bmaltais's dashboard

Shinzann, I won't rule it out, but to be brutally frank, I think the chances aren't good. This has nothing to do with operating system partisanship-- we're very keen to do the Mac version simply because lots of people with Macs are passionate photographers and early adopters of visual technology. We know that it hurts the community as a whole for there not to be a Mac implementation. But the cost to us of supporting additional platforms in binary code is substantial-- we have a small team, and such support must be balanced against lots of great features (for the rest of us) we could build with comparable resources. In other words, it's all about a kind of integrated value over the community. It's a tradeoff-- wider, or deeper? We don't imagine that a huge segment of our potential community works exclusively on Linux boxes. But if you have data that might cast doubt on this intuition, do please share.
I'm more optimistic about PowerPC, because as far as I understand the APIs and compilation tools are identical to the new Mac, so the cost may not be very high. But I'm not sure.

This is really interesting. So essentially the HD resolution of 2 megapixel is just fine for creating synth. I guess you are limiting the resolution to 1.5 mega pixels to reduce computing time on the client. Striking the right balance between accuracy and CPU time is a real science.

Is there a technical reason for not allowing one to do a synth in smaller batch of say... 5 pictures, and then adding 5 more, then five move when computation is done for the previous five? Is it something doable? – bmaltais, on August 26, 2008 12:04

I am not sure but if it has been more than 12 hours you can probably forget those synth. I, for myself, have at least 3 synth that successfully uploaded but never showed. I think I tracked it down to missing EXIF data in the pictures used to make those synth. All my synth that have EXIF data in the pictures have shown just fine... Only the ones with EXIF data missing are not showing even if they appear to have synthed right.

OK, I think I have isolated the issue with my HD based synth. I had to add some more EXIF data to each jpeg before creating the synth. Essentially I took an actual picture in HD format with the Canon HV20 and extracted the EXIF data from it using exiftool.

I then apply this same info to all my jpeg using again exiftool:

exiftool -TagsFromFile canonhv20.xmp <dir>
rm <dir>/*.jpg_original

I then use those files to create the synth. With that no more "Publishing bug".

You can see a sample of a synth created this way below:

DeckHD1080p: Made by outputting at 1 picture per sec.
ToyHD1080p: Made by outputting at 3 picture per sec... very detailed.

If only I could now keep adding to my synth time after time I could build a very high resolution synth containing 1000s of pictured from HD capture.

Photosynth allow you to turn you HD footage into a 3D world. While standing in photosynth at the HD camera location and doing a left to right pan will give you the impression of being virtually behind the camera. Very cool.</dir></dir>

OK, I think I am on something. I noticed that all my synth made purely from my Canon Rebel digital camera will process and show up on Photosynth right away. Those pictures all have proper EXIF data in them.

All the synth based on jpeg missing EXIF data are not showing after being uploaded... so my guess is that somewhere in Photosynth it is expecting EXIF in pictures... and if it is missing it just goes nowhere.

Look at your log files for lines about missing EXIF data. All my successful synth are exempt of errors regarding EXIF. All the ones that won't show up on the sites exhibit missing EXIF errors.

OK, it is now 30 hours for one of my synth and it is still not showing ;-(

OK, I created my test synth today from a 9 minutes sequence from my backyard. I had set the camera in 24p mode with a fixed 1/500th shutter speed. That gave me a 13,000+ potential pictures to build my synth from... So clearly this is too much to handle.

For those curious here is my workflow on a Mac to publish a synth via a PC:

1. I imported the video from the camera over firewire by using DVHScap from the Apple Firewire SDK

2. I converted the raw .m2t file to something Quicktime can handle by using mencoder (google for it if you want) with the following command:

./mencoder synthtest.m2t -mc 0 -noskip -fps 30000/1001 -delay -0.222 -oac pcm -vf pullup,softskip,harddup,scale=1280:720 -ofps 24000/1001 -ovc lavc -lavcopts vcodec=mjpeg -o synth.avi

Notice that I reduced the resolution from 1080p to 720p to save some space... might try it later will full res to see if it will improve the synthyness.

3. I opened the resulting synth.avi in Quicktime Pro and used the export function to output as "Movie to Image Sequence" as .jpg at 1fps (1 image per second of source video). This produced 585 pictures in a folder.

4. I select them all and viewed them in "Preview" to delete the pictures I tought where not needed until I got down to about 288 good ones.

5. I select the 288 pic and copied them in a new folder that I putted on a network share.

6. I go to my Vista MCE PC where I openned Photosynth and created a synth from the pictures in the shared folder.

7. Wait about 30 minutes for syhthing to complete

8. Look at log to see if all is good... This particular test is apparently only 47% synthy ;-( But I know it is 100% sinthy ;-) so somewhere the algorythm is not registering things correctly.

9. Wait for synth to show up on web site. It's been 1 hour and I am still waiting.

Note: Since I am generating my pictures from a movie sequence there is not exif data to get the camera info from and Photosynth spit a message about that in the log for every picture... but apparently can do without it. Cold this be a problem on the web site? Could this be why my synth don't show up?

I am wondering if the fact that none of the pictures part of my synth have exif data could be part of the issue. The three synth that came from Digital photo Camera all showed up fine on photosynth web site... but all the ones from my HD camera (no exif data since they are from video stills) are not showing yet.

And if photosynth could do something like seti@home and come up with a distributed client that could wait for work to process then the whole thing could be distributed.

Upload a picture from your phone to a group effort and it get included right away via distributed network computing... so no need to only use local PC CPU.

Just checked and still no sign of my synth.

I also think that higher res is not necessarily required. A good size picture in large quantity should compensate for the lack of pixels. Simply make sure to snap a few good pictures up close to some objects for details. Especially given storage space and memory requirement on the client end.

On cool thing could be a distributed photosynth client that allow photosynth to leverage idle CPU cycles on users PC to synth large amount of pictures together. This could be done on a group basis where users allow other users in that group to use free CPU cycles to help compute synths.

Interesting abstract. Could apply to how photosynth could leverage video key frames to do the matching on it own and then use photosynth spacial algorythm to produce the 3D scene from video in an efficient manner. This would be great. In the mean time a human can do the heavy work by manually selecting picture frames from the video and use that to do the synth... minus the possibility of the picture to picture animated transition ;-)

This would essentially allow photosynth to recreate a 3D scene from a good HD video source.

Oh, one thing that come to mind is that since photosynth use picture still at it's heart it will be essential to crank up the shutter speed to a high enough value (like 1/500th +) to ensure that the captured frames are not blurry and are actually as sharp as can be. Cranking up the shutter speed will also benefit photosynth by increasing the depth of field such that more things are in focus.

Another thing to note is that you will want to use an HD camera that can do "progressive" capture like the HV20. Those Sony that only 1080i at 60fps are no good for this as you will get pictures with a bunch of interlace artifacts... unless you export as individual half frames and resize to full frame at the cost of loosing half the resolution ;-(

I am not home right now... The 1st synth completed last night before going to bed and was still not available on the web site this morning... So I ran it again under a different name and it still is not showing.

I cant check the log as I am at work... Oh... what am I doing on this forum then... back to work ;-)

Hello Blaise. Gret work by the way! I think video (especially HD) can be used for photosynth creation in quite a nice way. I am actually going to do some test today after work by taking an HD movie in progressive mode (full picture for every frame) and turn it into a bunch a individual picture still. As I walk with the HD cam in the scene I will record tens of thousands of pictures of the scene in the 3D space. Those 1000s of pictures can then be turned in a 100% synthy photosynth of the scene. The resolution shortcoming of HD camera (1920x1080) will be compensated by the shere number of pictures taken by it. I do not say that I will use every pictures frame as it would be computationally impossible right now... but I am sure some algorythm could be use to minimize the impact of each frames in the over all synth as they share so many commonalities. I started a topic on this here: http://getsatisfaction.com/livelabs/t... – bmaltais, on August 22, 2008 13:42