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SLS Image Grabber - What am I doing wrong?

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

SLS Image Grabber - What am I doing wrong?

Postby OvaR8ed » Sun Feb 21, 2016 2:34 pm

I can get live scanning to work perfectly, but I recently got a DSLR Camera and a portable projector so I want to use the Image grabber to make the setup more mobile.

So I saved the Patterns for a default scan, loaded them on the projector, setup the projector and camera at approximately 30 degrees and took a pic of each pattern using a remote.

I set the software to Image Grabber

I browse to the images and select cam_calib and the image files.
There is a copy of the images in the following zip file: (10MB)

The images load and the sequence starts playing by itself.
I go to Calibrate (note that both is selected by default) and then it calibrates successful.

I did notice after the calibration that the dropdown changed to Horizontal by itself, should this happen...?

Without changing any settings I hit Scan Background

There are no errors, but everything comes out in one weird flat plane...?

I thought this had something to do with the fact that I loaded Both Horizontal and Vertical Lined Images, but the Calibration changed to Horizontal automatically. I changed the Dropdown back to Both and scanned the background again, this time it looked even worse!

Then I changed back to Horizontal, but this time I only browsed and selected the images with Vertical Lines on them:

From far it looked like success, but when I zoomed there was a weird stepped effect going on in the scan of the background

I really don't know what to do next... Can anyone help?
Posts: 8
Joined: Fri Feb 24, 2012 2:55 pm

Re: SLS Image Grabber - What am I doing wrong?

Postby Curiousjeff » Sun Feb 21, 2016 6:17 pm

If you look at your images in a regular image viewer in color, you can see that you have a frequency problems. Simply look at your thumbnails. It's a rainbow.

You must adjust you shutter speed to 1/60 of a second.

I can't guarantee that that is the cause of the problem, but I would certainly try to remove those color differences.

See also this link (including a video)

I find it very risky to try to scan without a computer, with only a projector and a camera. If something went wrong and you can't calibrate once back at the office, you lost all your work.

Maybe the David team will want to make a mobile App only to check the calibration ? :D
Then yes, you could safely be mobile
Panasonic GH4 4K with lens 12-35, Inogeni 4K to USB3 hdmi capture device, projectors: Acer K135/Acer K11/NEC V260X, Canon 60D, macro 60 mm, MagicLantern
Posts: 230
Joined: Fri Feb 27, 2015 2:17 pm
Location: Geneva, Swizerland

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