Dear DAVID Community,

As you are probably aware, the entire DAVID company, team and product range has been integrated into HP Inc.
This forum is now read-only. Relevant content has been migrated to HP and merged into HP's Support Forums on November 1, 2016.

To start new discussions for 3D Scanning, please register and post your new topic at the HP Support Forums

how to scan black hair by structured light?

Problems, solutions and discussion about scanning with a video projector and stripe patterns.

how to scan black hair by structured light?

Postby meng » Thu Aug 13, 2009 9:24 pm

Currently, I am working on a realtime 3D structured light system (see http://vis.uky.edu/~realtime3d/ ). The frame rate achieves 120 fps for acquisition and data processing. Everything works fine except that I want to scan black hair... Structured light does not work well on black object. So, does anyone have any idea how to overcome this problem? Thanks!
meng
 
Posts: 5
Joined: Thu Aug 13, 2009 8:19 pm

Re: how to scan black hair by structured light?

Postby MagWeb » Thu Aug 13, 2009 10:10 pm

Hi,

forgive that old joke:
Wait till the hair gets grey..... :lol: :mrgreen: :lol:

Maybe some kick - never tried - only a thought:

Black means: not reflecting wavelengths visible to the human eye.... maybe another instrument may catch reflections from such a surface?...maybe a projector could send such wavelengths?

Gunter
MagWeb
Moderator
 
Posts: 2499
Joined: Wed Jul 18, 2007 8:48 pm

Re: how to scan black hair by structured light?

Postby meng » Sat Aug 15, 2009 12:46 am

Yes, pure black will fail. But I am think, since some light is still getting from the hair, whether increasing the exposure time of camera will be helpful. Did anyone try it?
meng
 
Posts: 5
Joined: Thu Aug 13, 2009 8:19 pm

Re: how to scan black hair by structured light?

Postby KopkoH » Sun Aug 16, 2009 4:34 am

Do you have plan to published your software on site? It would be nice to look :-)
KopkoH
 
Posts: 39
Joined: Sun Feb 10, 2008 5:55 am

Re: how to scan black hair by structured light?

Postby jantje » Sun Aug 16, 2009 1:57 pm

Meng
I did some tests with my RIG to do some face scanning. As I have really dark black hair there is simply no laser refection (I knew that from previous scans). Moreover you have the problem of the thickness of hair. Simply put: thin curly hair is to unstructured to be scanned this way.
This is why I did 2 things to get my hair scanned.
1) Use wax to make my hair look solid. (ordinary wax to change your hair style)
2) Use a hair spray on top of the wax to make my hair grey (I used grey as I had it lying around.)

The spray is a spray used in theater to dye hair very temporary. Washing and it is gone. if you look for "theater color spray" in google you'll find plenty of places to buy it from.

Hope this helps you out.
Jan
User avatar
jantje
 
Posts: 107
Joined: Tue Mar 03, 2009 12:08 am
Location: Belgium

Re: how to scan black hair by structured light?

Postby meng » Mon Aug 17, 2009 12:55 am

I am a PhD student in 3D imaging lab. Although the system is mainly made by another PhD student and me, whether the code will be published is decided by my supervisor :) . Maybe it will.

However, the high speed of the system is due to the fact that the new pattern strategies and data processing methods are employed. We will have papers published about the techniques soon.

KopkoH wrote:Do you have plan to published your software on site? It would be nice to look :-)
Last edited by meng on Mon Aug 17, 2009 12:57 am, edited 1 time in total.
meng
 
Posts: 5
Joined: Thu Aug 13, 2009 8:19 pm

Re: how to scan black hair by structured light?

Postby meng » Mon Aug 17, 2009 12:56 am

Thanks~! I will try that. Hope it works in realtime system~ :)


jantje wrote:Meng
I did some tests with my RIG to do some face scanning. As I have really dark black hair there is simply no laser refection (I knew that from previous scans). Moreover you have the problem of the thickness of hair. Simply put: thin curly hair is to unstructured to be scanned this way.
This is why I did 2 things to get my hair scanned.
1) Use wax to make my hair look solid. (ordinary wax to change your hair style)
2) Use a hair spray on top of the wax to make my hair grey (I used grey as I had it lying around.)

The spray is a spray used in theater to dye hair very temporary. Washing and it is gone. if you look for "theater color spray" in google you'll find plenty of places to buy it from.

Hope this helps you out.
Jan
meng
 
Posts: 5
Joined: Thu Aug 13, 2009 8:19 pm

Re: 12 structured light files ?

Postby Angus » Wed Aug 19, 2009 9:12 am

Hi,

I'm a newbie who can't find the 12 structured light files mentioned, can anyone please help me? I don't see an EXPERIMENTAL folder with structured light files on my new [color=#80FF00]David USB. The link David_2_4_1_CLA.zip which used to lead to the structured light files, doesn't. Sorry to butt in here but it was the only active thread that mentioned structured light.

Thanks,
AngusJohnMcLachlan@yahoo.com
Angus
 
Posts: 1
Joined: Mon Jul 20, 2009 10:05 am

Re: how to scan black hair by structured light?

Postby MagWeb » Wed Aug 19, 2009 10:40 am

Hi,

You´ve to update your program to the current version.

To do this on the USB edition:


From our WIKI:
On your DAVID USB Flash Drive, you will find a folder “DAVID”. It contains all necessary files. If you want, you can make a security copy of this folder, e.g. on your hard disk.
Download the latest DAVID version (.zip file) from here.
Extract all files from the .zip file to the “DAVID” folder on your Flash Drive. This will overwrite most of the old files. Some old files (e.g. license.dat) will not be overwritten; they must persist where they are!
That's it. Start DAVID from your Flash Drive as usual


You may find some other basic things there too.

Gunter.

BTW:
In order to keep a forum as clean as possible, it would be of some help to post questions only once. We´ll find it and answer it, if we can, as soon as possible. - Thanks!
So I deleted your other post of the same content.
MagWeb
Moderator
 
Posts: 2499
Joined: Wed Jul 18, 2007 8:48 pm


Return to Structured Light Scanning

Who is online

Users browsing this forum: No registered users and 2 guests

cron