Understanding relationship between image resolution and "zoom" capability
New to CV so sorry if this question lacks proper terminology or is completely nonsensical. :)
The goal is to track a specific player during a basketball game and produce a video that follows him around during the game. More specifically, every frame of the video will be centered around him instead of the ball.
One CV expert suggested the following:
The general approach is to have a very high definition video feed with a still camera and zoom into and around the still image and create the illusion that you are zooming/panning a regular camera.
Could someone elaborate on how "high definition" this camera needs to be? 4K? And more abstractly, is there a relationship between the resolution of the video feed and how much "zoom" capability this yields? For instance, if you have a 4K feed, could you zoom around a basketball court of 90 feet? Could you zoom around a football field of 100 yards?
His suggestion is simply bullshit ... software PTZ camera's, only work for fairly stable scenes. Instead, get yourself a PTZ setup, apply a tracker combined with a detector, in your case if you can select the player beforehand, the OpenTLD tracker will be exactly what you need! Then based on the movement of your tracker in the image, adjust your PTZ setup.
@StevenPuttemans could you elaborate please? Why is his answer not helpful -- isn't a basketball game considered a stable scene? What do you mean by "get yourself a PTZ setup and apply a tracker combined with a detector"? Are you referring to hardware or software? Sorry for not understanding, but thanks for your patience!
The downside of a system that has a fixed camera and does a software PTZ (which is pan tilt zoom) camera, by moving around in the image, is that the original camera has to have a huge resolution in order to maintain some decent end video. In sport scenes, to capture a player, camera's are mostly placed up high, somewhere above the crowd. If you compare a single player to the overall resolution, then be prepared to pay alot for that high resolution camera. A lower resolution camera might not be able to capture the whole field but it can increase resolution in a specific area. By detection I mean you need to detect the player somehow, either automatic or either manually, then apply a feature tracker onto them to follow them around in the image. Start googling for CV tracking.
@StevenPuttemans thanks for the clarification. Yes, this wouldn't be used for professional sporting events so the camera will be perched right next to the court. If I understand you, the downside to the lower resolution camera means you must do real-time player tracking on the camera device (let's ignore the manual option where a human pans the camera to follow the player) -- wouldn't that also increase the cost? The question then becomes: is it cheaper to do on-device tracking or to increase the camera resolution?