Compensation circuit for the correction of image defects of a television image
AssigneeGretag Aktiengesellschaft
InventorPhilippe Roth
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Abstract
In a compensation circuit for the correction of image defects of an image projection system according to the control layer principle, in particular of an eidophor projector, a compensation signal is produced from signals associated with three adjacent lines, using an adder followed by a coefficient multiplier in order to produce a compensation signal. The amplitude of the compensation signal assumes a maximum value for low values of an intermediate image point in a single column image matrix of a video signal and a minimum value for high levels of the intermediate image point.
Claims10
A compensation circuit for correcting image defects of a television image, comprising:
- means for receiving a video signal;
- two line memories for storing lines of the video signal;
- at least one coefficient multiplier for multiplying values of the video signal lines;
- a first adder for generating a compensation signal of three consecutive lines of the video signal;
- a second adder for adding the compensation signal to an intermediate line of said three consecutive lines of the video signal;
- and
- at least one electronic circuit interconnecting said first adder with said second adder, and for further processing said compensation signal to take into account a brightness level of a prevailing image point in the intermediate line of the video signal and/or a difference between the brightness level of the prevailing image point and of vertically adjacent image points of the video signal.
Dependencies are inferred from the claim text.