Method and apparatus for improving quality of composite video signal and method and apparatus for decoding composite video signal

An apparatus for improving the quality of a composite video signal comprising:

• an edge detecting unit respectively detecting a first edge from a luminance information signal, a second edge from a first chrominance information signal, and a third edge from a second chrominance information signal;
• an artifact region detecting unit detecting an artifact region using the first, and the second and the third edges;
• a filtering unit filtering the artifact region,
• wherein said artifact region is obtained by removing the first edge of the luminance information signal from the second edge of the first chrominance information signal and the third edge of the second chrominance information signal.

A method for decoding a composite video signal comprising:

• separating an input composite video signal into a luminance information signal, a first chrominance information signal, and a second chrominance information signal;
• respectively detecting a first edge from the luminance information signal, a second edge from the first chrominance information signal, and a third edge from the second chrominance information signal;
• detecting an artifact region using the first, the second, and the third edges;
• filtering the artifact region from the luminance information signal, the first chrominance information signal and the second chrominance information signal to generate a filtered luminance information signal and a filtered chrominance information signal;
• and
• converting the filtered luminance information signal and the filtered chrominance information signal into an RGB color space,
• wherein said artifact region is obtained by removing the first edge of the luminance information signal from the second edge of the first chrominance information signal and the third edge of the second chrominance information signal.

An apparatus for decoding a composite video signal comprising:

• a luminance and chrominance signal separating unit separating an input composite video signal into a luminance information signal, a first chrominance information signal, and a second chrominance information signal;
• an edge detecting unit respectively detecting a first edge from the luminance information signal, a second edge from the first chrominance information signal, and a third edge from the second chrominance information signal;
• an artifact region detecting unit detecting an artifact region using the first, the second and the third edges;
• a filtering unit filtering the artifact region from the luminance information signal and the first chrominance information signal, and the second chrominance information signal to generate a filtered luminance information signal and a filtered chrominance information signal;
• and
• a color space converting unit converting the filtered luminance information signal and the filtered chrominance information signal into an RGB color space,
• wherein said artifact region is obtained by removing the first edge of the luminance information signal from the second edge of the first chrominance information signal and the third edge of the second chrominance information signal.