No depth in realtime Scan...

[Simon]

Hi

I think it's amazing that you are all doing such great work.

I've been trying to get my head around the whole concept for about a
month and have finally gotten the gear together to start doing my own
tests - hoping to use it in an upcoming project. I come from a
photography background so I have a little trouble understanding the
advanced jargon and coding chat but I'm getting there.

So far I have the single scan threephase set up down no problem. Using
a mac, slide showing the pattern images one by one through the
projector- shooting one still of each. I've tried a few different
camera types and everything works fine using the basic threephase app
and again using the threephase.pde through Processing having
downloaded and installed the libraries. I can see some colors changing
between frames but it still generates a 3D scan and I actually don't
mind the color. Example here under (A) http://structuredtrouble.tumblr.com/
(Noisy example sorry).


The big problem I'm having is with the realtime 3D scanning.

I've downloaded - StructuredLIght OSX v0.3 COMPLETE

I start Capture - go Full Screen - Enable camera (PS3 Eye shows up in
the 3 small windows) - hit Tab and record to the Capture Folder.

I then bring the capture folder jpegs into Data then Input folders
under 'Test' for example. Then quit Capture and open Decode.

I select 'Test' in the Input window. Here lies the problem - the
project remains flat. Obviously when playing around with range/skew/
scale it adjusts the image but it doesn't get the 3D result that I see
in Kyle McDonalds (awesome work by the way) vimeos or in fact anywhere
near. Here are three jpegs that I grabbed from the middle of the
capture in case this helps… Contrast is a little high.
Under (B) http://structuredtrouble.tumblr.com/


I've tried every combination I can think of. I think it may be my
projector - BenQ w600+ (http://www.benq.us/products/product_detail.cfm?
product=1699&pltag=7&ptag=88). When I mirror the display from my
laptop Im setting the display in the w600+ window to 1024x768 then
doing the same to my Color LCD just for good measure.

When I go into the menu of the projector itself I can't seem to change
the resolution manually - it does however say in the system status
that the resolution is 1920x1080 - does this matter even though the
input (through HDMI) from the computer is set to 1024x768 ??

I didn't think it would seeing as the projector worked fine for the
threephase single scan. Then if I load in just three jpegs that worked
in the threephase single scan into the Input folder then in Decode the
image comes up fine with depth etc though obviously it can't be
played.
See here under C http://structuredtrouble.tumblr.com/


I'm pretty baffled otherwise. I've spent three days trying different
variations - all different levels of brightness and contrast.
Different camera positions. Diefferent levels of ambient light.
Different objects, different backgrounds, different resolutions from
the laptop, all the different options withing Capture and Decode
(frame rates, pattern rates, reverse, vertical etc). I thought if it
could be a color thing so I converted all the jpegs to black and
white. I also tried using a G10. I tried the settings I saw in the
'making of' the MMX video.

Does anybody have any ideas? There's nothing that I'm missing in the
set up is there? As in libraries or anything?

Thanks very much and keep up the good work - very, very impressed.

Cheers
Simon

[Kyle McDonald]

hi simon,

sorry for the delay in approving your message, i've been busy with a couple other things (as indicated in another thread...).

looking at your photos on the tumblr, i can immediately say that it's because your project is DLP.

when you take single images as in (A), this isn't a problem because the exposure time on your camera takes longer than a single frame (probably more like 1/30 or 1/20 of a second).

on the other hand in (B) you're using a camera that has a faster exposure time, and a faster framerate.

one possibility is to try dropping the framerate on your camera to 30 fps, and locking the exposure to either exactly 1/60th of a second or 1/30th of a second. you'll know it's right when you stop seeing the colors.

secondly, as you point out, the contrast is really high. dropping the contrast on the project and camera should help a lot.

finally, for "more depth" try "more separation" (between the camera and projector). the more extreme the line curves, the more nuanced the depth image.

hope this helps!

kyle

[Simon Cave]

Hey Kyle 

Thanks so much for getting back to me. Finally got my hands on an LCD projector and of course it worked fine after that. Next step is to keep playing around with the set-up as well as the settings/frame rate etc to get it a little more stable. Playing around with the Canon 5D, 60D, G10 and ps3 eye. Will let you know how it goes. Once i'm a little more comfortable I'll run a test through a friends Red camera at 60fps... Will keep you updated. 

Thanks again Kyle!

Simon

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Site - www.simoncave.com

Blog - www.august-10.com