High resolution color television signal transmission system and receiver utilizing motion information of a picture

• US 4,885,631 A
• Filed: 08/19/1988
• Issued: 12/05/1989
• Est. Priority Date: 03/18/1983
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yoshigi, Hiroshi, Jusa, Hidehiko, Hirano, Yasuhiro, Fukinuki, Takahiko
• Primary Examiner(s): Shepperd, John W.
• Application Number:
  US07/233,975
• Time in Patent Office: 473 Days
• Field of Search: 358/21 R, 358/105, 358/31, 358/11, 358/12
• US Class Current: 348/436.1
• CPC Class Codes: H04N 11/28 involving bandwidth reduction, e.g. subsampling
• CPC Class Codes: H04N 5/9201 involving the multiplexing of an additional signal and the video signal
• CPC Class Codes: H04N 7/12 Systems in which the television signal is transmitted via one channel or a plurality of parallel channels, the bandwidth of each channel being less than the bandwidth of the television signal H04N7/24 takes precedence

Abstract

A television signal transmission system having an improved receiver which system is capable of transmitting a wide-band television video signal in a frequency band narrower than the frequency band of the television video signal is a multiplex video signal and the receiver reproduces a luminance signal and color signal from the multiplexed video signal. The receiver includes a motion detector for detecting motion information of a picture from the multiplex video signal and a separator for separating signals in response to the detected motion information to thereby form a picture of high quality utilizing the motion information.

Claims

1. A color television signal transmission system comprising:

(a) sending means including first means for obtaining a luminance signal and a color signal of a video signal, first modulating means for modulating a first subcarrier by said color signal in order to obtain a modulated color signal, frequency converting means for converting one part of said luminance signal, which has a horizontal frequency higher than a predetermined horizontal frequency, into a first luminance signal having a horizontal frequency lower than said predetermined horizontal frequency and temporal-vertical frequencies different from temporal-vertical frequencies of said modulated color signal, and multiplexing means for multiplexing another part of said luminance signal having a horizontal frequency lower than said predetermined horizontal frequency, said modulated color signal and said first luminance signal in order to produce a multiplexed video signal of a color television signal to be transmitted;

(b) transmission means for transmitting said multiplexed video signal within a horizontal frequency band lower than said predetermined horizontal frequency; and

(c) receiving means for reproducing said luminance signal and said color signal from said multiplexed video signal and including motion detecting means for detecting motion information of a picture from said multiplexed video signal, separating means for separating said another part of said luminance signal, said first luminance signal and said modulated color signal in response to said detected motion information, first demodulating means for reproducing said color signal from said modulated color signal, and second demodulating means for reproducing said one part of said luminance signal from said first luminance signal;

wherein said motion detecting means includes first motion detecting circuit means for detecting first motion information from a horizontal frequency component lower than the horizontal frequency of said modulated color signal and luminance signal of a frame difference signal between a first signal having motion which is to be detected and a second signal separated by a frame period from said first signal, and second motion detecting circuit means for detecting at least one of second motion information obtained from a sum of two of frame difference signals of two scanning lines vertically adjacent to a line on which said first signal is included and third motion information obtained from two frame difference signals on a scanning line having the same vertical position.

2. A color television signal transmission system according to claim 1, wherein said frequency converting means comprises:

carrier generating means for generating a second subcarrier having a temporal-vertical frequency in line symmetry to a temporal-vertical frequency of said first subcarrier in a two dimensional frequency region represented by temporal and vertical frequency axes arranged perpendicular to each other;

amplitude modulating means for modulating said second subcarrier by said one part of said luminance signal; and

filter means for inputting an output signal of said amplitude modulating means and passing a frequency component having frequencies lower than said predetermined horizontal frequency.

3. A color television signal transmission system according to claim 2, wherein said modulated color signal and said another part of said luminance signal form a video signal of the NTSC color television system.

4. A color television receiver comprising:

receiving means for receiving a multiplexed color television signal including a luminance signal, a modulated color signal and a modulated luminance signal having a temporal-vertical frequency different from a temporal-vertical frequency of said modulated color signal;

first detecting means for detecting motion information of a picture from said multiplexed color television signal;

separating means for separating said luminance signal, said modulated color signal and said modulated luminance signal in response to said detected motion information;

first modulation means for demodulating said modulated luminance signal separated by said separating means and for producing a first luminance signal having a horizontal frequency higher than a predetermined horizontal frequency;

second demodulating means for demodulating said modulator color signal separated by said separating means and for producing a color difference signal;

interpolation circuit means for forming an interpolated luminance signal and an interpolated color difference signal from said luminance signal, said first luminance signal and said color difference signal in response to said detected motion information; and

converting means for converting said luminance signal, said first luminance signal, said color difference signal and output signals of said interpolation circuit means into sequentially scanned video signals;

wherein said first detecting means includes first motion detecting circuit means for detecting first motion information from a horizontal frequency component lower than the horizontal frequency of said modulated color signal and luminance signal of a frame difference signal between a first signal having motion which is to be detected and a second signal separated by a frame period from said first signal, and second motion detecting circuit means for detecting at least one of second motion information obtained from a sum of two of frame difference signals of two scanning lines vertically adjacent to a line on which said first signal is included and third motion information obtained from two frame difference signals on a scanning line having the same vertical position.

5. A color television receiver according to claim 4, wherein said modulated luminance signal is a signal including a second subcarrier having a temporal-vertical frequency in line symmetry with a temporal-vertical frequency of a first subcarrier of said modulated color signal in a two dimensional frequency region represented by temporal and vertical frequency axes arranged perpendicular to each other, and a luminance signal modulated by said second subcarrier and a color signal modulated by said first subcarrier.

6. A color television receiver according to claim 5, wherein said luminance signal and said modulated color signal form a video signal of the NTSC color television system.