Hi

We haven't seen the panorama, so we can't possibly know what he did.

"My assumption is that he has kept the camera as the same distance away from the subject and at the same height whilst taking overlapping photos when walking down the street.  This is the only way I can think of how it was done but is this viable to do with APP as well?"
If his pano looked like this, then that is called an orthogonal projection panorama, where you move the camera parallel to the scene. It's possible to do this in Autopano, although it will require some postprocessing to remove bad stitches. You will notice that these types of panoramas typically don't contain much of the ground, because its that part of the pano where the most serious stitching issues appear. Easier just to crop it off.

Here are two orthogonal panos I shot with my cellphone and stitched with APP-1.4.2. Notice the errors in the tiles.
http://www.autopano.net/forum/t3583-ort … hone-panos

The further away from the subject you are (the buildings or the wall in this case), the better.

Ideally you would use a sensor with only 1 column of pixels and move it parallel to the scene, like a line scan camera ("1" dimensional - e.g. 4000 pixels high but only 1 pixel wide). Since you're using a "2" dimensional sensor, I found that shooting many shots close to each other, with 80% or 90% overlap, and then batch cropping out just the central parts of all images (I used imagemagick in linux) worked quite well, since Autopano would only place checkpoints in the centers of what used to be far wider photos.

UK Pano wrote:

My assumption is that he has kept the camera as the same distance away from the subject and at the same height whilst taking overlapping photos when walking down the street.  This is the only way I can think of how it was done but is this viable to do with APP as well?

I am using panoramic photography as my subject matter for my college course and this has caught my interest as another possible subject to try out and would appreciate the forums thoughts, directions and suggestions!

Thanks in advance if you can assist 

DrSlony  wrote:

Ideally you would use a sensor with only 1 column of pixels and move it parallel to the scene, like a line scan camera ("1" dimensional - e.g. 4000 pixels high but only 1 pixel wide). Since you're using a "2" dimensional sensor, I found that shooting many shots close to each other, with 80% or 90% overlap, and then batch cropping out just the central parts of all images (I used imagemagick in linux) worked quite well, since Autopano would only place checkpoints in the centers of what used to be far wider photos.

It easy to demonstrate that to get a perfect stitch is impossible but in a single case: the subject is completely flat. Plane subjects (like a painting on a wall or a paper sheet in a scanner) are the easiest subjects but what matters is this: all the objects which are seen in two adjacent images should be at the same distance from the camera.

Even using a sensor with only one column of pixels (such cameras exist and are used for aerial views) distance variations cause problems when the subject is not flat. Imagine for example you are using such "slit" camera to photography a 100 feet long row of trees against very distant mounts: because the camera orientation would not change the very same part of the mounts would be recorded between the trees so that the result would be quite strange!

In a street it's quite easy to get very decent results when shooting the building façades from the opposite sidewalk but crossroads want many manual adjustments. River banks are another great subject but bridges are then a perfect nightmare!

Several fine examples on this Web page http://www.animatif.com/labo/linear-panoramas.htm by Guillaume Fulchiron

By reading this paper http://research.microsoft.com/en-us/um/ … things.pdf (where I skipped over the maths !) one can find nice examples and a clear description of the fundamental principles.

hankkarl: very good idea! Seems so obvious now that you said it, but I hadn't thought of that before! :]

GURL: "Imagine for example you are using such "slit" camera to photography a 100 feet long row of trees against very distant mounts" I can imagine the result, and I would love to see it! Hmm well perhaps very distant mountains would be boring because you'd just have a horizontal smudge behind the trees - if you moved 10 meters parallel to them, you'd have 10 meters worth of trees but possibly the same identical column of pixels for the mountains, but if instead of moving along a straight line you moved along a curve so you wouldn't be scanning the exact same part of the mountains in the background as you move... interesting! Anyone with a line scan camera reading this willing to try? :]

UK Pano: never underestimate how complicated something easy can be! ;]

hankkarl wrote:

Dr. Slony:  the cropping idea would be very nice if you took frames from a video.  This may be another thing for the future--to have an import video feature with a center crop.  IIRC, its been suggested before.

There was once a program that would stitch/generate a pano from video. IIRC it was called Videobrush - I believe it disappeared into the black hole called IPIX.
http://www.encyclopedia.com/doc/1G1-20793158.html
http://www.steves-digicams.com/news/pic … tions.html

IIRC the originators were ex-Xerox people.

Last edited by mediavets (2009-12-03 18:23:46)

I think it'll work. If the weather is good the upcoming weekend, i can test it.  I  tape a Flip-Video cam at a side window of may car and shoot a sequence. I can do it at different speeds. The Flip cam captures HD video at 30 fps. So 5 seconds give already 150 pictures. But maybe reducing the framerate in postproduction would do the tric. I already tried it once  with a different idea in mind ( see http://www.autopano.net/forum/t7732-just-testing ) and it worked quite well. With MPEG Streamclip i can reduce the framrate to maybe 10 fps. It certainly depends on the speed of the car and on the overall length of the object to be panoramarized.

DrSlony i tried it with reducing the frame rate and it wasn't a good result. I already tried the the method you suggested, discarding images from the sequence. This is probably the better way. I have a short sequence and the extracted frames uploaded for all of you who want to try it out (http://www.spherorama.de/Test-Movie/App-Pano.zip). I tried to stich it but I think there is too much parallax in the sequence.

See example 1 rendered Pano out of APP and picture 2 screenshot from APP. I noticed that closer objects have less parallax than objects farer away.

Last edited by spherorama (2009-12-05 15:51:54)

I have tried the single column of pixels thing, having shot HD video (camera oriented vertically) out the window of my car. The thing is that further away objects get very blurred as they are moving less than the nearby objects.

Looks like Olympus liked the idea ! http://www.olympus.eu/penstory/

Yay!  Finally found the panoramic that I was referring to in my original post.

http://www.stevebloomphoto.com/books/tr … _page.html

If printed 1m tall, it would be 40m long!

Wow!  Thanks for the links Klaus.

Tomas' architectural images are amazing and it is a small world as I am studying architectural photography/photographers as part of my degree course and now have another photographer that I can include in my studies