Is it possible to hack camera calibration without having access to the camera?

1. How many images needed for camera calibration?
2. Is camera calibration necessary?
3. What does camera calibration do?

How many images needed for camera calibration?

Open the camera(you can use OpenCV codes or just a standard camera app.) and take at least 20 images. They should be in different angles and distances because the calibration code needs various points with different perspectives.

Is camera calibration necessary?

The camera calibration aims to determine the geometric parameters of the image formation process [1]. This is a crucial step in many computer vision applications especially when metric information about the scene is required.

What does camera calibration do?

Camera calibration is the process of finding the true parameters of the camera that took your photographs. Some of these parameters are focal length, format size, principal point, and lens distortion.