CODEWITHSUNDEEP
computer-visioncalibration
kenneth
kenneth

Reputation: 167

Use calibration matrix to know CCD sensor size

How can we know the camera sensor size from the calibration matrix?

I already have the calibration matrix. But the focal length is in pixels form.

Upvotes: 4

Views: 4631

Answers (2)

Francesco Callari
Francesco Callari

Reputation: 11785

As Zaphod says, you can get a decent approximation combining the calibration matrix with a known focal length for the lens in mm.

A more precise method: open the box, read the serial type number of the CCD, look it up on the interwebs. There are only a handful of CCD manufacturers, and they all publish their spec sheets on the web. Here is an example.

Upvotes: 1

Zaphod
Zaphod

Reputation: 1927

The "focal length" in the calibration matrix is not actually expressed in pixels. It is in fact a ratio that relates the sensor size in the real world to the size of a pixel in the image. It relates the focal length of the lens to distances in the image using a scaling factor in each dimension. More details in this article.

Upvotes: 4

Related Questions