Circuit for color separation and contour correction

• US 5,285,267 A
• Filed: 02/19/1993
• Issued: 02/08/1994
• Est. Priority Date: 02/21/1992
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lim, Jong-Gyun
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): HSIA, SHERRIE Y
• Application Number:
  US08/020,833
• Time in Patent Office: 354 Days
• Field of Search: 358/31, 358/36, 358/39, 358/40, 358/37, 358/96, 358/162, 358/48
• US Class Current: 348/663
• CPC Class Codes: H04N 23/84 for processing colour signals
• CPC Class Codes: H04N 25/136 using complementary colours
• CPC Class Codes: H04N 9/646 for image enhancement, e.g. vertical detail restoration, cross-colour elimination, contour correction, chrominance trapping filters

Abstract

A circuit for a video camera for color separation and contour correction which can perform color separation and contour correction of a signal from a charge coupled device image sensor specifically utilizing two 1H (1 horizontal period) delay elements. The circuit adds a 2H delayed chrominance signal from a delay unit and a current input chrominance signal. This sum is then decreased by one-half. The circuit separates red and blue components of the chrominance signals decreased by half and from the 1H delayed chrominance signal from the delay unit. Next, vertical and horizontal contour correcting signals are generated in response to the 1H delayed chrominance signal from the delay unit and in response to the output of an amplifying unit. Thus, the present invention uses two 1H delay elements to perform color separation as well as contour correction to thereby simplify the overall circuit design.

Claims

1. A circuit for color separation and contour correction, comprising:

delay means for receiving and delaying an input chrominance signal and for outputting 1H delayed and 2H delayed chrominance signals delayed by one and two horizontal periods, respectively;

first adding means for adding said 2H delayed chrominance signal to a non-delayed input chrominance signal;

amplifying means for decreasing by one-half an output of said first adding means; and

chrominance signal separation means for separating red and blue components of a chrominance signal output from said amplifying means and red and blue components of the 1H delayed chrominance signal output from said delay means, the chrominance signal output from said amplifying means and the 1H delayed chrominance signal output from said delay means being used to produce a contour corrected output signal.

2. A circuit for color separation and contour correction as defined in claim 1, further comprising:

contour correcting means for generating vertical and horizontal contour correcting signals in response to the 1H delayed chrominance signal from the delay means and an output of the amplifying means; and

second adding means for adding said vertical and horizontal contour correcting signals output from the contour correcting means to the 1H delayed chrominance signal to produce a contour corrected luminance signal.

3. A circuit for color separation and contour correction as defined in claim 1, wherein said chrominance signal separation means comprises:

a color integrating portion for integrating, said chrominance signal output from the amplifying means and the 1H delayed chrominance signal from the delay means; and

a sample/hold portion for sampling and holding a chrominance signal output from the color integrating portion.

4. A circuit for color separation and contour correction as defined in claim 3, wherein said chrominance signal separation means further comprises:

a subtracter for extracting red and blue components of the chrominance signals in response to signals output from the sample/hold portion; and

an adder for generating a luminance signal in response to signals output from the sample/hold portion.

5. A circuit for color separation and contour correction as defined in claim 2, wherein said contour correcting means comprises:

a vertical contour correcting portion for generating said vertical contour correcting signal from said 1H delayed chrominance signal output from the delay means and said chrominance signal output from the amplifying means; and

a horizontal contour correcting means for generating said horizontal contour correcting signal from the 1H delayed chrominance signal output from the delay means.

6. A circuit for color separation and contour correction as defined in claim 5, wherein said contour correcting means further comprises:

an adder for adding the horizontal contour correcting signal from the horizontal contour correcting portion and the vertical contour correcting signal from the vertical contour correcting portion; and

an aperture compressor for compressing the vertical and horizontal contour correcting signals from the adder.