Video signal recording/reproducing system for recording and reproducing video signals in high quality picture television system

• US 5,305,112 A
• Filed: 06/26/1991
• Issued: 04/19/1994
• Est. Priority Date: 06/29/1990
• Status: Expired due to Fees

• Current Assignee: Pioneer Electronic Corporation (Pioneer Corporation)
• Original Assignee: Pioneer Electronic Corporation (Pioneer Corporation)
• Inventors: Shioda, Takehiko, Iwamura, Hiroshi, Yamamoto, Yukinori, Araya, Masahiro
• Primary Examiner(s): Chin, Tommy P.
• Assistant Examiner(s): Truong, Khoi
• Application Number:
  US07/721,867
• Time in Patent Office: 1,028 Days
• Field of Search: 358/310, 358/334, 358/335, 358/11, 358/12, 358/138, 358/140, 358/141, 358/180, 358/14, 360/33.1, 360/35.1, 360/9.1
• US Class Current: 386/309
• CPC Class Codes: H04N 7/012 Conversion between an interlaced and a progressive signal for graphics images G09G2310/0229
• CPC Class Codes: H04N 9/797 for recording the signal in a plurality of channels, the bandwidth of each channel being less than the bandwidth of the signal H04N9/804, H04N9/81, H04N9/82 take precedence
• CPC Class Codes: H04N 9/81 the individual colour picture signal components being recorded sequentially only

Abstract

A video signal recording and reproducing system enables recording and reproducing of a video signal with high quality. The system includes a recording system for recording the video signal on a record medium by means of a median filter and a reproducing system for reproducing the video signal from the record medium. The recording system separates a brightness signal and a color signal from an interlaced scanning signal. The recording system divides picture elements of each line into two phases by sorting the elements such that an element is put into one phase and the next element into the other. The recording system then carries out two-dimensional subsampling to the brightness signal and the color signal to reduce the amount of data. Then, the recording system compresses and time-division multiplexes the brightness signal and the color signal to provide a video signal to be recorded onto a record medium. The reproducing system separates the brightness signal and the color signal from a video signal read out from the record medium, and then interpolates picture elements into the two signals to obtain sequential scanning RGB signals for 525 scanning lines.

Claims

1. A video signal reproducing system for reproducing a video signal that is received from an external source, said external source comprising a median filter for extracting from an input signal a median value from among a first picture element in a first scanning line in a first field, a second picture element in a second scanning line preceding the first scanning line corresponding to said first picture element, and a third picture element in a third line in a second field preceding the first field, the third line being positioned between the first scanning line and the second scanning line;

and a video subsampling means for reducing the amount of data, said video signal reproducing system comprising;

means for receiving the video signal from said external signal source;

a TCI decoder for separating the video signal having line-sequential scanning lines into a brightness signal and a color signal, each of said line-sequential scanning lines being previously compressed in terms of time and time-division multiplexed and having picture elements previously subsampled, said TCI decoder expanding said brightness signal and said color signal relative to time;

first interpolating means for recovering said picture elements from said brightness signal; and

second interpolating means for recovering said picture elements from said color signal, and separating said multiplexed color signal into two color-difference signals; and

a horizontal interpolation circuit, coupled to outputs of said second interpolating means, for horizontally interpolating each of said two color-difference signals.

2. A video signal reproducing system as defined in claim 1, wherein said external signal source comprises a recording means that comprises a video-signal-system converting circuit for converting interlaced scanning lines into line sequential scanning lines, said converting circuit including the median filter for producing an interpolated picture element having a median value of a video signal out of a plurality of picture elements in said interlaced scanning lines.

3. A video signal reproducing system as defined in claim 1, wherein said processing means comprises a video signal interpolating circuit comprising a filter circuit having first and second filters for interpolating subsampled picture elements, said first and second filters being switched to selectively pass interpolated data and central data to thereby simultaneously carry out data shift, zero-data insertion, and two-dimensional filtering.

4. A video signal reproducing system as defined in claim 1, said video signal subsampling means comprising:

a divide-into-two-phase circuit for separating picture elements in each scanning line into two-phase data by sorting an element into one phase and elements adjacent to said element into the other, said two-phase data including a first phase and a second phase;

a switching circuit coupled to outputs of said divide-into-two-phase circuit and having two output terminals each outputting said first phase alternately with said second phase for each scanning line; and

a filter circuit coupled to outputs of said switching circuit and having first and second filters that are switched every scanning line to filter the outputs of said switching circuit, whereby said video signal subsampling means simultaneously carries out two-dimensional filtering, offset sampling, and data shifting of the two-phase data on each scanning line.

5. A video signal reproducing system as defined in claim 1, further comprising:

inverse matrix means for producing three primary color signals from said brightness signal and said two color-difference signals; and

means for converting said three primary color signals into analog signals and outputting said analog signals.

6. A video signal reproducing system as defined in claim 1, wherein said external signal source comprises a recording means that comprises:

television-signal-system converting means for converting a television signal having interlaced scanning lines into a television signal having line sequential scanning lines, said television-signal-system converting means interpolating picture elements in scanning lines of a brightness signal and a color signal of said interlaced scanning lines to produce a line sequential brightness signal and a line sequential color signal, each of which having reduced number of scanning lines;

subsampling means for carrying out two-dimensional subsampling to said line sequential brightness signal to reduce an amount of data thereof, and for thinning out picture elements of each scanning line of said line sequential color signal and then carrying out two-dimensional subsampling to said thinned line sequential color signal;

a TCI encoder for compressing in time each scanning line of said line sequential brightness signal and of said line sequential color signal outputted from said subsampling means, and for time-division multiplexing said line sequential brightness and color signals; and

D/A converting means for converting said time-division multiplexed signal from said TCI encoder into an analog signal.

7. A video signal reproducing system as defined in claim 1, wherein said second interpolating means comprises a vertical interpolating means, coupled to an output of said TCI decoder for receiving said color signal, for inserting zero data to said color signal, and means for interpolating into predetermined positions and recovering picture elements from said color signal and zero data to produce said two color-difference signals.

8. A video signal reproducing system as defined in claim 1, wherein said first interpolating circuit comprises:

means, coupled to an output of said TCI decoder, for receiving said brightness signal;

means for storing and delaying selected picture elements from selected lines of said brightness signal; and

means for multiplying the selected picture elements from the selected lines of the brightness signal so as to generate a reconstructed brightness signal corresponding to the brightness signal of the video signal prior to being recorded on the record medium.

9. A video signal reproducing system for reproducing a video signal, said video signal having been processed by a processing means in which said video signal is filtered by a median filter and subsampled by a video signal subsampling means, said reproducing system comprising:

means for receiving the video signal from an external signal source;

a TCI decoder for separating the video signal having line-sequential scanning lines into a brightness signal and a color signal, each of said line-sequential scanning lines being previously compressed in terms of time and time-division multiplexed and having picture elements previously subsampled, said TCI decoder expanding said brightness signal and said color signal relative to time;

first interpolating means for recovering said picture elements from said brightness signal; and

second interpolating means for recovering said picture elements from said color signal, and separating said multiplexed color signal into two color-difference signals, wherein said external signal source comprises a recording means that comprises;

a vertical interpolating circuit for interpolating picture elements between adjacent scanning lines of a current field of an interlaced scanning video signal by the use of the median filter, said median filter producing an interpolated picture element having a median value of color density of a first picture element in a current line of said current field, a second picture element in a preceding line corresponding to said first picture element of said current field, and a third picture element in a scanning line of a preceding field positioned between said current and preceding lines; and

a vertical filter circuit for producing a weighted sum of said interpolated picture element and picture elements in said adjacent scanning lines, said vertical filter circuit outputting said weighted sum as a new picture element of a sequential scanning video signal.

10. A video signal reproducing system as defined in claim 9, wherein said interlaced scanning video signal is a high definition television signal having 1125 scanning lines, and said sequential scanning video signal has 525 scanning lines.

11. A video signal reproducing system for reproducing a video signal, said video signal having been processed by a processing means in which said video signal is filtered by a median filter and subsampled by a video signal subsampling means, said reproducing system comprising:

means for receiving the video signal from an external signal source;

a TCI decoder for separating the video signal having line-sequential scanning lines into a brightness signal and a color signal, each of said line-sequential scanning lines being previously compressed in terms of time and time-division multiplexed and having picture elements previously subsampled, said TCI decoder expanding said brightness signal and said color signal relative to time;

first interpolating means for recovering said picture elements from said brightness signal; and

second interpolating means for recovering said picture elements from said color signal, and separating said multiplexed color signal into two color-difference signals, wherein said external signal source comprises a recording means that comprises;

television-signal-system converting means for converting a television signal having interlaced scanning lines into a television signal having line sequential scanning lines, said television-signal-system converting means interpolating picture elements in scanning lines of a brightness signal and a color signal of said interlaced scanning lines to produce a line sequential brightness signal and a line sequential color signal, each of which having reduced number of scanning lines;

subsampling means for carrying out two-dimensional subsampling to said line sequential brightness signal to reduce an amount of data thereof, and for thinning out picture elements of each scanning line of said line sequential color signal and then carrying out two-dimensional subsampling to said thinned line sequential color signal;

a TCI encoder for compressing in time each scanning line of said line sequential brightness signal and of said line sequential color signal outputted from said subsampling means, and for time-division multiplexing said line sequential brightness and color signals; and

D/A converting means for converting said time-division multiplexed signal from said TCI encoder into an analog signal, wherein said television-signal-system converting means comprises;

a line memory for receiving said television signal having interlaced scanning lines, said line memory storing as many picture elements as one scanning line of said high definition television signal;

a field memory for receiving an output of said line memory, said field memory storing as many scanning lines as one field of said television signal having interlaced scanning lines;

a comparator for outputting a picture element having a median value in color density of three picture elements outputted from said television signal having interlaced scanning lines, said line memory, and said field memory; and

a vertical filter for receiving said television signal having interlaced scanning lines, the output of said line memory, and the output of said comparator to produce a television signal having line-sequential scanning lines.

12. A video signal reproducing system for reproducing a video signal, said video signal having been processed by processing means in which said video signal is filtered by a median filter and subsampled by a video signal subsampling means, said reproducing system comprising:

means for receiving the video signal from an external signal source;

a TCI decoder for separating the video signal having line-sequential scanning lines into a brightness signal and a color signal, each of said line-sequential scanning lines being previously compressed in terms of time and time-division multiplexed and having picture elements previously subsampled, said TCI decoder expanding said brightness signal and said color signal relative to time;

first interpolating means for recovering said picture elements from said brightness signal;

second interpolating means for recovering said picture elements from said color signal, and separating said multiplexed color signal into two color-difference signals; and

a horizontal interpolating circuit, coupled to outputs of said second interpolating means, for horizontally interpolating each of said two color-difference signals.