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

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

a first delay circuit configured to delay an inputted video signal;

a contour extraction circuit configured to extract a contour component signal from the video signal;

a second delay circuit configured to delay the contour component signal;

a video level detection circuit configured to detect a video level of the video signal and output the video level;

a crisp circuit configured to remove a noise component from the contour component signal transmitted from the second delay circuit using a crisp signal for removing the noise component in the contour component signal and output a contour signal;

a crisp gain control circuit configured to obtain a gain for controlling amplification of a crisp original signal for generating the crisp signal according to the video level and output the gain as a crisp gain;

a multiplier configured to multiply the crisp gain and the crisp original signal to generate the crisp signal and output the crisp signal to the crisp circuit;

a gain circuit configured to amplify the contour signal from which the noise component is removed in the crisp circuit; and

an adder configured to add the video signal transmitted from the first delay circuit and the amplified contour signal transmitted from the gain circuit and output a contour-enhanced video signal.

2. The contour enhancement processing circuit of claim 1 , wherein the crisp gain control circuit 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 circuit with respect to the normalized reference level.

3. The contour enhancement processing circuit of claim 2 , wherein the crisp gain control circuit 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.

4. The contour enhancement processing circuit of claim 3 , wherein the crisp gain control circuit 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.

5. 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.

6. 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.