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Author Topic: Calibration parameters for Powershot G16  (Read 1339 times)

RGBttt

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Calibration parameters for Powershot G16
« on: January 31, 2021, 07:10:21 PM »
Hi all,

I am trying to work with a video that was shot by a Canon Powershot G16. By taking ~3 frames per second, I am able to build a decent looking model from this video, showing the bumps in the terrain properly. I want to make sure calibration parameters are included as well, but as soon as I enter what I think are the right parameters, the model becomes 2D planar.

According to the specs, the pixel size of this camera is 7.44 mm x 5.58 mm.
It's a compact camera, which has 5x optical zoom focal length from 6.1-30.5mm. The 35mm equivalent of this range is 28–140mm.

According to the metadata of my video, the focal length I shot was 6.1mm.

Both 7.44 mm x 5.58 mm & 6.1mm and 7.44 mm x 5.58 mm & 28 mm result in a planar model. In both cases, I entered the "camera type" to be Frame.

Can someone advice what the right combination of parameters should be?

Many thanks.




Paulo

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Re: Calibration parameters for Powershot G16
« Reply #1 on: January 31, 2021, 07:44:30 PM »
Hi RGBttt,

I think you are confusing image or Sensor size with pixel size. Image size for this camera is 7.44 mm x 5.58 mm. Now pixel size would be Image size divided by image resolution.

So if you were taking stills at max resolution, that would be 4000 x 3000, so pixel size would be:

(7.44 mm / 4000, 5.58 mm / 3000) = (0.00186 mm, 0.00186 mm).

Now for video, I do not know exacly what would be Image resolution.

And focal should be 6.1 mm.
« Last Edit: January 31, 2021, 08:05:36 PM by Paulo »
Best Regards,

Paul Pelletier

RGBttt

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Re: Calibration parameters for Powershot G16
« Reply #2 on: January 31, 2021, 08:14:09 PM »
Thank you very much, Paul. The models are 3D again :-)