My Autopano Pro forum

I don't want to manually compete with SIFT when a large number of CP per link (e.g. 50 CPs) is involved:
- I would like an easier way to instruct APP and/or SIFT to place more CPs here (e.g. skyline) and to remove any CPs there (e.g. moving clouds, tree branches on a windy day, parallax errors prone locations, etc)
- I would like an easier way to delete "long links" (e.g. corner to corner link on fisheye images or very large number of links when using braketing.)
- I would like an easier way to move unlinked (or "miss-linked") pictures manually.

Those matters having been settled, then, if it's possible to reduce the number of CP under 10 per link or possible to implement "heavy weighted manual CP"...
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A moins de leur donner un poids plus elevé (10 fois plus ?) je n'ai pas envie d'entrer en compétition avec SIFT même si je suis persuadé (à tort ou à raison, peu importe) d'avoir la patience et l'expertise nécessaire pour les placer avec une précision remarquable aux endroits les plus judicieux. (Par contre je me vois très mal en train d'expliquer comment il faut faire pour bien le faire !)

En plus, une fois en mesure d'imposer mes propres CP, je ne vois pas pourquoi je ne pourrais pas aussi imposer ma propre manière de faire pendant l'optimisation (il est un peu trop "auto" cet optimiseur, non?)

Avec PTassembler et avec PTgui (jusqu'à il y a quelques mois c'est PTgui que j'utilisai pour assembler mes panos fisheye) il s'agit de travailler avec au maximum 10 CPs par lien et un nombre restrent de liens, autrement dit de travailler CP par CP.

Avec APP c'est une gestion beaucoup plus globale qui me semble adaptée. J'ai envie de dire que c'est comme la différence entre les 3 ou 4 chèvres qu'on promène au bout d'une chaîne comparées à un troupeau de plusieurs centaines de moutons qu'on conduit avec des chiens de berger ( je trouve l'image un peu trop bucolique, mais je n'en trouve pas d'autre. Peut-être faudrait il invoquer la loi des grands nombre et les calculs de probabilité...)

Que les chiens de berger d'APP aient besoin d'être mieux choisis et mieux dressés me semble évident...

Pour ce qui est de faire aussi bien que PTgui sur des photos au fisheye après la pose des deux premiers CP: c'est évidemment possible - y'a pas de raison - mais je doute que ce genre d'interface puisse être conçue en 5 minutes.

On peut imaginer un Manupano Pro en plus d'Autopano PRO (par exemple à cause du "sic" de Johnh dans le dernier post de ce thread http://www.tawbaware.com/forum2/viewtopic.php?t=2719 mais avant je recommande vivement la lecture des aventure d'Eastman. Les pros de la photographie de l'époque (sur plaque de verre, au colodion humide, avec tente-laboratoire à transporter su place) s'en moquaient. Eastman en a déduit qu'il devait vendre ses Brownies et ses pellicules aux femmes et aux enfants d'abord et ça lui a plutôt bien réussi, non?

I like the way hugin lets you add manual CPs  especially the checkbox to say "use an assistant to fine tune the points".

Perhaps an option to let the user say "a manual CP is worth xxx automatically generated CPs"

I like the idea of  "auto-delete long links" 

I'd like an auto way to generate CPs based on contrast or edge finding, rather than SIFT.  That is, automatically add CPs based on some algorithm closer to human vision.

I like GURLs idea about keeping CPs off clouds and putting them on the horizon, one way to implement it is to show all the CPs on the main window when in the CP editor (we'd need an option "show links or show CPs".)  And I'd want to be able to delete CPs on that main window so that its easier to delete CPs on clouds, water, etc.   An add function could add CPs on a user-specified area (draw the box, hit the add CP button) to put CPs where you want them. -- A way to automatically remove CPs from clouds, waves and moving objects is probably more of a dream than a reality.

Another option would be for APP to give a better indication of "goodness" of the link.  This can be done by taking two pictures, finding the overlap based on CPs, and doing some math on the pixels in that overlaped part.  The math may be to subtract one pixel from its corresponding pixel in the other region for all the pixels, then find the average of the differences of all the pixels, and give an RMS value of all the differences from the average.  APP could give the user an option to delete links where the overlap correspondence is less good.  This could also shown visually by finding subtracting each pixel from its corresponding pixel to give a picture of the differences in the region, then color-coding the variation from the average difference for each pixel.  This resulting map could be used as a transparent overlay on the pictures to show what items don't line up.

Last edited by hankkarl (2007-11-06 15:50:30)

I agree that a feature to manually place a CP in an exact spot would be useful sometimes.

Also what would be great would be an option to prioritise the correct alignment of 'narrow & long' areas. Let me elaborate:
This would be very usefull for panos with cables, tiles, wooden beams, wall edges, girders, etc. APP would add extra priority to CPs that are placed along long but thin areas, like those examples, and do its best to align those areas between shots since misalignments between those parts would be most visible.

Most often the parts of a panorama that are incorrectly aligned, and parts where incorrect alignment is most visible, are edges. I was wondering about using some form of edge detection to help properly align images. I see two advantages to using this:
1- some edge detecting algorithm, or simply a blur/contrast combination like in photoshop/gimp, find edges. Then the SIFT algorithm places a high priority on all CPs located along these edge lines.
2- the edge lines can serve as a guide as to whether the images were correctly aligned. It finds a common edge pattern in the two images and then, after stitching the two images and deciding at which exact point smartblend will chop off each image's overlap, it checks if this pattern has any sudden 'interruptions', if it has been correctly overlayed in common parts. If the edge line does suddenly stop in the stitched image but does NOT stop at this point in the source image, then a bad stitch alarm is raised.

It all is nice and easy here, and I have no experience in these kinds of things, but perhaps the idea could be used to solve some frequent problems?

Some sample screenshots of how this might work:
1 - the original image. I cut it into two images with overlap.
2 - an example of how APP could have detected CPs.
3 - the results of these CPs gives a bad stitch, especially visible in the cables.
4 - APP checks edges if there are any sudden interruptions. It finds several broken edges in places where they were not broken in the original left source photo. A bad stitch alarm is raised,
5 - APP gives priority to these places,
6 - and tries to find some CPs in these broken edge areas.
7 - reoptimized, and now the stitch is good.

Last edited by DrSlony (2008-07-06 00:10:01)