US4918528A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Contour correction device
Assignee: Mitsubishi Electric Corp
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Filing: 1988-05-20
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Granted: 1990-04-17
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Expires: 2008-05-20
Abstract
Abstract In order to attain a higher sharpness of a television image by improving the transient of signals corresponding to the contour portion of the image, an input signal and two other signals obtained through delaying the input signal are used such that the transient portion is detected through computation of these three signals and one of these three signals is selected and output. According to this arrangement, the sharpness and the fineness of the input image can be improved without being accompanied by image saturation.
Inventors
- 👤 Tomonori Oohashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:01
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H04N5/142; H04N5/20; H04N5/205; H04N5/208
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
274 words
A contour correction device comprising: first delay means for delaying an input image signal by a first predetermined delay time; second delay means for delaying said input image signal by a second predetermined delay time which is longer than said first predetermined delay time; means for computing an absolute value A of the difference in the amplitude between an output signal from said first delay means and said input image signal; means for computing an absolute value B of the difference in the amplitude between said output signal from said first delay means and an output from the second delay means; first comparison means for comparing said absolute values A and B and for producing an output signal representative of the result of the comparison throughout a period in which a condition A<B or A>B is met; means for computing an absolute value C of the difference between said absolute values A and B; second comparison means for comparing said absolute value C with a threshold value N and for producing an output signal representative of the result of the comparison throughout a period in which a condition of C>N or C<N is met; and means for outputting a contour enhanced image signal, said means selectively outputting, in accordance with the two comparison results, said input image signal throughout a period in which both the conditions C>N and A<B are simultaneously met, said output signal from said first delay means throughout a period in which the condition of C<N is met, and said output signal from said second delay means throughout a period in which both the conditions C>N and A>B are simultaneously met.
Claim 2
Dependent Claim
274 words
A contour correction device comprising: first delay means for delaying an input image signal by a first predetermined delay time; second delay means for delaying said input image signal by a second predetermined delay time which is longer than said first predetermined delay time; means for computing an absolute value A of the difference in the amplitude between an output signal from said first delay means and said input image signal; means for computing an absolute value B of the difference in the amplitude between said output signal from said first delay means and an output from the second delay means; first comparison means for comparing said absolute values A and B and for producing an output signal representative of the result of the comparison throughout a period in which a condition A<B or A>B is met; means for computing an absolute value C of the difference between said absolute values A and B; second comparison means for comparing said absolute value C with a threshold value N and for producing an output signal representative of the result of the comparison throughout a period in which a condition of C>N or C<N is met; and means for outputting a contour enhanced image signal, said means selectively outputting, in accordance with the two comparison results, said input image signal throughout a period in which both the conditions C>N and A<B are simultaneously met, said output signal from said first delay means throughout a period in which the condition of C<N is met, and said output signal from said second delay means throughout a period in which both the conditions C>N and A>B are simultaneously met.
Claim 3
Dependent Claim
23 words
The contour correction device of claim 1 wherein said second predetermined delay time is twice as long as said first predetermined delay time.
Claim 4
Dependent Claim
268 words
A contour correction device comprising: first delay means for delaying an input image signal by a predetermined delay time; second delay means for delaying an output signal of said first delay means by said predetermined delay time; means for computing an absolute value A of the difference in the amplitude between an output signal from said first delay means and said input image signal; means for computing an absolute value B of the difference in the amplitude between said output signal from said first delay means and an output from the second delay means; first comparison means for comparing said absolute values A and B and for producing an output signal representative of the result of the comparison throughout a period in which a condition A<B or A>B is met; means for computing an absolute value C of the difference between said absolute values A and B; second comparison means for comparing said absolute value C with a threshold value N and for producing an output signal representative of the result of the comparison throughout a period in which a condition of C>N or C<N is met; and means for outputting a contour enhanced image signal, said means for selectively outputting, in accordance with the two comparison results, said input image signal throughout a period in which both the conditions C>N and A<B are simultaneously met, said output signal from said first delay means throughout a period in which the condition of C<N is met, and said output signal from said second delay means throughout a period in which both the conditions C>N and A>B are simultaneously met.
Claim 5
Dependent Claim
268 words
A contour correction device comprising: first delay means for delaying an input image signal by a predetermined delay time; second delay means for delaying an output signal of said first delay means by said predetermined delay time; means for computing an absolute value A of the difference in the amplitude between an output signal from said first delay means and said input image signal; means for computing an absolute value B of the difference in the amplitude between said output signal from said first delay means and an output from the second delay means; first comparison means for comparing said absolute values A and B and for producing an output signal representative of the result of the comparison throughout a period in which a condition A<B or A>B is met; means for computing an absolute value C of the difference between said absolute values A and B; second comparison means for comparing said absolute value C with a threshold value N and for producing an output signal representative of the result of the comparison throughout a period in which a condition of C>N or C<N is met; and means for outputting a contour enhanced image signal, said means for selectively outputting, in accordance with the two comparison results, said input image signal throughout a period in which both the conditions C>N and A<B are simultaneously met, said output signal from said first delay means throughout a period in which the condition of C<N is met, and said output signal from said second delay means throughout a period in which both the conditions C>N and A>B are simultaneously met.
Claim 6
Independent Claim
261 words
A method of contour correction comprising the steps of: delaying an input image signal by a first predetermined delay time in a first delay means; delaying said input image signal by a second predetermined delay time, which is longer than said first predetermined delay time, in a second delay means; computing an absolute value A of the difference in the amplitude between an output signal from said first delay means and said input image signal; computing an absolute value B of the difference in the amplitude between said output signal from said first delay means and an output from the second delay means; comparing said absolute values A and B and producing an output signal representative of the result of the comparison throughout a period in which a condition A<B or A>B is met; computing an absolute value C of the difference between said absolute values A and B; comparing said absolute value C with a threshold value N and producing an output signal representative of the result of the comparison throughout a period in which a condition of C>N or C<N is met; and outputting a contour enhanced image signal by selectively outputting, in accordance with the two comparison results, said input image signal throughout a period in which both the conditions C>N and A<B are simultaneously met, said output signal from said first delay means throughout a period in which the condition of C<N is met, and said output signal from said second delay means throughout a period in which both the conditions C>N and A>B are simultaneously met.
Claim 7
Independent Claim
261 words
A method of contour correction comprising the steps of: delaying an input image signal by a first predetermined delay time in a first delay means; delaying said input image signal by a second predetermined delay time, which is longer than said first predetermined delay time, in a second delay means; computing an absolute value A of the difference in the amplitude between an output signal from said first delay means and said input image signal; computing an absolute value B of the difference in the amplitude between said output signal from said first delay means and an output from the second delay means; comparing said absolute values A and B and producing an output signal representative of the result of the comparison throughout a period in which a condition A<B or A>B is met; computing an absolute value C of the difference between said absolute values A and B; comparing said absolute value C with a threshold value N and producing an output signal representative of the result of the comparison throughout a period in which a condition of C>N or C<N is met; and outputting a contour enhanced image signal by selectively outputting, in accordance with the two comparison results, said input image signal throughout a period in which both the conditions C>N and A<B are simultaneously met, said output signal from said first delay means throughout a period in which the condition of C<N is met, and said output signal from said second delay means throughout a period in which both the conditions C>N and A>B are simultaneously met.
Claim 8
Dependent Claim
24 words
The method of contour correction of claim 4 wherein said second predetermined delay time is twice as long as said first predetermined delay time.
Claim 9
Independent Claim
254 words
A method of contour correction comprising the steps of: delaying an input image signal by a predetermined delay time in a first delay means; delaying an output signal of said first delay means, by said predetermined delay time, in a second delay means; computing an absolute value A of the difference in the amplitude between an output signal from said first delay means and said input image signal; computing an absolute value B of the difference in the amplitude between said output signal from said first delay means and an output from the second delay means; comparing said absolute values A and B and producing an output signal representative of the result of the comparison throughout a period in which a condition A<B or A>B is met; computing an absolute value C of the difference between said absolute values A and B; comparing said absolute value C with a threshold value N and producing an output signal representative of the result of the comparison throughout a period in which a condition of C>N or C<N is met; and outputting a contour enhanced image signal by selectively outputting, in accordance with the two comparison results, said input image signal throughout a period in which both the conditions C>N and A<B are simultaneously met, said output signal from said first delay means throughout a period in which the condition of C<N is met, and said output signal from said second delay means throughout a period in which both the conditions C>N and A>B are simultaneously met.
Claim 10
Independent Claim
254 words
A method of contour correction comprising the steps of: delaying an input image signal by a predetermined delay time in a first delay means; delaying an output signal of said first delay means, by said predetermined delay time, in a second delay means; computing an absolute value A of the difference in the amplitude between an output signal from said first delay means and said input image signal; computing an absolute value B of the difference in the amplitude between said output signal from said first delay means and an output from the second delay means; comparing said absolute values A and B and producing an output signal representative of the result of the comparison throughout a period in which a condition A<B or A>B is met; computing an absolute value C of the difference between said absolute values A and B; comparing said absolute value C with a threshold value N and producing an output signal representative of the result of the comparison throughout a period in which a condition of C>N or C<N is met; and outputting a contour enhanced image signal by selectively outputting, in accordance with the two comparison results, said input image signal throughout a period in which both the conditions C>N and A<B are simultaneously met, said output signal from said first delay means throughout a period in which the condition of C<N is met, and said output signal from said second delay means throughout a period in which both the conditions C>N and A>B are simultaneously met.
References Cited (Backward Citations)
SU562948A1
Cited
JPS5416923A
Cited
US4677461A
Cited
US4698673A
Cited
US4706113A
Cited
US4758891A
Cited
US4839725A
Cited
JPS63292776A
Cited
JPS63302675A
Cited
JPS6424681A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-16 | 1993-10-16 | 1994-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-16 | 1997-10-16 | 1998-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-16 | 2001-10-16 | 2002-04-17 | $7700.00 | Window Closed / Lapsed |