Perspective distortion error
Definition
The apparent change in size of objects at different distances from the camera due to projective geometry. A person closer to the camera appears larger in the frame than a person of identical height further away. Uncorrected perspective differences between subject and reference are the most common source of height estimation error.
Related terms
- Ground-plane calibration
- A physical survey of the scene after the event, measuring reference points on the floor relative to the camera position, allowing the...
- Pixel height ratio
- The number of pixels occupied by a vertical extent (person, door, markings) in the image. Ratios between subject and reference pixel heights...
- Reference-object method
- Height estimation by measuring the pixel heights of both the subject and a reference object of known stature in the same frame,...
- Stature estimation uncertainty
- The combined error from pixel localisation, reference height knowledge, positional correction accuracy, and camera model assumptions, expressed as a confidence interval at...
- Vanishing-point method
- Using the vertical vanishing point and two horizontal vanishing points to compute the camera's effective viewing geometry, then projecting the person's image...
Explained in
- Height Estimation from CCTV FootageThe apparent change in size of objects at different distances from the camera due to projective geometry. A person closer to the camera appears larger in the f...