System and method for focusing a moving image camera
A focus setting display unit for a moving image camera comprises a data input that is configured to receive a focus setting that represents an instantaneous focal distance of an objective of the moving image camera as well as to receive distance values that represent the distances of a plurality of scene points in the field of view of the objective from the moving image camera. The focus setting display unit further comprises a display device and an evaluation and control device that is configured to control the display device to display a graphical representation of the focus setting and a graphical representation of a frequency distribution of the distance values in a spatial relationship to one another that reflects the spatial relationship of the instantaneous focal distance of the objective to the distances of the plurality of scene points.
1. A focus setting display unit ( 21 ) for a moving image camera ( 11 ), comprising
a data input ( 23 ) for receiving a focus setting that represents an instantaneous focal distance of an objective ( 15 ) of the moving image camera ( 11 ) and for receiving distance values that represent the distances of a plurality of scene points in a field of view ( 13 ) of the objective ( 15 ) from the moving image camera ( 11 );
a display device ( 27 ) configured to display a graphical representation of the focus setting ( 29 ) and a graphical representation of a frequency distribution of the distance values in a spatial relationship to one another that reflects the spatial relationship of the instantaneous focal distance of the objective ( 15 ) to the distances of the plurality of scene points.
2. The focus setting display unit in accordance with claim 1 , wherein the display device ( 27 ) is configured to depict the focus setting and the frequency distribution ( 25 ) arranged along a common axis (U) for the display of the graphical representation of the focus setting ( 20 ) and of the graphical representation of the frequency distribution ( 25 ) of the distance values.
3. The focus setting display unit in accordance with claim 1 , wherein the frequency distribution ( 25 ) of the distance values is a uniform frequency distribution in that each distance zone of a series of consecutive distance zones has the number of all of the distance values falling in this distance zone associated with it as a frequency.
4. The focus setting display unit in accordance with claim 1 , wherein the frequency distribution ( 25 ) of the distance values is a frequency distribution specific to a field of view portion in that the field of view ( 13 ) of the objective ( 15 ) is divided into portions and the number of those distance values falling in this distance zone is associated as a frequency with each combination of one of the portions with a distance zone of a series of consecutive distance zones, said distance values representing the distance of a scene point disposed in the respective portion from the moving image camera ( 11 ).
5. The focus setting display unit in accordance with claim 1 , wherein the display device ( 27 ) is configured to display a graphical representation of the frequency distribution ( 25 ) of the distance values that is restricted to at least one of: a predefinable distance zone and an adaptive distance zone.
6. The focus setting display unit in accordance with claim 5 ,
wherein the adaptive distance zone corresponds to the zone of a peak of the frequency distribution ( 25 ) that of all the peaks of the frequency distribution ( 25 ) corresponds to the smallest distance from the moving image camera ( 11 ).
7. The focus setting display unit in accordance with claim 1 , wherein the display device ( 27 ) is configured to display a graphical representation of the frequency distribution ( 25 ) of the distance values that comprises a separate marking of maxima of the frequency distribution ( 25 ) by means of graphical markers.
8. The focus setting display unit in accordance with claim 1 , further comprising:
a control signal output ( 35 ) for outputting control signals to adjust the focal distance of the objective ( 15 ).
9. The focus setting display unit in accordance with claim 8 , further comprising:
an operating element ( 31 ),
wherein control signals are output to adjust the focal distance of the objective ( 15 ) at the control signal output ( 35 ) in dependence on actuations of the operating element ( 33 ).
10. The focus setting display unit in accordance with claim 8 , wherein control signals are output to adjust the focal distance of the objective ( 15 ) at the control signal output ( 35 ) in dependence on changes of the frequency distribution ( 25 ) of the distance values.
11. The focus setting display unit in accordance with claim 10 , wherein the control signals are output such that the focal distance of the objective ( 15 ) is regulated in accordance with a desired value for the focal distance defined by a characteristic zone of the frequency distribution ( 25 ).
12. The focus setting display unit in accordance with claim 1 ,
wherein the display device ( 27 ) comprises a touch-sensitive screen that is configured to display the graphical representation of the focus setting ( 29 ) and the graphical representation of the frequency distribution ( 25 ) of the distance values and to detect touch inputs.
13. A focus setting system for a moving image camera, comprising
a focus setting display unit ( 21 ) comprising:
a data input ( 23 ) for receiving a focus setting that represents an instantaneous focal distance of an objective ( 15 ) of the moving image camera ( 11 ) and for receiving distance values that represent the distances of a plurality of scene points in a field of view ( 13 ) of the objective ( 15 ) from the moving image camera ( 11 );
a display device ( 27 ) configured to display a graphical representation of the focus setting ( 29 ) and a graphical representation of a frequency distribution of the distance values in a spatial relationship to one another that reflects the spatial relationship of the instantaneous focal distance of the objective ( 15 ) to the distances of the plurality of scene points; and
a distance sensor ( 19 ) for measuring the distances of the plurality of scene points from the moving image camera ( 11 ) and for outputting distance values that represent the measured distances to the data input ( 23 ) of the focus setting display unit ( 21 ).
14. The focus setting system in accordance with claim 13 ,
further comprising:
an objective drive apparatus ( 37 ) that is configured to receive control signals output at a control signal output ( 35 ) of the focus setting display unit ( 21 ) and to adjust the focal distance of the objective ( 15 ) in dependence on the received control signals.
15. A method of simplifying the focusing of a moving image camera ( 11 ), said method comprising the following steps:
detecting a focus setting that represents an instantaneous focal distance of an objective ( 15 ) of the moving image camera ( 11 );
measuring the distances of a plurality of scene points in a field of view ( 13 ) of the objective ( 15 ) from the moving image camera ( 11 ) by means of a distance sensor ( 19 );
determining a frequency distribution of distance values that represent the measured distances; and
displaying a graphical representation of the focus setting ( 29 ) and a graphical representation of the frequency distribution ( 25 ) of the distance values on a display device ( 27 ) in a spatial relationship to one another that reflects the spatial relationship of the instantaneous focal distance of the objective ( 15 ) to the distances of the plurality of scene points.
16. The method in accordance with claim 15 , additionally comprising the following steps:
identifying a characteristic zone of the frequency distribution ( 25 ) as representative for an object (A-F) to be focused;
and adjusting the focal distance of the objective ( 15 ) until the graphical representation of the focus setting ( 29 ) and the graphical representation of the frequency distribution ( 25 ) of the distance values on the display device ( 27 ) are displayed in a spatial relationship to one another that corresponds to a focusing of the characteristic zone.
17. The method in accordance with claim 15 ,
wherein the step of displaying the graphical representation of the focus setting ( 25 ) and the graphical representation of the frequency distribution ( 25 ) of the distance values on the display device ( 27 ) comprises depicting the focus setting ( 29 ) and the frequency distribution ( 25 ) arranged along a common axis (U).