I am experimenting with an app to calculate the length of a person with the camera of my phone. I put my phone on the ground against the wall and make a picture. This situation is shown in the image below (side view):
The following variables are known:
- The pitch of the phone p (20°)
- The vertical field of view of the camera (60°)
- The distance of the person to the wall (2 meters)
Now I want to calculate the length of l.
The picture taken by the camera looks like this (front view):
From this picture I can read the following variables:
- The height of the image is 1000 pixels
- The height of the person on the image is 750 pixels
Although, it must be noted that the proportions on the image will not reflect the real person due to the perspective of the camera as can be seen here (side view):
I'm not sure if all of this information is relevant or if there is anything missing. In that case, please let me know.
I'm currently stuck with this problem and hope that someone can guide me in the right direction. Any help would be greatly appreciated!