How to calculate the coefficient k for the lens in the picture below?
https://i.stack.imgur.com/QDhW8.png
The lens needs to be described by a simplified Quartic model (the fourth-order coefficient is equal to zero):
https://i.stack.imgur.com/A3myz.png
Notes:
Image size is 1281 x 641 pixels. So, the central pixel of the image has 640 pixels on its left and right side, and 360 pixels on its bottom and top. Pixels are considered to be square and there are 1000 pixels per unit length, which means that the distances of the pixels from the projection of the center of the lens are within the following limits:
https://i.stack.imgur.com/n8T13.png
It is considered that the center of the network is ideally aligned with the center of the lens, ie the center of the lens (also the center of radial distortion) ideally coincides with the central pixel of the image. There is also an image of a square grid made with an ideal lens without radial distortion:
