Method for controlling the focussing device for an objective of a TV camera or the like

摘要

This camera is used for generating a sequence of frames. The control is effected in dependence on the picture contents of the frames, the frames being subdivided into part-frames, attention fields being determined, edge operations being carried out and histograms being determined. If the maximum of a histogram is located at wide base widths, the focussing device is switched on for adjusting the sharpness of the objective, the consequence being that the maxima of the histograms move from frame to frame, the direction of movement of the focussing device being changed when a maximum moves in the direction of wide base widths in a next frame. The maxima of the histograms in which changes in direction have been carried out are marked as turning points, with the consequence that the point of maximum sharpness is located between two turning points. If a maximum is located at "zero" or "one" between two turning points, this adjustment of the focussing device is determined as the setting of maximum sharpness.