video sampleWhen the camera isn’t exactly orthogonal to the area being shot, a perspective error is introduced – thus a rectangular area becomes a trapezium in the video frame. In many situations this hardly is a problem, but sometimes it is. The keystone correction feature allows to rectify this bias.
This feature is very handy in situations where the scene framed by the camera is an interactive projection, like in the “Loghi in Fuga” videoinstallation.
Without keystone correction, the setup of this kind of videoinstallation would require a long and tedious work of camera positioning and pointing.
The keystone correction mask is a quadrilateral graphical artefact. The squared vertexes (above) can be dragged around to match the object to be keystone-corrected - the projection frame in the “Loghi in Fuga” example.
Above left, a mask properly defined to keystone-correct a strongly perspective affected video frame. Above right, the corrected image.
Mocolo Keystone correction is implemented in a very general way, and allows also to crop, rotate and reflect (at the same time) the video stream in realtime.
Above, for instance, a mask defined to both kestone-correct and to rotate the analyzed frame.
And again, a mask to keystone-correct and reflect the analyzed frame.