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Messages - Tyler J

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Face and Body Scanning / Re: First full head scan
« on: May 20, 2014, 04:41:53 PM »

Face and Body Scanning / Re: Mounting cameras to light stands
« on: May 14, 2014, 02:44:55 PM »
Bike Handlebar Bracket Mount Holder 2.49$

I use several of them, they are very good.

From : TUTORIAL - Request

Quote from: Andrew
I personally don't import camera positions, it's just too easy for fixed cameras (and their lenses) to get gradually off their previously calibrated positions. Also, if you are using multicam rig with good lighting and some of your cams fail to align, it _usually_ means your photos are not sharp enough, or your cams are spread out too far etc. In case of really pale skin/featureless subject, you can go to 'Tools/Export/Export_Cameras', save your 'sphere' camera setup and then load it ('Tools Import\Import_Cameras' when you switch to your 'face' setup.



recently I made a 3d face scanner based on 21 point and shoot cameras.
21 coolpix l27, this was a bad choice, I did not know that low end cameras
did not allow settings such as ISO or shutter speed to be set.
Canon camera would have allowed it through firmware hacking and unfortunatly
there is no community based around nikkon point and shoot camera firmware hacking.

I modified the cameras so they could be triggered and made my own power adapters.

That being said, I'm having good result using the "auto" mode force to macro
which in the end always uses the macro scene.
In this mode the white balance can be set, i've set it to "flash" as I'm using cool white lighting.
however shutter speed and ISO is choosen by the camera. I lowered the exposure to -0.7
and each camera takes a shot with a 1/25 shutter speed and and ISO value betwen 80 and 120.

lowering exposure to -2 ensure an ISO of 80 but the lighting required to get a good picture
will hurt the eyes of the subject (lighting is constant)

pictures are being taken in the dark, only the lighting of the scanner is present,
it's composed of 7 30cm cool white led strip with transparent paper to diffuse the light.
CRI seems to be good enought, however I can see reflection on the subjects (is this a problem?)

Here is the scanner, heigh can be set and distance from the head too.

Here is my problem, subject1 is "perfectly" modelized, I can only align half of the pictures
for subject 2 so I get half a face.

subject 1

subject 2

Why this difference? here is a link for the hi-res pictures of subject 2 :
dropbox link
As you can see 19 of them are sharp, 2 of them are not focused on the face (one is focused on it's shirt, one on it's hairs)
removing the 2 bad pictures does the same thing, only half of the face is aligned.

what do you think about the orientation?
Vertical may be a bad solution, at first I tought that by maximizing the
face area in the pictures would generate more data.

But in the end only 1 third of the face is in focus.

by putting them horizontally I get only a piece of the face but it's all in focus.

Any idea why?


Ps : if someone here has a service manual please PM me :D I'd love to make a board capable of intercepting communication from the microcontroller in order to set ISO and shutter speed.

Face and Body Scanning / Re: Help ! can't create complete mesh.
« on: May 13, 2014, 02:46:56 PM »
What camera are you using (just out of curiosity)

Face and Body Scanning / Re: LED arrays
« on: April 30, 2014, 05:57:20 PM »
I did not know that, up until now I always though that white light was white light.
Well you could buy a prism, buy 1 7$ led and look at the spectrum.

I ordered a 5" prism, I'm going to see if my spectrum is continuous or not.

Face and Body Scanning / Re: LED arrays
« on: April 30, 2014, 12:51:30 PM »
I need their battery compartment to be empty (because I'm using it to get the wire to go outside).
the problem is that those camera are powered with 3V and consume up to 3.3A.
with this current and this low tension, each centimeter of cable matter (0.12Ohms induce a tension drop of 0.4V)

The solution I found was to use 0.75mm copper wire of 2.4 meter and a 3.3V tension source, cable of this lenght produce a drop of 0.3-0.35V :D

the ones i saw in ebay were about 5k, so i'd need a ton more if i use those ones
yeah but a 10K led cost 7$
With 2 of them you get 20k for 14$, your led is 14k for 50$

Face and Body Scanning / Re: LED arrays
« on: April 30, 2014, 11:46:49 AM »
I'm an electronic hobbist, one of my current project is a face scanner, however I just had 1500$ to spend so I build one compose a 21*Coolpix L27.
I cannot set parameters surch as ISO or aperture, etc but I'm getting EXCELLENT result.
I opened them and put some wire inside in order to be able to remote control them.

They are on a semi dodecagon at about 25cm of your face set to macro mode.
It is still a WIP, I'm having trouve with their alimentation, I made some kind of non-orthodox alimentation by using the power dissipated by the cable to lower the tension, however since some of them have slightly different electrical caracteristic they need specific length of cable.

For illumination I'm using led strip that are always powered on. their luminosity can be set using a PWM controller.
I made my own but if you buy some led strip on ebay, they, most of the time, give one free.

For your leds
you'll probably need something like this :
(using 100V capacitor of course)

Also, know that you can buy for a much smaller price high power led from ebay? they'll come from china and will need 30 days to get to you.
But from my experience those ebay LED are just as good as the one sold on regular website.

Face and Body Scanning / Re: LED arrays
« on: April 29, 2014, 02:23:49 PM »
I tried to use some with my face scanner, however they are way too bright.
You'll need to use a pwn controller to reduce their luminosity, because COB led behave weirdly when you reduce their current.
Plus you'll need a softbox.

Instead I use a regular white led strip, it's perfect.

General / Re: Is there a minimum resolution for photoscan?
« on: April 28, 2014, 01:28:13 PM »
may be it has to be taken in 2Mp and not reduced by a software

General / Is there a minimum resolution for photoscan?
« on: April 28, 2014, 11:02:07 AM »

I trie to do a webcam based scan it did not match anything.
After I downsized with paint a set of photos taken with regular cameras to
2Mpix and it did not match any of them.

At their standard size (18Mpix) there is no problem.

So I was wondering, is there a minimum resolution for photoscan?


General / Re: TUTORIAL - Request
« on: April 15, 2014, 11:35:44 PM »
I hear that it was possible to align photos then change them, but I can't find how to do it.

let me elaborate :
You have a setup of, say, 30 camera.
First you shoot a sphere with pattern on it.
then you shoot someone face.

In photoscan you align the pictures using the sphere, then you replace all photos by the one of the actual face.
Since the sphere was covered by a pattern the alignment is perfect.

Is this possible?

The canon 1100D is making pictures as good as the 600D?

Face and Body Scanning / Re: Face scanner - Prototype
« on: February 01, 2014, 01:24:44 PM »
Hello exhale

Im using this equivalent to photoshops high pass filter it works a little bit better from my tests.

I?ve applied "two step" smoothing filter, however it doesnt work as i?d like to, details arent preserved in the way i wanted. I might have a custom made bilateral denoise filter on the upcoming months... im not counting on it though. - Im very supprissed to not be able to find any software that have this kind of filter for 3d mesh... not even polyworks.

- The problem now with high pass filter is that my lights are moving relative to the subject so dark / light information is nowhere near accurate. I will change this on the following weeks.

Do you mean that you take each photo individually and apply a high pass filter with the same parameters for each pictures?

General / Rig calibration.
« on: January 30, 2014, 12:27:21 PM »

let's say I have a 30 sphere camera rig.
can I photograph a sphere like this to get good alignment.

[see attachment]

Then replace the detected camera one by one by pictures of the actual object I want to scan?
(Since the cameras are not moving)

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