Back to results
US 2002/0057375 A1Published application
Video signal receiver with level limited output
AssigneeFujitsu Limited
InventorsHideki Miyasaka, Hiroshi Ohtsuru, Tetsuya Yasui
Life of this patent
Estimating the term…
Abstract
A video signal processing apparatus includes a receiver receiving an incoming video signal and producing an output video signal in response thereto, a limit setup unit setting up at least one of an upper limit value and a lower limit value for the output video signal, and a limiter supplied with the output video signal from the receiver and further with at least one of the upper limit value and the lower limit value from the limit setup unit, wherein the limiter limits a level of the output video signal produced by the receiver, by comparing the level of the output video signal according to any of the upper limit value and the lower limit value.
Claims15
A video signal processing apparatus, comprising:
- a receiver receiving an incoming video signal, said receiver further producing an output video signal in response thereto;
- a limit setup unit setting up at least one of an upper limit value and a lower limit value for said output video signal;
- and
- a limiter supplied with said output video signal from said receiver and further with at least one of said upper limit value and said lower limit value from said limit setup unit, said limiter limiting a level of said output video signal produced by said receiver, by comparing said level of said output video signal according to any of said upper limit value and lower limit value;
- wherein said video signal processor is supplied with said video signal in the form of a digital component signal, and wherein said limit setup unit includes a register holding said upper limit value,
- said limiter including:
- a first operational unit supplied with said digital component signal and calculating an amplitude of a color signal contained in an analog composite signal converted from said digital component signal;
- a second operational unit supplied with said digital component signal and calculating an amplitude of a luminance signal contained in said analog composite signal converted from said digital component signal;
- a third operational unit multiplying an amplitude factor to a first color difference signal of said digital component signal, said amplitude factor being a ratio of an amplitude of a modified color signal to said amplitude of said color difference signal, said modified color signal having said amplitude determined such that a sum of said amplitude of said modified color difference signal and said amplitude of said luminance signal does not exceed said upper limit value;
- and
- a fourth operational unit multiplying said amplitude factor to a second color difference signal of said digital component signal.
8 more elements
A video signal processing apparatus, comprising:
- a receiver receiving an incoming video signal, said receiver further producing an output video signal in response thereto;
- a limit setup unit setting up at least one of an upper limit value and a lower limit value for said output video signal;
- and
- a limiter supplied with said output video signal from said receiver and further with at least one of said upper limit value and said lower limit value from said limit setup unit, said limiter limiting a level of said output video signal produced by said receiver, by comparing said level of said output video signal according to any of said upper limit value and lower limit value;
- wherein said video signal processor is supplied with said video signal in the form of a digital component signal, and wherein said limit setup unit includes a register holding said lower limit value,
- said limiter including:
- a first operational unit supplied with said digital component signal and calculating an amplitude of a color signal contained in an analog composite signal converted from said digital component signal;
- a second operational unit supplied with said digital component signal and calculating an amplitude of a luminance signal contained in said analog composite signal converted from said digital component signal;
- a third operational unit multiplying an amplitude factor to a first color difference signal of said digital component signal,
- said amplitude factor being a ratio of an amplitude of a modified color signal to said amplitude of said color difference signal, said modified color signal having said amplitude determined such that a sum of said amplitude of said modified color difference signal and said amplitude of said luminance signal does not exceed said lower limit value in a negative direction;
- and
- a fourth operational unit multiplying said amplitude factor to a second color difference signal of said digital component signal.
9 more elements
A video signal processing apparatus, comprising:
- a receiver receiving an incoming video signal, said receiver further producing an output video signal in response thereto;
- a limit setup unit setting up at least one of an upper limit value and a lower limit value for said output video signal;
- and
- a limiter supplied with said output video signal from said receiver and further with at least one of said upper limit value and said lower limit value from said limit setup unit, said limiter limiting a level of said output video signal produced by said receiver, by comparing said level of said output video signal according to any of said upper limit value and lower limit value;
- wherein said video signal processor is supplied with said video signal in the form of a digital component signal, and wherein said limit setup unit includes a first register holding said upper limit value and a second register holding said lower limit value,
- said limiter including:
- a first operational unit supplied with said digital component signal and calculating an amplitude of a color signal contained in an analog composite signal converted from said digital component signal;
- a second operational unit supplied with said digital component signal and calculating an amplitude of a luminance signal contained in said analog composite signal converted from said digital component signal;
- a third operational unit multiplying an amplitude factor to a first color difference signal of said digital component signal,
- said amplitude factor being a ratio of an amplitude of a modified color signal to said amplitude of said color difference signal, said modified color signal having said amplitude determined such that a sum of said amplitude of said modified color difference signal and said amplitude of said luminance signal does not exceed said upper limit value in a positive direction and further said lower limit value in a negative direction;
- and
- a fourth operational unit multiplying said amplitude factor to a second color difference signal of said digital component signal.
9 more elements
Dependencies are inferred from the claim text.