Hi,
I use custom lenses and get quite big distortion. How can I find proper values of CLEYE_LENSCORRECTION1, CLEYE_LENSCORRECTION2 and CLEYE_LENSCORRECTION3 to correct it?

Thanks in advance

Currently this is a custom process, you may want to grab CCV 1.3 (ccv.nuigroup.com) which allows you to use sliders to fine tune your camera distortion. (Load CCV > Click Camera Settings on Right) It is in our roadmap however to automate this process.

Are those parameters same as or related to those in OpenCV (k1, k2 and k3 from CvCalbobrateCmera2 method)?

Yes they are radial distortion coefficients based on the same barrel distortion formula used on OpenCV.
The mapping is as following:

x’ = x * (1 + k1*r^2 + k2*r^4 + k3*r^6)
y’ = y * (1 + k1*r^2 + k2*r^4 + k3*r^6)

If anyone has same problem:

After some testing I figured out that openCV may be used for getting those parameters; you need distortion_coeffs matrix, that you get from CvCallibrateCamera2(). Parameters are:
CLEYE_LENSCORRECTION1 = 255 * distortion_coeffs[0,0]
CLEYE_LENSCORRECTION2 = 255 * distortion_coeffs[1,0]
CLEYE_LENSCORRECTION3 = 255 * distortion_coeffs[4,0]

The factor (255) is my guess; I’m pretty sure it’s correct value.

mruce,

Thanks for posting this information, I’m sure it will be useful to a lot of people interested in lens calibration.