Query regarding the focal length for undistorted images

[Joel-Rootgers]

Hello,

I assume the geolabel/cameras.txt has camera intrinsic parameters corresponding to the scale of the raw images. I was wondering how the focal length gets scaled down to match the width and height of the undistorted images (whose aspect ratio also varies from the raw images)

[csyhy1986]

I am also confused about the same thing. The files of cameras.txt records the camera parameters of the raw images, but the they did not indicate the corresponding images. The undistorted images have unknown camera parameters.

[lzx551402]

Hi, cameras.txt records the original camera parameters, including image size.
To obtain camera parameters, such as focal length of downscaled images, you may first compute the rescaling ratio in x and y, the apply the same ratio to adjust focal length.

[csyhy1986]

  issue in visualize.py  kpts0, kpts1 = read_kpt(kpt_path0), read_kpt(kpt_path0)

[ewrfcas]

Hi, cameras.txt records the original camera parameters, including image size. To obtain camera parameters, such as focal length of downscaled images, you may first compute the rescaling ratio in x and y, the apply the same ratio to adjust focal length.

However, the intrinsic matrix will also be influenced by undistortion. Thus we need more details about the new intrinsic for undistorted images.