← Back to Patent Explorer
US5121209A Expired / Lapsed US ⏱️ 0.0 years remaining

Sharpness control for a television image

Assignee: RCA Licensing Corp
•
Filing: 1990-10-01
•
Granted: 1992-06-09
•
Expires: 2010-10-01
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A video signal processing system includes a signal interpolator associated with time compression/expansion apparatus. The interpolator is preceded by a high frequency peaking network which responds to a variable control signal representative of a desired amount of displayed image sharpness. In a disclosed embodiment the peaking network responds to a control signal which is a function of a distance between image pixels, and a variable signal from a viewer adjustable image sharpness control.

Inventors

  • 👤 Terrence R. Smith
  • 👤 Michael A. Isnardi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 22:49
CPC Classifications
H; H04; H04N; H04N9/00; H04N5/00; H04N5/14; H04N5/20; H04N5/205; H04N5/208

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 143 words
In a system for processing a video signal containing picture element image information to be displayed, apparatus for modifying the high frequency response of said video signal comprising: a video signal interpolator having an input and an output and disposed in a path conveying said video signal; a peaking processor disposed in said video signal path for modifying the high frequency reponse of a video output signal from said interpolator; an image sharpness processor for generating a variable sharpness control signal including a sharpness control first component independent of distance between pixels and a second components representative of a distance between pixels; and means for applying said sharpness control signal to said peaking processor for controlling the operation thereof to variably modify said high frequency response so that said high frequency response varies as a function of both said first and second components.
Claim 2
Dependent Claim 143 words
In a system for processing a video signal containing picture element image information to be displayed, apparatus for modifying the high frequency response of said video signal comprising: a video signal interpolator having an input and an output and disposed in a path conveying said video signal; a peaking processor disposed in said video signal path for modifying the high frequency reponse of a video output signal from said interpolator; an image sharpness processor for generating a variable sharpness control signal including a sharpness control first component independent of distance between pixels and a second components representative of a distance between pixels; and means for applying said sharpness control signal to said peaking processor for controlling the operation thereof to variably modify said high frequency response so that said high frequency response varies as a function of both said first and second components.
Claim 3
Dependent Claim 23 words
Apparatus according to claim 1, wherein said sharpness processor includes a manual sharpness control device operable by a viewer of a displayed image.
Claim 4
Dependent Claim 18 words
Apparatus according to claim 1, wherein said distance representative second component exhibits a value between zero and unity.
Claim 5
Dependent Claim 29 words
Apparatus according to claim 1, wherein said video signal with a modified high freqency response exhibits a maximum response over a plurality of points, including the midpoint, between pixels.
Claim 6
Dependent Claim 124 words
Apparatus according to claim 1, wherein said sharpness processor includes a detector responsive to a first signal DX representative of a fractional distance between a calculated input pixel position and the next lower existing pixel position, and to a second signal defined by the expression 1-DX, for providing an output representative of the smaller value of signals DX and 1-DX; a sharpness control network for generating a first sharpness control signal representative of a sharpness gain characteristic, and a second sharpness control signal for limiting said gain characteristic; a signal multiplier responsive to said first sharpness control signal and to an output signal from said detector; and a limiter responsive to an output signal from said multiplier and to said second sharpness control signal.

References Cited (Backward Citations)

US4090217A Cited
US4402006A Cited
US4399460A Cited
US4538578A Cited
US4623913A Cited
US4698673A Cited
US4816899A Cited
US4862271A Cited
US4783840A Cited
US4963958A Cited
US5055916A Cited
US5047856A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-06-09 1995-12-09 1996-06-09 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-06-09 1999-12-09 2000-06-09 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-06-09 2003-12-09 2004-06-09 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag