[OpenDroneMap-dev] OpenDroneMap-dev Digest, Vol 2, Issue 11

[Cole]

What information do you have?  I don't understand what you are trying to
do.  If you are trying to find the camera position from matched keypoints
on different images you need to perform homography and have >= 4 matching
keypoints.  http://en.wikipedia.org/wiki/Homography_%28computer_vision%29

If you are trying to find the distance to a single point you need the
camera position and where the X, Y of the point in at least 2 frames.  Take
a look at epipolar lines, and well as the homography link.  There is also
an excellent book called multi-view geometry.

On Mon, Mar 30, 2015 at 3:01 PM, <opendronemap-dev-request at lists.osgeo.org>
wrote:

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> Today's Topics:
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>    1. Bundler transformation from image to world        coordinates
>       (Bruno Oliveira)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Mon, 30 Mar 2015 19:19:02 +0100
> From: Bruno Oliveira <bruno.manata.oliveira at gmail.com>
> To: opendronemap-users <opendronemap-users at lists.osgeo.org>,
>         opendronemap-dev at lists.osgeo.org
> Subject: [OpenDroneMap-dev] Bundler transformation from image to world
>         coordinates
> Message-ID:
>         <
> CAO-SbSvSd50a_XOoBk80-cJ+E09dF_VxNZNrrYYzeshx1gd9VA at mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> Hello,
>
> does anyone know how to do the inverse bundler transform?
> This is waht is in the manual (
> http://www.cs.cornell.edu/~snavely/bundler/bundler-v0.3-manual.html) :
>
> *P* = *R* * *X* + *t*       (conversion from world to camera
> coordinates)*p* = -*P* / *P*.z        (perspective division)*p*' = *f*
> * r(*p*) * *p*   (conversion to pixel coordinates)
>
>
> This explains how to transform a world point X to camera coordinates.
>
> But how do I do the inverse transformation? (for instance, how do I
> get thr x point?.....)
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