt/Zoom camera real-time image acquisition, on the display device of monitoring client, can demonstrate in real time the image frame of collection, in the present invention, in the picture showing, some object needs crested, the present embodiment is set privacy area with occluding objects by use, and described object may be one or more.The object covering for each needs needs to arrange corresponding privacy area.When monitoring client is in the time that operational factor changes, the corresponding privacy area position that changes, so that privacy area occluding objects all the time.

Step S102, demarcation privacy area range size.

This step does not limit the shape of privacy area, can be rectangle, circle, triangle, ellipse etc., is generally as the criterion can cover object.Generally, described privacy area is preferably symmetric figure, while being rectangle such as privacy area, described demarcation privacy area scope comprises the coordinate of the upper left corner of rectangle and two pixels in the lower right corner, in the time that privacy area is circle, described demarcation privacy area scope comprises diameter and the center of circle pixel coordinate of privacy area, and concrete privacy area scope of demarcating is relevant with the shape of privacy area, as long as can uniquely determine.

Step S103, calculate the two-dimentional physical coordinates of privacy area central point under current scene according to effective imaging target surface size of video camera effective focal length and imageing sensor, and convert described two-dimentional physical coordinates to absolute angular position.

This step, by the effective focal length of video camera and effective imaging target surface size of imageing sensor under current scene, is determined the two-dimentional physical coordinates of privacy area central point under current scene by geometrical relationship.Because effective imaging target surface size of effective focal length and imageing sensor can accurately obtain, therefore can accurately calculate the two-dimentional physical coordinates of privacy area central point under current scene.Concrete, as the concrete preferred implementation of one, as shown in Figure 2, above-mentioned steps S103 specifically comprises:

S201, determine effective imaging target surface size according to the model of camera image sensor and picture disply resolution.

A corresponding Pan/Tilt/Zoom camera, model that can reader internal image transducer, then according to picture disply resolution, can determine effective imaging target surface size.The imaging target surface ABCD of imageing sensor as shown in Figure 3, Z is the central point of demarcating privacy area, suppose that privacy area is rectangle, can obtain the coordinate of upper left corner E and the coordinate of lower right corner J of privacy area, suppose that target surface horizontal direction has M pixel, vertical direction has N pixel, A point coordinates is (0,0) so, and C point coordinates is (M, N), target surface central point O (x ₀, y ₀).

S202, the current effective focal length of obtaining imageing sensor and current distant firing angle and the inclination angle of camera pan-tilt.

Obtain current effective focal length and current distant firing angle and the inclination angle of camera pan-tilt of imageing sensor at current time, suppose that it is β that camera pan-tilt is worked as top rake, the current firing angle that shakes of camera pan-tilt is α.

S203, the effective imaging target surface size of basis and privacy area range size are calculated the two-dimentional physical coordinates of privacy area central point.

According to above-mentioned definition, can calculate the two-dimentional physical coordinates (x of privacy area central point Z under current scene _z, y _z).Such as privacy area is rectangle, and the range size of the privacy area of demarcating is upper left corner E (Ex, Ey) and in the rectangular area that limits, lower right corner J (Jx, Jy), can determine so the two-dimentional physical coordinates (x of privacy area central point Z _z, y _z)=((Ex+Jx)/2, (Ey+Jy)/2).

S204, according to described two-dimentional physical coordinates, effective focal length, the current distant firing angle of The Cloud Terrace, inclination angle and effectively imaging target surface size calculate the absolute angular position of privacy area central point.

Fig. 4 is target surface imaging schematic diagram, and in diagram, imaging target surface is S, and focus is K, and the central point of privacy area is Z.The absolute angular position of supposing described privacy area central point for (α z, z), wherein, α z is the absolute angle of the horizontal direction of privacy area central point to β, β z is the absolute angle of the vertical direction of privacy area central point; Be that α z is the line of privacy area central point and focus and the angle of X-axis, β z is the line of privacy area central point and focus and the angle of Y-axis, and the plane parallel that X-axis Y-axis forms is in target surface, and focus position is the focus of X-axis Y-axis, and Z axis is perpendicular to target surface.Can obtain according to geometrical relationship:

${\mathrm{\β}}_z={\sin }^{-1}(\frac{\sqrt{{(y_z-y_o)}^2+{f_o}^2}}{\sqrt{{(x_z-x_o)}^2+{(y_z-y_o)}^2+{f_0}^2}}\×\sin ({\tan }^{-1}\frac{y_z-y_o}{f_0}+\mathrm{\β}))$

${\mathrm{\α}}_z={\sin }^{-1}\left(\frac{(x_z-x_o)}{\cos {\mathrm{\β}}_z\×\sqrt{{(x_z-x_o)}^2+{(y_z-y_o)}^2+{f_o}^2}}\right)+\mathrm{\α}$

Wherein, y _z-y ₀for privacy area central point on imageing sensor imaging plane is to the distance in the vertical direction of target surface central point, the mm of unit;

X _z-x ₀for privacy area central point on imageing sensor imaging plane is to the distance in the horizontal direction of target surface central point, the mm of unit;

F ₀effective focal length corresponding to video camera during for demarcation privacy area scope, unit is mm;

β is that camera pan-tilt is worked as top rake;

α is the current firing angle that shakes of camera pan-tilt.

Step S104, when after video camera operational factor variation, convert the absolute angular position of privacy area central point to two-dimensional coordinate corresponding under new scene, described operational factor at least comprises in distant firing angle, inclination angle and the focal length of camera of The Cloud Terrace.

In service at Pan/Tilt/Zoom camera, the change of video camera operational factor, described operational factor at least comprises in distant firing angle, inclination angle and the focal length of camera of The Cloud Terrace, the distant firing angle, inclination angle or the effective focal length that are camera pan-tilt change, now, under new scene, convert the absolute angular position of privacy area central point to two-dimensional coordinate.Concrete, the two-dimensional coordinate (x, y) of privacy area central point under described new scene, wherein:

$x=\frac{f\×\tan \left({\sin }^{-1}(\sin ({\mathrm{\α}}_z-{\mathrm{\α}}_x)\×\cos {\mathrm{\β}}_z)\right)}{\cos ({\sin }^{-1}\left(\frac{\sin {\mathrm{\β}}_z}{\cos \left({\sin }^{-1}(\sin ({\mathrm{\α}}_z-{\mathrm{\α}}_x)\×\cos {\mathrm{\β}}_z)\right)}\right)-{\mathrm{\β}}_x)}+x_o$

$y=f\×\tan ({\sin }^{-1}\left(\frac{\sin {\mathrm{\β}}_z}{\cos \left({\sin }^{-1}\left(\sin ({\mathrm{\α}}_z-{\mathrm{\α}}_x)\cos {\mathrm{\β}}_z\right)\right)}\right)-{\mathrm{\β}}_x)+y_o$

Wherein, f is after video camera operational factor changes, the effective focal length of video camera;

α z is the absolute angle of the horizontal direction of privacy area central point;

β z is the absolute angle of the vertical direction of privacy area central point;

α x is after video camera operational factor changes, the real-time distant firing angle of The Cloud Terrace;

β x is after video camera operational factor changes, the real-time inclination angle of The Cloud Terrace;

X ₀for the horizontal coordinate value of imageing sensor target surface central point;

Y ₀for the vertical coordinate value of imageing sensor target surface central point.

Step S105, according to the privacy area range size of the two-dimensional coordinate of described privacy area central point and demarcation, privacy area is covered to processing.

Acquire after the two-dimensional coordinate of privacy area central point under new scene, change according to the privacy area scope of demarcating in advance and video camera effective focal length, can determine the concrete location of pixels of the privacy area under new scene, then privacy area process is covered to processing, such as mosaic processing or other processing modes.Such as described privacy area is rectangular area, in this step, first according to the two-dimensional coordinate of described privacy area central point and rectangle privacy area range size, determine the pixel coordinate of each angle point of rectangle privacy area, then the rectangle privacy area being made up of each angle point is covered to processing.

The present embodiment compared with prior art, it is more accurate that the absolute angular position of privacy area central point calculates, and, the present invention only need calculate the absolute angular position of privacy area central point, without the absolute angular position that calculates four angle points, amount of calculation is little, is swift in response, and goes for the privacy area of any shape.

embodiment bis-:

Fig. 5 shows the block diagram of the device that covers PTZ CCTV camera privacy area that the embodiment of the present invention provides, and only shows for convenience of explanation the part relevant to the embodiment of the present invention.

The device of what the present embodiment provided cover PTZ CCTV camera privacy area comprises:

Gather display unit 51, for gathering video and showing, the picture wherein showing comprises the privacy area of needs shielding;

Region setup unit 52, for demarcating privacy area range size;

Coordinate transformation unit 53, for calculate the two-dimentional physical coordinates of privacy area central point under current scene according to effective imaging target surface size of video camera effective focal length and imageing sensor, and converts described two-dimentional physical coordinates to absolute angular position;

Coordinate generation unit 54, after changing when video camera operational factor, two-dimensional coordinate corresponding to the absolute angular position of privacy area central point convert under new scene to, described operational factor at least comprises in distant firing angle, inclination angle and the focal length of camera of The Cloud Terrace;

Cover processing unit 55, for according to the privacy area range size of the two-dimensional coordinate of described privacy area central point and demarcation, privacy area is covered to processing.

Wherein, preferred, as shown in Figure 6, described coordinate transformation unit 53 comprises:

Target surface size acquisition module 531, for determining effective imaging target surface size according to the model of camera image sensor and picture disply resolution;

Data acquisition module 532, for obtaining current effective focal length and current distant firing angle and the inclination angle of camera pan-tilt of imageing sensor;

Coordinate computing module 533, for the two-dimentional physical coordinates of the effective imaging target surface size of basis and privacy area range size calculating privacy area central point;

Coordinate transferring 534, for calculating the absolute angular position of privacy area central point according to described two-dimentional physical coordinates, effective focal length, the current distant firing angle of The Cloud Terrace, inclination angle and effective imaging target surface size.

The absolute angular position of stating privacy area central point that described coordinate generation unit 53 obtains for (α z, z), wherein, α z is the absolute angle of the horizontal direction of privacy area central point to β, β z is the absolute angle of the vertical direction of privacy area central point;

${\mathrm{\β}}_z={\sin }^{-1}(\frac{\sqrt{{(y_z-y_o)}^2+{f_o}^2}}{\sqrt{{(x_z-x_o)}^2+{(y_z-y_o)}^2+{f_0}^2}}\×\sin ({\tan }^{-1}\frac{y_z-y_o}{f_0}+\mathrm{\β}))$

${\mathrm{\α}}_z={\sin }^{-1}\left(\frac{(x_z-x_o)}{\cos {\mathrm{\β}}_z\×\sqrt{{(x_z-x_o)}^2+{(y_z-y_o)}^2+{f_o}^2}}\right)+\mathrm{\α}$

Wherein, y _z-y ₀for privacy area central point on imageing sensor imaging plane is to the distance in the vertical direction of target surface central point, the mm of unit;

X _z-x ₀for privacy area central point on imageing sensor imaging plane is to the distance in the horizontal direction of target surface central point, the mm of unit;

F ₀effective focal length corresponding to video camera during for demarcation privacy area scope, unit is mm;

β is that camera pan-tilt is worked as top rake;

α is the current firing angle that shakes of camera pan-tilt.

Further preferred, suppose that described privacy area is rectangular area, as shown in Figure 7, described in cover processing unit 55 and comprise:

Pixel coordinate determination module 551, for according to the two-dimensional coordinate of described privacy area central point and rectangle privacy area range size, determines the pixel coordinate of each angle point of rectangle privacy area;

Cover processing module 552, for the rectangle privacy area being made up of each angle point is covered to processing.

Wherein, under new scene, the two-dimensional coordinate of privacy area central point is (x, y), wherein:

$x=\frac{f\×\tan \left({\sin }^{-1}(\sin ({\mathrm{\α}}_z-{\mathrm{\α}}_x)\×\cos {\mathrm{\β}}_z)\right)}{\cos ({\sin }^{-1}\left(\frac{\sin {\mathrm{\β}}_z}{\cos \left({\sin }^{-1}(\sin ({\mathrm{\α}}_z-{\mathrm{\α}}_x)\×\cos {\mathrm{\β}}_z)\right)}\right)-{\mathrm{\β}}_x)}+x_o$

$y=f\×\tan ({\sin }^{-1}\left(\frac{\sin {\mathrm{\β}}_z}{\cos \left({\sin }^{-1}\left(\sin ({\mathrm{\α}}_z-{\mathrm{\α}}_x)\cos {\mathrm{\β}}_z\right)\right)}\right)-{\mathrm{\β}}_x)+y_o$

Wherein, f is after video camera operational factor changes, the effective focal length of video camera;

α z is the absolute angle of the horizontal direction of privacy area central point;

β z is the absolute angle of the vertical direction of privacy area central point;

α x is after video camera operational factor changes, the real-time distant firing angle of The Cloud Terrace;

β x is after video camera operational factor changes, the real-time inclination angle of The Cloud Terrace;

X ₀for the horizontal coordinate value of imageing sensor target surface central point;

Y ₀for the vertical coordinate value of imageing sensor target surface central point.

One of ordinary skill in the art will appreciate that, the all or part of step realizing in above-described embodiment method is can carry out the hardware that instruction is relevant by program to complete, described program can be being stored in a computer read/write memory medium, described storage medium, as ROM/RAM, disk, CD etc.

The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, all any amendments of doing within the spirit and principles in the present invention, be equal to and replace and improvement etc., within all should being included in protection scope of the present invention.

Claims (10)

1. a method of covering the comprehensive PTZ CCTV camera of The Cloud Terrace privacy area, is characterized in that, described method comprises:

Gather video and show, the picture wherein showing comprises the privacy area of needs shielding;

Demarcate privacy area range size;

Calculate the two-dimentional physical coordinates of privacy area central point under current scene according to effective imaging target surface size of video camera effective focal length and imageing sensor, and convert described two-dimentional physical coordinates to absolute angular position;

When after video camera operational factor variation, convert the absolute angular position of privacy area central point to two-dimensional coordinate corresponding under new scene, described operational factor at least comprises in distant firing angle, inclination angle and the focal length of camera of The Cloud Terrace;

According to the privacy area range size of the two-dimensional coordinate of described privacy area central point and demarcation, privacy area is covered to processing.

2. method as claimed in claim 1, it is characterized in that, the described two-dimentional physical coordinates that calculates privacy area central point under current scene according to effective imaging target surface size of video camera effective focal length and imageing sensor, and convert described two-dimentional physical coordinates to absolute angular position step, specifically comprise:

Determine effective imaging target surface size according to the model of camera image sensor and picture disply resolution;

Obtain current effective focal length and current distant firing angle and the inclination angle of camera pan-tilt of imageing sensor;

According to the two-dimentional physical coordinates of effective imaging target surface size and privacy area range size calculating privacy area central point;

Calculate the absolute angular position of privacy area central point according to described two-dimentional physical coordinates, effective focal length, the current distant firing angle of The Cloud Terrace, inclination angle and effective imaging target surface size.

3. method as claimed in claim 2, is characterized in that, the absolute angular position of described privacy area central point is (α z, β z), wherein, α z is the absolute angle of the horizontal direction of privacy area central point, and β z is the absolute angle of the vertical direction of privacy area central point;

${\mathrm{\β}}_z={\sin }^{-1}(\frac{\sqrt{{(y_z-y_o)}^2+{f_o}^2}}{\sqrt{{(x_z-x_o)}^2+{(y_z-y_o)}^2+{f_0}^2}}\×\sin ({\tan }^{-1}\frac{y_z-y_o}{f_0}+\mathrm{\β}))$

${\mathrm{\α}}_z={\sin }^{-1}\left(\frac{(x_z-x_o)}{\cos {\mathrm{\β}}_z\×\sqrt{{(x_z-x_o)}^2+{(y_z-y_o)}^2+{f_o}^2}}\right)+\mathrm{\α}$

Wherein, y _z-y ₀for privacy area central point on imageing sensor imaging plane is to the distance in the vertical direction of target surface central point, the mm of unit;

X _z-x ₀for privacy area central point on imageing sensor imaging plane is to the distance in the horizontal direction of target surface central point, the mm of unit;

F ₀effective focal length corresponding to video camera during for demarcation privacy area scope, unit is mm;

β is that camera pan-tilt is worked as top rake;

α is the current firing angle that shakes of camera pan-tilt.

4. method as described in claim 1-3 any one, it is characterized in that, described privacy area is rectangular area, described according to the privacy area range size of the two-dimensional coordinate of described privacy area central point and demarcation, privacy area is covered to treatment step, specifically comprises:

According to the two-dimensional coordinate of described privacy area central point and rectangle privacy area range size, determine the pixel coordinate of each angle point of rectangle privacy area;

The rectangle privacy area being made up of each angle point is covered to processing.

5. method as claimed in claim 4, is characterized in that, under described new scene, the two-dimensional coordinate of privacy area central point is (x, y), wherein:

$x=\frac{f\×\tan \left({\sin }^{-1}(\sin ({\mathrm{\α}}_z-{\mathrm{\α}}_x)\×\cos {\mathrm{\β}}_z)\right)}{\cos ({\sin }^{-1}\left(\frac{\sin {\mathrm{\β}}_z}{\cos \left({\sin }^{-1}(\sin ({\mathrm{\α}}_z-{\mathrm{\α}}_x)\×\cos {\mathrm{\β}}_z)\right)}\right)-{\mathrm{\β}}_x)}+x_o$

$y=f\×\tan ({\sin }^{-1}\left(\frac{\sin {\mathrm{\β}}_z}{\cos \left({\sin }^{-1}\left(\sin ({\mathrm{\α}}_z-{\mathrm{\α}}_x)\cos {\mathrm{\β}}_z\right)\right)}\right)-{\mathrm{\β}}_x)+y_o$

Wherein, f is after video camera operational factor changes, the effective focal length of video camera;

α z is the absolute angle of the horizontal direction of privacy area central point;

β z is the absolute angle of the vertical direction of privacy area central point;

α x is after video camera operational factor changes, the real-time distant firing angle of The Cloud Terrace;

β x is after video camera operational factor changes, the real-time inclination angle of The Cloud Terrace;

X ₀for the horizontal coordinate value of imageing sensor target surface central point;

Y ₀for the vertical coordinate value of imageing sensor target surface central point.

6. cover a device for the comprehensive PTZ CCTV camera of The Cloud Terrace privacy area, its feature is, described device comprises:

Gather display unit, for gathering video and showing, the picture wherein showing comprises the privacy area of needs shielding;

Region setup unit, for demarcating privacy area range size;

Coordinate transformation unit, for calculate the two-dimentional physical coordinates of privacy area central point under current scene according to effective imaging target surface size of video camera effective focal length and imageing sensor, and converts described two-dimentional physical coordinates to absolute angular position;

Coordinate generation unit, after changing when video camera operational factor, two-dimensional coordinate corresponding to the absolute angular position of privacy area central point convert under new scene to, described operational factor at least comprises in distant firing angle, inclination angle and the focal length of camera of The Cloud Terrace;

Cover processing unit, for according to the privacy area range size of the two-dimensional coordinate of described privacy area central point and demarcation, privacy area is covered to processing.

7. install as claimed in claim 6, it is characterized in that, described coordinate transformation unit comprises:

Target surface size acquisition module, for determining effective imaging target surface size according to the model of camera image sensor and picture disply resolution;

Data acquisition module, for obtaining current effective focal length and current distant firing angle and the inclination angle of camera pan-tilt of imageing sensor;

Coordinate computing module, for the two-dimentional physical coordinates of the effective imaging target surface size of basis and privacy area range size calculating privacy area central point;

Coordinate transferring, for calculating the absolute angular position of privacy area central point according to described two-dimentional physical coordinates, effective focal length, the current distant firing angle of The Cloud Terrace, inclination angle and effective imaging target surface size.

8. install as claimed in claim 7, it is characterized in that, the absolute angular position of stating privacy area central point that described coordinate generation unit obtains is (α z, β z), wherein, α z is the absolute angle of the horizontal direction of privacy area central point, and β z is the absolute angle of the vertical direction of privacy area central point;

${\mathrm{\β}}_z={\sin }^{-1}(\frac{\sqrt{{(y_z-y_o)}^2+{f_o}^2}}{\sqrt{{(x_z-x_o)}^2+{(y_z-y_o)}^2+{f_0}^2}}\×\sin ({\tan }^{-1}\frac{y_z-y_o}{f_0}+\mathrm{\β}))$

${\mathrm{\α}}_z={\sin }^{-1}\left(\frac{(x_z-x_o)}{\cos {\mathrm{\β}}_z\×\sqrt{{(x_z-x_o)}^2+{(y_z-y_o)}^2+{f_o}^2}}\right)+\mathrm{\α}$

Wherein, y _z-y ₀for privacy area central point on imageing sensor imaging plane is to the distance in the vertical direction of target surface central point, the mm of unit;

X _z-x ₀for privacy area central point on imageing sensor imaging plane is to the distance in the horizontal direction of target surface central point, the mm of unit;

F ₀effective focal length corresponding to video camera during for demarcation privacy area scope, unit is mm;

β is that camera pan-tilt is worked as top rake;

α is the current firing angle that shakes of camera pan-tilt.

9. as described in claim 6-8 any one, install, it is characterized in that, described privacy area is rectangular area, described in cover processing unit and comprise:

Pixel coordinate determination module, for according to the two-dimensional coordinate of described privacy area central point and rectangle privacy area range size, determines the pixel coordinate of each angle point of rectangle privacy area;

Cover processing module, for the rectangle privacy area being made up of each angle point is covered to processing.

10. install as claimed in claim 9, it is characterized in that, under new scene, the two-dimensional coordinate of privacy area central point is (x, y), wherein:

$x=\frac{f\×\tan \left({\sin }^{-1}(\sin ({\mathrm{\α}}_z-{\mathrm{\α}}_x)\×\cos {\mathrm{\β}}_z)\right)}{\cos ({\sin }^{-1}\left(\frac{\sin {\mathrm{\β}}_z}{\cos \left({\sin }^{-1}(\sin ({\mathrm{\α}}_z-{\mathrm{\α}}_x)\×\cos {\mathrm{\β}}_z)\right)}\right)-{\mathrm{\β}}_x)}+x_o$

$y=f\×\tan ({\sin }^{-1}\left(\frac{\sin {\mathrm{\β}}_z}{\cos \left({\sin }^{-1}\left(\sin ({\mathrm{\α}}_z-{\mathrm{\α}}_x)\cos {\mathrm{\β}}_z\right)\right)}\right)-{\mathrm{\β}}_x)+y_o$

Wherein, f is after video camera operational factor changes, the effective focal length of video camera;

α z is the absolute angle of the horizontal direction of privacy area central point;

β z is the absolute angle of the vertical direction of privacy area central point;

α x is after video camera operational factor changes, the real-time distant firing angle of The Cloud Terrace;

β x is after video camera operational factor changes, the real-time inclination angle of The Cloud Terrace;

X ₀for the horizontal coordinate value of imageing sensor target surface central point;

Y ₀for the vertical coordinate value of imageing sensor target surface central point.