Messages

16

Face and Body Scanning / Re: Samsung NX1000

« on: February 04, 2013, 05:39:45 PM »

Everybody's comments are right on. 

From what I've learned from multiple sync for Canon cameras, the shortest lag time between single shots is never shorter than what is acheived with continuous ("burst") mode; i.e., 8 fps your NX1000.  The real limitations, as Lee pointed out, is the time it takes to write to the disk (perhaps related to maximum number of shots that at a rate that you can get consistent results with continuous mode), as well as the recycle time for flash.

Andy, I wonder if a rate of 2 or 3fps would be sufficient for a lazy-susan/camera dolly approach, (assuming we get the non-rigid registration working).  Even if you could get sufficiently fast flash recycle times, at one "chunk" taken every 30degrees, for example, that would be 15rpm.  (30degrees/360degrees per revoution x  3 frames per second= .25 revolutions/second, which multiplied by 60 seconds/minute gives 15rpm).

At 8 frames/second, that would be 40rpm, which seems pretty fast.

Just my 2 cents worth...

Harold

17

Face and Body Scanning / Re: Would this work? Video, turntable solution

« on: February 04, 2013, 07:28:56 AM »

Wow, that part about hauling the light tent around in a circle is creative!  I'm looking forward to see your build and the agisoft results.

It's amazing how bouncing ideas back and forth with other people speeds up the process.  Best of luck!

Harold

18

Face and Body Scanning / Re: Would this work? Video, turntable solution

« on: February 02, 2013, 06:42:32 PM »

I know exactly how you feel, Andy, about the euphoria.  Lee, you have certainly been an inspiration for all of us, especially how you've figured out how to overcome the many technical problems associated with live scans.  Interesting about Hao Li's work with Arctec, although it's still a bit too expensive for my budget. 

Speaking of problems of of the lazy-susan, I'm planning to use a camera dolly on a circular track that goes around the model, always pointing to the center to capture a (as still as possible) model.  I'll let you know how that works.

I'm using 6 Canon SX130s (got refurbished ones for about $120 each on ebay, sometimes they're cheaper).  With a lot of overlap, I'm happy with the results of inanimate models.

Sync is a challenge; I've been fairly successful using the CHDK, which most Canon point-and-shoot cameras are able to use as a multiple camera sync hack.  http://chdk.wikia.com/wiki/CHDK
Using USB cables, I can get the 6 shutters to remain open for 1/10 second, and now I'm working on some circuits to fire the studio strobes during that 1/10 second.

BTW, Andy, there are some useful posts in their forum about writing a motion trigger for lighting capture that discusses the issues you raise.  Not sure about applicability to DSLRs, however.

It's great to know there are others working on the same challenges!  Looking forward to further collaboration.

Harold

19

Face and Body Scanning / Re: Would this work? Video, turntable solution

« on: February 02, 2013, 03:30:17 AM »

Andy,

I think your suggestion about using non-rigid registration to align meshes that you get from scans using less than 10 cameras is quite brilliant, as a low-cost alternative.
 
I've been corresponding with Hao Li about using his BeNTO3d software (check out http://www.bento3d.com/BeNTO3D/BeNTO3D_-_teaser.html )
He's seems pretty willing to help, but I haven't given him very good sets of data yet.
Still working on my rig.

Have you tried some of the non-rigid registration programs that have been developed for medical research?  3D Slicer seems the most user-friendly, (http://www.slicer.org/ )
but there are also a few others, like elastix
( http://elastix.isi.uu.nl/index.php. )

Keep up the great experimentation!

Harold

20

Face and Body Scanning / Re: Scanning people: Tips needed

« on: April 30, 2012, 04:12:27 PM »

Mark,
I've never used the CHDK hacks for Canon cameras, so I can't say how well they work.  But you might be interested in trying this strategy for some lower cost cameras:

http://chdk.wikia.com/wiki/CHDK

Best of luck

Harold
PS Lee, thanks for the response!

21

Face and Body Scanning / Re: Scanning people: Tips needed

« on: April 25, 2012, 06:18:54 AM »

Lee,

I just found your own website and, after reading the most recent posts, I believe I could predict your answer.
It's amazing how many more polygons the agisoft program generates, and how greater the resolution it produces.
Great work!

Harold

22

Face and Body Scanning / Re: Scanning people: Tips needed

« on: April 23, 2012, 10:34:21 PM »

Hey Lee,

I hope this isn't off topic, and if it is, I apologize in advance.

I remember your excellent work on another forum related to scanning human subjects.  The software relied on stereo pairs and projecting a noise pattern. (I won't mention it here).  Would you please give me an idea why you've changed to agisoft photoscan? 

Harold