Thread Subject: angle, rotation, transformation

Hi all,

I have two views of the same object containing 10 dots.
First view is an image of MxN. M>N.
In second view is rotated (by 90degree) and object looks smaller because of NxM settings.
In view-I object is at the center while on view-II object is a bit shifted.
I got information of 10dots in both images.

How i can get point to point correspondence in both images?
How one can find translation, rotation, angles etc information?
How one can make 3D points?

thanks in advance.
regards,
Image Vision.

"imagevision" wrote in message <jgoei1$ild$1@newscl01ah.mathworks.com>...
> Hi all,
>
> I have two views of the same object containing 10 dots.
> First view is an image of MxN. M>N.
> In second view is rotated (by 90degree) and object looks smaller because of NxM settings.
> In view-I object is at the center while on view-II object is a bit shifted.
> I got information of 10dots in both images.
>
> How i can get point to point correspondence in both images?
> How one can find translation, rotation, angles etc information?
> How one can make 3D points?
=============

It's a bundle adjustment problem. Here's a reasonable starting point

http://en.wikipedia.org/wiki/Bundle_adjustment

But if you already know the characteristics of your camera, and you know EXACTLY how the camera moves between the 2 views, you should have enough information to find, for each dot and each view, a 3D line on which the dot lies. The intersection of the two lines will pinpoint the dot's 3D location.

Hi
Thanks,
The angle between two cameras is of 90 degree.
could any body suggest me matlab-code for this problem?
thank in advance.
regard,
from
Image vision.

"Matt J" wrote in message <jgomkp$edr$1@newscl01ah.mathworks.com>...
> "imagevision" wrote in message <jgoei1$ild$1@newscl01ah.mathworks.com>...
> > Hi all,
> >
> > I have two views of the same object containing 10 dots.
> > First view is an image of MxN. M>N.
> > In second view is rotated (by 90degree) and object looks smaller because of NxM settings.
> > In view-I object is at the center while on view-II object is a bit shifted.
> > I got information of 10dots in both images.
> >
> > How i can get point to point correspondence in both images?
> > How one can find translation, rotation, angles etc information?
> > How one can make 3D points?
> =============
>
> It's a bundle adjustment problem. Here's a reasonable starting point
>
> http://en.wikipedia.org/wiki/Bundle_adjustment
>
> But if you already know the characteristics of your camera, and you know EXACTLY how the camera moves between the 2 views, you should have enough information to find, for each dot and each view, a 3D line on which the dot lies. The intersection of the two lines will pinpoint the dot's 3D location.

"imagevision " <csphysics@yahoo.com> wrote in message
news:jgongt$hgs$1@newscl01ah.mathworks.com...
> Hi Thanks,
> The angle between two cameras is of 90 degree.
> could any body suggest me matlab-code for this problem?

In general, I think the problem as described is impossible to solve.

plot3([1 0 0 1], [1 1 0 0], [1 1 1 1], 'o');
xlabel('x');
ylabel('y');
zlabel('z');
view([90, 0])
pause
view([0, 0])

In each of the views above, two of the four distinct points are concealed
behind other points. We need to do something like looking from above to see
all four.

view([0, 90])

--
Steve Lord
slord@mathworks.com
To contact Technical Support use the Contact Us link on
http://www.mathworks.com

"imagevision" wrote in message <jgongt$hgs$1@newscl01ah.mathworks.com>...
>
>
> could any body suggest me matlab-code for this problem?
=================

The line of sight to the camera for each point and camera positions will obey equations

C*x=d

where C is 2x3 and x is an unknown point on the line of sight. You have 2 camera positions so the intersection of the lines of sight is given by the 4x3 system

[C1;C2]*x=[d1;d2]

All the code you need to solve for the 3D location of point is therefore,

x=[C1;C2]\[d1;d2]