CN106384367A - Method for automatically stabilizing view angle of panoramic camera - Google Patents

Abstract

The invention provides a method for automatically stabilizing a shooting view angle of a panoramic camera. Based on data of an inclination measurement sensor, a global transformation mapping algorithm is performed on a shot panoramic image, and the panoramic image is automatically corrected into an image with a vertical erected view angle in a software mode, so that panoramic video or images with a good viewing effect can still be provided under the condition that the shooting posture is instable.

Description

A kind of method at the automatic stabilisation visual angle of panorama camera

Technical field

The present invention relates to photography and vedio recording field, the method at the automatic stabilisation visual angle of more particularly, to a kind of panorama camera.

Background technology

Panorama camera, due to its good experience and portability when participating in the cintest, has been increasingly being used for net cast and picture Share occasion.In common hand-held or follow shot scene, attitude when camera shoots cannot keep stable.Although due to complete The ultraphotic angle feature of scape camera, can't lead to watch the disappearance of content, but the variation at visual angle still can play end in panorama Lead to the decline of Consumer's Experience.

Content of the invention

In order to solve problem in prior art, the invention provides a kind of method at the automatic stabilisation visual angle of panorama camera, Image unit integral inclined to a certain degree when, its projection sphere is actual to be there is certain rotation with respect to scene in kind or inclines Tiltedly, two deflection angle data (θ, φ) are given, under spheric coordinate systems, wherein φ is the angle of OP and plane XOZ, and θ exists for OP Equatoriat plane projection and the angle of OX；On sphere, the coordinate of point P for (θ, φ) when deflection angle θ ≠ 0 and φ ≠ 0, make by the equatoriat plane Angle is the rotation of φ, and this spin matrix can be written as

Wherein vectorIt is represented byThen cross product

Make quaternary number

Quaternary number form formula can be converted into using triangular equation

Wherein

Therefore have

$R\left(q\right)=\left[\begin{array}{ccc}1-2(y^2+z^2)& 2(xy-zw)& 2(xz+yw)\\ 2(xy+zw)& 1-2(x^2+z^2)& 2(yz-xw)\\ 2(xz-yw)& 2(yz+xw)& 1-2(x^2+y^2)\end{array}\right]$

CauseHave

Then

$R\left(q\right)=\left[\begin{array}{ccc}1-2z^2& -2zw& 2xz\\ 2zw& 1-2(x^2+z^2)& -2xw\\ 2xz& 2xw& 1-2x^2\end{array}\right].$

The invention has the beneficial effects as follows：

Based on the data of inclination measuring sensor, carry out global change's mapping algorithm to shooting the panoramic picture obtaining, By software mode, panoramic picture is corrected as automatically the image at vertically upright visual angle, thus in the situation shooting unsteady attitude Under be still provided that the panoramic video/image of good viewing effect.

The panorama test image shooting for certain Zhang Feizheng standing position state is corrected.Camera shooting effect in an inclined state As Fig. 2：

According to tilt parameters, the such as Fig. 3 of the effect after being modified using the method in the present invention：Calibration result is good.

Brief description

Fig. 1 is that the angle of spheric coordinate systems of the present invention represents schematic diagram；

Fig. 2 is camera of the present invention shooting effect in an inclined state；

Fig. 3 is the effect after Fig. 2 is modified using the method in the present invention.

Specific embodiment

The present invention will be further described below in conjunction with the accompanying drawings.

The present invention proposes a kind of method of panorama camera automatic stabilisation shooting visual angle.Number based on inclination measuring sensor According to the panoramic picture that shooting is obtained carries out global change's mapping algorithm, is automatically corrected as panoramic picture by software mode The vertically image at upright visual angle, thus be still provided that the panoramic video of good viewing effect in the case of shooting unsteady attitude Or image.

Hardware plan：The present invention, on the basis of the hardware plan of common panorama camera, needs extra interpolation gradient measurement Sensor, common are three-axis gyroscope, for measuring the angle of camera axis and gravity vertical, i.e. camera gradient.Remaining is hard Part scheme is identical with common panorama camera.

Method is realized：

In panoramic camera, when shooting unit is placed on clinoplain, the image of multiple camera acquisitions is according to former The panoramic mosaic image that the spherical projection matrix beginning maps gained can not keep " upright " vision well, panoramic mosaic image Certain distortion can be produced, this distortion possesses certain rule.

Image unit integral inclined to a certain degree when, its projection sphere is actual to there is certain rotation with respect to scene in kind Turn or tilt, this deflection can be given by three-axis gyroscope, usual gyroscope provides two deflection angle data (θ, φ), The angle method for expressing of spheric coordinate systems is as shown in Figure 1.Wherein φ is the angle of OP and plane XOZ, and θ is OP face projection under the line Angle with OX.

Fig. 1 spheric coordinate systems angle method for expressing schematic diagram, in figure sphere the coordinate of point P be (θ, φ) when gyroscope inclined When gyration θ ≠ 0 and φ ≠ 0, the equatoriat plane makees the rotation that angle is φ, and rotary shaft is with vectorAnd y-axis Place plane crosses the vertical line of the centre of sphere.This spin matrix can be written as

Wherein vectorIt is represented byThen cross product

Make quaternary number

Quaternary number form formula can be converted into using triangular equation

Wherein

Therefore have

$R\left(q\right)=\left[\begin{array}{ccc}1-2(y^2+z^2)& 2(xy-zw)& 2(xz+yw)\\ 2(xy+zw)& 1-2(x^2+z^2)& 2(yz-xw)\\ 2(xz-yw)& 2(yz+xw)& 1-2(x^2+y^2)\end{array}\right]$

CauseHave

Then

$R\left(q\right)=\left[\begin{array}{ccc}1-2z^2& -2zw& 2xz\\ 2zw& 1-2(x^2+z^2)& -2xw\\ 2xz& 2xw& 1-2x^2\end{array}\right].$

There is this spin matrix it is possible to be calculated for pixel coordinate.Assume that the width of panoramic picture covers θ:0～ The sphere longitude range of 2 π, height covers φ:The sphere latitude scope of 0～π, input picture and the same length and width of output image (w, h), Any pixel in output imageCan be corresponding to point on projection sphere by spherical projection relation

Wherein f1 is to throw Shadow spherical radius.

From shooting unit spin matrix R (q) obtaining above, project point P1 on sphere and inversely deflect gained projection ball Another point P on face₀(x₀,y₀,f₀), and

By P₀Can obtain in panoramic picture with pixelCorresponding sub-pixel location

$(x_0^{\mathrm{\θ}},y_0^{\mathrm{\φ}})=\left(atan2\right(f_0,x_0),atan2(\sqrt{{x_0}^2+{f_0}^2},y_0)$

Thus, you can according to sub-pixel location in input picturePixel value, can correspond in output image Arbitrary coordinate positionThe value of upper pixel.According to gradient parameter, panoramic video/image that panorama camera is shot is carried out Attitude rectification, is revised the image effect shooting during attitude upright to camera.

Above content is to further describe it is impossible to assert with reference to specific preferred implementation is made for the present invention Being embodied as of the present invention is confined to these explanations.For general technical staff of the technical field of the invention, On the premise of present inventive concept, some simple deduction or replace can also be made, all should be considered as belonging to the present invention's Protection domain.

Claims (4)

1. a kind of automatic stabilisation visual angle of panorama camera method it is characterised in that：Integral inclined to a certain degree in shooting unit When, projection sphere is actual with respect to scene in kind, certain rotation or inclination occurs for it, be given two deflection angle data (θ, φ), under spheric coordinate systems, wherein φ is the angle of OP and plane XOZ, and θ is that face projects the angle with OX to OP under the line；On sphere The coordinate of point P is (θ, φ), and when deflection angle θ ≠ 0 and φ ≠ 0, the equatoriat plane makees the rotation that angle is φ, this rotation

Torque battle array can be written as

Wherein vectorIt is represented byThen cross product

Make quaternary number

Quaternary number form formula can be converted into using triangular equation

Wherein

Therefore have

$R\left(q\right)=\left[\begin{array}{ccc}1-2(y^2+z^2)& 2(xy-zw)& 2(xz+yw)\\ 2(xy+zw)& 1-2(x^2+z^2)& 2(yz-xw)\\ 2(xz-yw)& 2(yz+xw)& 1-2(x^2+y^2)\end{array}\right]$

CauseHave

Then

$R\left(q\right)=\left[\begin{array}{ccc}1-2z^2& -2zw& 2xz\\ 2zw& 1-2(x^2+z^2)& -2xw\\ 2xz& 2xw& 1-2x^2\end{array}\right].$

2. a kind of automatic stabilisation visual angle of panorama camera according to claim 1 method it is characterised in that：Described deflection Angle-data is given by three-axis gyroscope.

3. a kind of automatic stabilisation visual angle of panorama camera according to claim 1 method it is characterised in that：

The equatoriat plane makees the rotation that angle is φ, and described rotary shaft is with vectorCross the centre of sphere with y-axis place plane Vertical line.

4. a kind of automatic stabilisation visual angle of panorama camera according to claim 1 method it is characterised in that：Assume panorama The width of image covers θ:The sphere longitude range of 0～2 π, height covers φ:Sphere latitude scope, input picture and the output of 0～π The same length and width of image (w, h), any pixel in output imageCan be corresponding to projection sphere by spherical projection relation Upper pointWherein f1 is projection ball Radius surface；From shooting unit spin matrix R (q) obtaining above, project point P1 on sphere and inversely deflect gained projection ball Another point P on face₀(x₀,y₀,f₀), and

By P₀Can obtain in panoramic picture with pixelCorresponding sub-pixel location

Thus, you can according to sub-pixel location in input picturePixel value, obtain in corresponding output image and arbitrarily sit Cursor positionThe value of upper pixel；According to gradient parameter, the panoramic video that panorama camera is shot or image carry out attitude Revise, revised the image effect shooting during attitude upright to camera.