To manage photos overlapped in miscellaneous way

[feryllt]

Dear Hugin Staff,
I would want to propose to you an user interface and a simple algorithm in order to simplify the creation of control points with photographies that overlap in miscellaneous way.

We suppose of to have taken the photos of a panorama with a not-wide angle optic. Therefore, for being able to cover the vertical extension, three series have been made, heading up, low and to the center.

The photos that are obtained not only overlap from right towards left (or left to right) but also up and down. I have noticed that autopano does not manage such situation at best.

Currently I have resolved the problem selecting the overlapping photographies by hand and then launching every time the creation of the control points. It works well, but it is boring and it is easy to mistake.

I have thought, therefore, that he would be interesting to have a section of hugin where to be able to indicate which pairs of photographies are overlapped, so that hugin can, automatically, launch autopano on the correct sets of overlapping photographies.

For an example I attached a proposal of interface for being able to perform this selection.

Obviously the more problematic part is managing the undirected graph that it is obtained with this method.
I would propose to proceed with the following algorithm:

Prerequisite: we have the graph where node(n)='photo n' and arc(a,b)='photo a and b are overlapped'. The graph is created using data supplied by user using the proposed interface.

  for each photo p
    clear set S
    insert p into the set S
    for each neighbor n of node(p)
       insert n into the set S
    launch autopano on photos in S

where 'neighbor' represents a metric on the graph. The simplest one is consider 'neighbors' of node(p) those nodes m for which exists the relation arc (p, m).

Obviously such operation is not necessary if the user not have necessity of a thus precise control of the creation of the control points.

Hoping of being be useful to you and to have marked an interesting request,
Yours respectfully
Filippo Pagin

[feryllt (feryllt-users)]

The file photo_neighborhood_selection_interface.pdf.tar.gz was added: This file PDF contains two proposal of interface for the manual selection of neighborhood of the photos. (two pages, one for each proposal)

[feryllt (feryllt-users)]

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the submit process has lost indentation. The correct algorithm is this:

. for each photo p
. {
. clear set S
. insert p into the set S
. for each neighbor n of node(p)
. {
. insert n into the set S
. }
. launch autopano on photos in S
. }

[Bruno Postle (brunopostle)]

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Independently, Seb Perez-Duarte and myself have been investigating drawing undirected graphs of real hugin .pto projects. This has been suggested in the past as the basis of a new interface for hugin, you can see some example graphs here:

http://www.flickr.com/photos/sbprzd/tags/graphviz/
http://www.flickr.com/photos/36383814@N00/tags/graphviz/

My 'ptograph' tool for creating these can be found in panotools SVN, it will be in the next release of the Panotools::Script perl module.

[feryllt (feryllt-users)]

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I have observed the link and I have tried “ptograph”. Sure interesting, however is clearly that my proposal was different. Not to generate the graph of the overlaps found by autopano but to supply to the user an interface in order to suggest to hugin on which photos executing the search of the control points.

This effort is not much too for a human being, if supported from “a comfortable” interface.
Moreover, the possibility to indicate by hand the relations between the photos allows to reduce the generation times of the control points because autopano would act exclusively on a set of photographies that surely are overlapped. Avoiding, therefore, to engage resources of calculation in the verification of not meaningful pairs. Problem this that attract attention in the case of many photographies.

However I do not know the deep operation of autopano. It could be more meaningful to modify autopano so that it can accept the graph “of the suggestions” and act in "intelligent" way on the base of it.

I admit that if had time and if it were useful, I would want to participate to the development. However I am in order to begin a plan on the GNU tool of code coverage (gcov) and I'm fear that this will take to me very many time.

Best regards,
Filippo Pagin

[Pablo d'Angelo (pablo.dangelo)]

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Hugin already has both code to calculate control point connection and image overlap graphs, but they are not used in the GUI.

It is planned that restricting image matching to neighbouring images is part of the feature matching project in the google summer of code.

 Pablo

[tmodes (tmodes)]

Something similiar is already in repository with pre-aligned cp detector setting.