According to OpenCV documentation:
https://docs.opencv.org/2.4/modules/calib3d/doc/camera_calibration_and_3d_reconstruction.html
“If, for example, a camera has been calibrated on images of 320 x 240 resolution, absolutely the same distortion coefficients can be used for 640 x 480 images from the same camera while , , , and need to be scaled appropriately.”
I am using a RealSense depth camera and I list its focal lengths for different resolutions. However, I found the focal length does not scale accordingly. The focal length fx (along x direction) is 608 for width 640 and the fx is 913 for width 1280. The fx does not double as the resolution changes from 640 to 1280
Thank you!
Yixun