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Author Topic: Generate allready scale model  (Read 3621 times)

Danic

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Generate allready scale model
« on: November 24, 2014, 03:15:53 PM »
It's possible with a good camera calibration, generate allready scale model?
PS
I can't use GCP or marker...the proccesing must be more easy possible.

Tanks

Kiesel

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Re: Generate allready scale model
« Reply #1 on: November 25, 2014, 05:51:59 PM »
This has nothing to do with camera calibration at all! You can fill your photograph with a coin or with the moon ;), it has only to do with image scale.
So you need something of a known length in some of your photographs and then you can use it to scale your model (scale bar function in PhotoScan Pro or with a 3rd party software like the free Meshlab or CloudCompare for PhotoScan Standard).

Karsten
« Last Edit: January 10, 2015, 11:13:22 AM by Kiesel »

mr_cg

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Camera calibration method to get correct scale of model ???
« Reply #2 on: January 08, 2015, 11:46:30 PM »
Is it possible to modify the camera calibration parameters in order to have correct scale in photoscan (standard version)? I really miss the scale calibration in the standard version. Any other solution, welcome.

Kiesel

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Re: Camera calibration method to get correct scale of model ???
« Reply #3 on: January 09, 2015, 01:07:55 PM »
Hi mr_cg,

Quote
Is it possible to modify the camera calibration parameters in order to have correct scale in photoscan (standard version)?

No, because it is a question of varying distances from cameras to your object of interest => different image scale.

How you can do it with Meshlab look here:

http://www.agisoft.com/forum/index.php?topic=2447.msg12997#msg12997

Another option with higher accuracy is SFM_georef (but I don't know if it is compatible with the newer version 1.1 of PhotoScan):

http://www.lancaster.ac.uk/staff/jamesm/software/sfm_georef.htm

Karsten
« Last Edit: January 10, 2015, 11:14:12 AM by Kiesel »