Pixel artifact/blemish filter for use in CCD video camera
First Claim
1. In a charge-coupled device video camera for producing a video image signal composed of a series of pulses, each representing a pixel, from which a video image may be developed, a pixel artifact filter for filtering pixel artifact pulses which differ in magnitude from next adjacent non-artifact pulses, said filter comprising:
- delay means for receiving the video image signal produced by the camera, and for delaying each video image signal pulse of the signal by a predetermined amount, andmeans for receiving each non-delayed video image signal pulse directly and unmodified from the camera, pairing each non-delayed pulse and most recently delayed pulse, and for passing either said each non-delayed pulse or said each delayed pulse, depending upon the relative magnitude of the pulses.
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Abstract
A pixel artifact/blemish filter for use in a CCD video camera which produces a video signal composed of a series of pulses, each representing a pixel, for developing a video image. The filter includes a delay line for receiving the video signal produced by the camera, and for delaying the video signal pulses by a time of approximately one pulse width duration. The filter also includes first and second signal transfer elements for receiving respectively each video signal pulse directly from the camera and each most recently delayed video signal, and for passing either the directly received pulse or the delayed pulse, depending upon the relative magnitude of the two pulses. Since pixel artifact pulses are typically more positive than non-artifacts pulses, the signal transfer elements generally pass the more negative video signal pulses so that the pixel artifact pulses are suppressed when they arrive at the transfer elements.
157 Citations
13 Claims
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1. In a charge-coupled device video camera for producing a video image signal composed of a series of pulses, each representing a pixel, from which a video image may be developed, a pixel artifact filter for filtering pixel artifact pulses which differ in magnitude from next adjacent non-artifact pulses, said filter comprising:
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delay means for receiving the video image signal produced by the camera, and for delaying each video image signal pulse of the signal by a predetermined amount, and means for receiving each non-delayed video image signal pulse directly and unmodified from the camera, pairing each non-delayed pulse and most recently delayed pulse, and for passing either said each non-delayed pulse or said each delayed pulse, depending upon the relative magnitude of the pulses. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A blemish suppression circuit for suppressing pixel blemishes which may occur in video images represented in a video image signal composed of a series of electrical pulses, with each pulse representing a pixel in the image, each pixel blemish characterized by an increase in magnitude of the pulse representing said each pixel blemish, said suppression circuit comprising:
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input means for receiving the video image signal pulses, delaying means for successively delaying the received pulses by approximately a one pulse width duration, output means for outputting the pulses, means for receiving and pairing a non-delayed pulse unmodified and direct from the input means and a delayed pulse from the delaying means, and for suppressing an artifact pulse of each pair which is significantly greater in magnitude than a non-artifact pulse of each pair, and means for passing said non-artifact pulse to the output means. - View Dependent Claims (10, 11, 12)
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13. In a charge-coupled device video camera for producing a video image signal composed of a series of pulses, each representing a pixel, for developing a video image, a method of filtering pixel artifact pulses which differ in magnitude from adjacent non-artifact pulses, said method comprising:
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(a) receiving the video image signal produced by the video camera; (b) delaying the pulses of the video image signal for a time approximately equal to the time duration of one pulse; (c) pairing each video image signal pulses directly and unmodified from the camera wherein each pair of pulses composed of the most recently received non-delayed pulse and the most recently delayed pulse; (d) suppressing an artifact pulse of each pair which is significantly greater in magnitude that a non-artifact pulse of each pair; and (e) passing the non-artifact pulse to an output.
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Specification