US5144686A
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Mtf compensation apparatus
Assignee: Panasonic Holdings Corp
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Filing: 1991-02-07
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Granted: 1992-09-01
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Expires: 2011-02-07
Abstract
Abstract In a picture processing apparatus, respective results of subtraction calculation between the relevant pixel and the reference pixels are obtained by a subtraction arithmetic circuit. The resultant differences are converted nonlinearly by a nonlinear conversion circuit, and thereafter a summation calculation of these resultant differences are performed by a first addition arithmetic circuit. The obtained result is added to data of the relevant pixel by a second addition arithmetic circuit; thereby achieving MTF correction. By adequately selecting the input-output characteristic of the nonlinear conversion circuit, a stable contour line enhancement is achievable even when noise is present in the picture signal.
Inventors
- 👤 Yumiba: Takashi
- 👤 Haruo Yamashita
- 👤 Shinichi Konishi
- 👤 Yoshiteru Namoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:04
CPC Classifications
G; G06; G06T; G06T1/00; G06T5/00; G06T5/20
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
125 words
A picture processing apparatus for sharpening a picture image in which a plurality of line memories each store a line of a picture image signal and a latching means stores a relevant pixel in said line memories, said picture processing apparatus comprising: subtraction means for subtracting from a datum of said relevant pixel, N (N≧=1) respective data of N pixels which are nearest neighbors of said relevant pixel to produce N subtraction outputs; nonlinear conversion means for nonlinearly converting said N subtraction outputs to produce N corresponding conversion outputs; first addition means for adding said N conversion outputs to produce a conversion sum; and second addition means for adding said datum of said relevant pixel and said conversion sum to produce a sharper image pixel.
Claim 2
Dependent Claim
125 words
A picture processing apparatus for sharpening a picture image in which a plurality of line memories each store a line of a picture image signal and a latching means stores a relevant pixel in said line memories, said picture processing apparatus comprising: subtraction means for subtracting from a datum of said relevant pixel, N (N≧=1) respective data of N pixels which are nearest neighbors of said relevant pixel to produce N subtraction outputs; nonlinear conversion means for nonlinearly converting said N subtraction outputs to produce N corresponding conversion outputs; first addition means for adding said N conversion outputs to produce a conversion sum; and second addition means for adding said datum of said relevant pixel and said conversion sum to produce a sharper image pixel.
Claim 3
Dependent Claim
71 words
An apparatus according to claim 1, wherein said nonlinear conversion means: outputs a conversion output substantially equal to zero when an absolute value of a corresponding subtraction output is less than or equal to a first threshold value; and outputs a conversion output based on a first positively sloped linear function of a corresponding subtraction output when an absolute value of said subtraction output is greater than said first threshold value.
Claim 4
Dependent Claim
72 words
An apparatus according to claim 2, wherein said nonlinear conversion means outputs a conversion output based on a second positively sloped linear function of a corresponding subtraction output when an absolute value of said subtraction output is greater than a second threshold value, said second threshold value being greater than said first threshold value and said second positively sloped linear function having a slope greater than said first positively sloped linear function.
Claim 5
Dependent Claim
72 words
An apparatus according to claim 3, wherein said nonlinear conversion means outputs a conversion output based on a third positively sloped linear function of a corresponding subtraction output when an absolute value of said subtraction output is greater than a third threshold value, said third threshold value being greater than said second threshold value and said third positively sloped linear function having a slope greater than said second positively sloped linear function.
Claim 6
Dependent Claim
28 words
An apparatus according to claim 1, wherein said nonlinear conversion means outputs a conversion output based on a first positively sloped linear function of a corresponding subtraction output.
Claim 7
Dependent Claim
60 words
An apparatus according to claim 5, wherein said nonlinear conversion means outputs a conversion output based on a second positively sloped linear function of a corresponding subtraction output when an absolute value of said subtraction output is greater than a first threshold value, said second positively sloped linear function having a slope less than said first positively sloped linear function.
Claim 8
Dependent Claim
27 words
An apparatus according to claim 1, wherein said nonlinear conversion means outputs a conversion output based on a negatively sloped linear function of a corresponding subtraction output.
Claim 9
Dependent Claim
42 words
An apparatus according to claim 7, wherein said nonlinear conversion means outputs a conversion output based on a positively sloped linear function of a corresponding subtraction output when an absolute value of said subtraction output is greater than a first threshold value.
Claim 10
Dependent Claim
191 words
An apparatus according to claim 1, wherein said nonlinear conversion means: outputs a conversion output substantially equal to zero when an absolute value of a corresponding subtraction output is less than or equal to a first threshold value; outputs a conversion output based on a first positively sloped linear function of a corresponding subtraction output when an absolute value of said subtraction output is greater than said first threshold value; outputs a conversion output based on a second positively sloped linear function of a corresponding subtraction output when an absolute value of said subtraction output is greater than a second threshold value, said second threshold value greater than said first threshold value and said second positively sloped linear function having a slope greater than said first positively sloped linear function; and outputs a conversion output based on a third positively sloped linear function of a corresponding subtraction output when an absolute value of said subtraction output is greater than a third threshold value, said third threshold value greater than said second threshold value and said third positively sloped linear function having a slope greater than said second positively sloped linear function.
Claim 11
Dependent Claim
119 words
A picture processing apparatus for sharpening a picture image comprising: a plurality of line memories each for storing a line of a picture image signal; latching means for storing a relevant pixel in said line memories; subtraction means for subtracting from a datum of said relevant pixel, N (N≧1) respective data of N pixels which are nearest neighbors of said relevant pixel to produce N subtraction outputs; nonlinear conversion means for nonlinearly converting said N subtraction outputs to produce N corresponding conversion outputs; first addition means for adding said N conversion outputs to produce a conversion sum; and second addition means for adding said datum of said relevant pixel and said conversion sum to produce a sharper image pixel.
Claim 12
Dependent Claim
119 words
A picture processing apparatus for sharpening a picture image comprising: a plurality of line memories each for storing a line of a picture image signal; latching means for storing a relevant pixel in said line memories; subtraction means for subtracting from a datum of said relevant pixel, N (N≧1) respective data of N pixels which are nearest neighbors of said relevant pixel to produce N subtraction outputs; nonlinear conversion means for nonlinearly converting said N subtraction outputs to produce N corresponding conversion outputs; first addition means for adding said N conversion outputs to produce a conversion sum; and second addition means for adding said datum of said relevant pixel and said conversion sum to produce a sharper image pixel.
Claim 13
Dependent Claim
118 words
A picture processing apparatus for sharpening a picture image comprising: a plurality of line memories each for storing a line of a picture image signal; latching means for storing a relevant pixel in said line memories; substraction means for subtracting from a datum of said relevant pixel, N (N≧1) respective data of N pixels which are nearest neighbors of said relevant pixel to produce N subtraction outputs; first addition means for adding said N subtraction outputs to produce a conversion sum; nonlinear conversion means for nonlinearly converting said conversion sum to produce a corresponding conversion output; and second addition means for adding said datum of said relevant pixel and said conversion output to produce a sharper image pixel.
Claim 14
Dependent Claim
118 words
A picture processing apparatus for sharpening a picture image comprising: a plurality of line memories each for storing a line of a picture image signal; latching means for storing a relevant pixel in said line memories; substraction means for subtracting from a datum of said relevant pixel, N (N≧1) respective data of N pixels which are nearest neighbors of said relevant pixel to produce N subtraction outputs; first addition means for adding said N subtraction outputs to produce a conversion sum; nonlinear conversion means for nonlinearly converting said conversion sum to produce a corresponding conversion output; and second addition means for adding said datum of said relevant pixel and said conversion output to produce a sharper image pixel.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-01 | 1996-03-02 | 1996-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-01 | 2000-03-02 | 2000-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-01 | 2004-03-02 | 2004-09-01 | $7700.00 | Window Closed / Lapsed |