Contour enhancement processing circuit, contour enhancement processing method, and television camera

A contour enhancement processing method used in a video signal processing unit of a television camera, comprising:

• a first delay means for delaying an inputted video signal;
• a contour extraction means for extracting a contour component signal from the video signal;
• a second delay means for delaying the contour component signal;
• a video level detection means for detecting a video level of the video signal and outputting the video level;
• a crisp means for removing a noise component from the contour component signal transmitted from the second delay circuit using a crisp means for removing a noise component from the contour component signal transmitted from the second delay means and outputting a contour signal;
• a crisp gain control means for obtaining a gain for controlling amplification of a crisp original signal for generating the crisp signal according to the video level and outputting the gain as a crisp gain;
• a multiplication means for multiplying the crisp gain and the crisp original signal to generate the crisp signal and outputting the crisp signal to the crisp means;
• a gain means for amplifying the contour signal from which the noise component is removed in the crisp means;
• and
• an addition means for adding the video signal transmitted from the first delay means and the amplified contour signal transmitted from the gain means and outputting a contour-enhanced video signal,
• wherein the crisp gain control means sets a video level of 100% as a normalized reference level, sets a gain at the normalized reference level as 1, and outputs a crisp gain according to the video level from the video level detection means with respect to the normalized reference level,
• the crisp gain control means outputs a crisp gain according to a video level on a line connecting a first point where the video level is zero and the crisp gain is zero and a second point where the video level is 100% and the crisp gain is 1, when the video level is indicated on a horizontal axis and the crisp gain is indicated on a vertical axis, and
• the crisp gain control means shifts the first point in a horizontal axis direction or a vertical axis direction according to a tilt signal from the outside for changing a slope of the line connecting the first point and the second point.

A television camera including a prism configured to take a video image inputted from a lens, an imaging element, a CDS (Correlated Double Sampling) circuit, a VGA (Variable Gain Amplification) circuit, an A/D converter, a video signal processing unit, a video signal output unit and a timing generation unit, wherein:

• the video signal processing unit comprises:
• a first delay means for delaying an inputted video signal;
• a contour extraction means for extracting a contour component signal from the video signal;
• a second delay means for delaying the contour component signal;
• a video level detection means for detecting a video level of the video signal and outputting the video level;
• a crisp means for removing a noise component from the contour component signal transmitted from the second delay circuit using a crisp means for removing a noise component from the contour component signal transmitted from the second delay means and outputting a contour signal;
• a crisp gain control means for obtaining a gain for controlling amplification of a crisp original signal for generating the crisp signal according to the video level and outputting the gain as a crisp gain;
• a multiplication means for multiplying the crisp gain and the crisp original signal to generate the crisp signal and outputting the crisp signal to the crisp means;
• a gain means for amplifying the contour signal from which the noise component is removed in the crisp means;
• and
• an addition means for adding the video signal transmitted from the first delay means and the amplified contour signal transmitted from the gain means and outputting a contour-enhanced video signal,
• wherein the crisp gain control means sets a video level of 100% as a normalized reference level, sets a gain at the normalized reference level as 1, and outputs a crisp gain according to the video level from the video level detection means with respect to the normalized reference level,
• the crisp gain control means outputs a crisp gain according to a video level on a line connecting a first point where the video level is zero and the crisp gain is zero and a second point where the video level is 100% and the crisp gain is 1, when the video level is indicated on a horizontal axis and the crisp gain is indicated on a vertical axis, and
• the crisp gain control means shifts the first point in a horizontal axis direction or a vertical axis direction according to a tilt signal from the outside for changing a slope of the line connecting the first point and the second point.