比個example你地：
我個問題：
>2. Does that single image of something with known dimensions have to
>be the same resolution as the cine files we're trying to analyze?
In Field Engineer比我地既Answer:
No. I think as long as you input correct the dimensions between the
target points of the calibration image, the software adjusts. Perhaps
the folks at Image Systems can verify for us.
(都ok睇得明)
再黎多個係sweden 一個 expert既 Answer:
>>It depends on the camera. When calibrating the cameras in TEMA both external parameters (camera position and attitude) and internal parameters (focal length, principal point, lens distortion (optionally)) are required. The principal point is the 2D position on the camera sensor where the optical axis intersects the sensor.
For many applications a sufficient accuracy is achieved by manually entering the focal length, as specified from the manufacturer, have the principal point in the middle of the sensor, disregard lens distortion, and only calibrate for the cameras external parameters.
When changing resolution the principal point may or may not change depending on the camera. If all available resolutions are centered around the principal point, then you can calibrate with one resolution and test with another resolution. If not, then you need to calibrate and test with the same resolution.
(外星文
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