Geometric camera calibration

Imagine you have a camera, and you want to use it to take pictures or videos of things in the world. The camera is like a person's eye – it can see things, but it needs to be 'calibrated' so it can accurately see those things. This process of calibration is called geometric camera calibration.

During calibration, we help the camera 'learn' about the world around it. We do this by taking pictures of an object with known properties, such as a checkerboard, a known shape or object, or a measuring tool. We then use these pictures to create a mathematical model of how the camera sees the world.

With this model, we can adjust the camera's settings like focal length, distortion, and position. All of these settings can change how the camera sees and records images or video.

By calibrating the camera, we can make sure the images or video we take are accurate and have the right size, shape, and location. This is important when we need to measure distances or angles, or when we want to get a realistic view of a scene.

Think of it like putting on glasses – when we get glasses, we see the world more clearly, and everything looks better. When we calibrate a camera, it's like putting glasses on the camera, so it can 'see' the world more clearly too.