Picture signal digital processing unit

• US 5,636,316 A
• Filed: 08/01/1994
• Issued: 06/03/1997
• Est. Priority Date: 12/05/1990
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Suga, Atsuo, Sorihashi, Tomohide, Takahashi, Masaru, Nishimura, Keizo, Fujii, Yukio, Oku, Masuo, Ichige, Kenji, Higuchi, Shigemitsu
• Primary Examiner(s): Tran, Thai
• Assistant Examiner(s): NGUYEN, HUY THANH
• Application Number:
  US08/283,685
• Time in Patent Office: 1,037 Days
• Field of Search: 358/335, 358/310, 358/339, 358/336, 358/432, 358/433, 360/32, 360/38.1, 360/48, 348/403, 348/423, 348/404, 348/405
• US Class Current: 386/329
• CPC Class Codes: H04N 9/7973 by dividing the luminance or colour component signal samples or frequency bands among a plurality of recording channels H04N9/804, H04N9/825 take precedence
• CPC Class Codes: H04N 9/8047 using transform coding

Abstract

A digital processing unit for converting a digital picture signal into data by blocks and for correction encoding a variable-length encoded signal. This digital processing unit includes a digital data compressing section for dividing a picture signal into a plurality of number of blocks, and compressingly outputting digital data of this picture signal based on a processing unit of one or a few blocks, a buffer section for sequentially storing the digital data, and an error correction encoding section for sequentially reading the digital data from this buffer section, and structuring an inner code for each inner block structured by this digital data and structuring an outer code for each predetermined unit of inner blocks, to thereby structure two-dimensional error correction code blocks, to output an error correction code signal. Further, the error correction encoding section has the length of the digital data of the picture signal included in the inner code set to be equal to or larger than a mean code length of predetermined compressed blocks.

Claims

1. A digital picture encoding apparatus for encoding a picture signal, said apparatus comprising:

digital data compressing means for dividing a picture signal into blocks and for generating compressed picture data corresponding to said picture signal blocks, including orthogonal transformer means for generating frequency components of picture signal blocks of said picture signal, and variable-length encoding means for encoding said frequency components to provide variable-length compressed picture data; and

error correction encoding means for (a) arranging compressed picture data from said digital data compressing means into two-dimensional arrays of error correction code blocks, each block including (1) compressed picture data having M word columns and L word rows, where M and L are integers, (2) an inner check code for each word row, and (3) an outer check code for each word column, and for (b) providing inner codes each composed of (1) a row of said compressed picture data arranged into said two-dimensional error correction code blocks, (2) said inner check code, (3) a synchronizing code at each head of a row of said error correction code blocks, and (4) an inner header code of information indicating a relationship between data of the main part of said inner code and a display position of said data on a display screen;

wherein the M words forming a row of said two-dimensional array of error correction code blocks have a data length equal to or larger than a mean code length of said variable-length compressed picture data in at least one of said picture signal blocks.

2. A digital picture encoding apparatus for a picture signal according to claim 1, wherein said digital data compressing means further includes fixed-length encoding means for encoding a DC component of said picture signal obtained from said orthogonal transformer means and for sending fixed-length coded data to said error correction encoding means, and said error correction encoding means includes means for applying said fixed-length coded data to a fixed data area of said inner code.

3. A digital picture encoding apparatus for a picture signal, said apparatus comprising:

digital data compressing means for dividing a picture signal into blocks and for generating compressed picture data corresponding to said picture signal blocks, including orthogonal transformer means for generating frequency components of picture signal blocks of said picture signal, and variable-length encoding means for encoding said frequency components to provide variable-length compressed picture data; and

error correction encoding means for (a) arranging compressed picture data from said digital data compressing means into two-dimensional arrays of error blocks, each code block having M word columns and L word rows, where M and L are integers, each block including (1) compressed picture data, (2) an inner check code for each word row, and (3) an outer check code for each word column, and for (b) providing inner codes each composed of (1) a row of said compressed picture data arranged into said two-dimensional error correction code blocks, (2) said inner check code, (3) a synchronizing code at each head of a row of said error correction code blocks, and (4) an inner header code of information indicating a relationship between data of the main part of said inner code and a display position of said data on a display screen;

wherein;

the M words forming a row of said two-dimensional array of error correction code blocks have a data length equal to or larger than a mean code length of said variable-length compressed picture data in at least one of said picture signal blocks,

said digital data compressing means further includes fixed-length encoding means for encoding a DC component of the picture signal, and means for dividing said compressed picture data into first data, composed of fixed-length coded data encoded by said fixed-length encoding means and variable-length coded data representing lower frequency components, and second data composed of variable-length coded data representing higher frequency components, and

said error correction encoding means includes means for inserting said first data of each block into one of said inner codes, so that the beginning of said first data coincides with a predetermined position in said inner code.

4. A digital picture encoding apparatus for a picture signal according to claim 3, further comprising linkage address generating means for generating a linkage address for indicating a boundary between compressed picture data of a block and that of another block in said inner code, and wherein said error correction encoding means includes means for inserting said linkage address into a certain position of said inner code.

5. A digital picture encoding apparatus for a picture signal according to claim 4, wherein said error correction encoding means further includes means for providing outer header information at least indicating a relationship between said second data and its display position.

6. A digital picture encoding/decoding apparatus for compressed picture data, said apparatus comprising:

an encoding section including;

(a) digital data compressing means for dividing a picture signal into blocks and for generating compressed picture data corresponding to said picture signal blocks, including orthogonal transformer means for generating said compressed picture data by generating frequency components of said picture signal blocks, and variable-length encoding means for encoding said frequency components; and

(b) error correction encoding means for (1) arranging said compressed picture data into two-dimensional arrays of error correction code blocks, each code block including compressed picture data having M word columns and L word rows, where M and L are integers, (2) providing an inner check code to each word row and an outer check code to each word column of said error correction code blocks, and (3) structuring inner codes each composed of (i) a row of said compressed picture data arranged into said two-dimensional error correction code blocks, (ii) said inner check code, (iii) a synchronizing code at each head of a row of said error correction code blocks, and (iv) an inner header code of information indicating a relationship between data of the main part of said inner code and a display position of said data on a display screen;

wherein the M words forming a row of said two-dimensional array of error correction code blocks have a data length equal to or larger than a mean code length of said variable-length compressed picture data in at least one of said picture signal blocks; and

a decoding section including;

(a) error correction decoding means for correcting errors in compressed picture data received by said decoding means after compression by said digital data compressing means, by utilizing an inner check code and an outer check code, provided by said error correction encoding means and included in said received compressed picture data; and

(b) digital data expanding means for expanding compressed picture data outputted from said error correction decoding means, including variable-length decoding means for decoding said compressed picture data into frequency components, and orthogonal inverse transformer means for generating a picture signal from said frequency components;

said error correction decoding means including change-over means for selectively outputting either data resulting from error correction by way of said inner check code and outer check code or a signal resulting from error correction by way of only said inner check code.

7. A digital picture encoding/decoding apparatus for compressed picture data, said apparatus comprising:

an encoding section including;

(a) digital data compressing means for dividing a picture signal into blocks and for generating compressed picture data corresponding to said picture signal blocks, including orthogonal transformer means for generating said compressed picture data by generating frequency components of said picture signal blocks, and variable-length encoding means for encoding said frequency components; and

(b) error correction encoding means for (1) arranging said compressed picture data into two-dimensional arrays of error correction code blocks, each code block having M word columns and L word rows, where M and L are integers, (2) providing an inner check code to each word row and an outer check code to each word column of said error correction code blocks, and (3) structuring inner codes each composed of (i) a row of said compressed picture data arranged into said two-dimensional error correction code blocks, (ii) said inner check code, (iii) a synchronizing code at each head of a row of said error correction code blocks, and (iv) an inner header code of information indicating a relationship between data of the main part of said inner code and a display position of said data on a display screen,

wherein;

the M words forming a row of said two-dimensional array of error correction code blocks have a data length equal to or larger than a mean code length of said variable-length compressed picture data in at least one of said picture signal blocks,

said digital data compressing means further includes fixed-length encoding means for encoding a DC component of said picture signal obtained from said orthogonal transformer means, and for sending fixed-length coded data to said error correction encoding means, and

said error correction encoding means includes means for applying said fixed-length coded data to a fixed data area of said inner code; and

a decoding section including;

(a) error correction decoding means for correcting errors in compressed picture data received by said decoding means after compression by said digital data compressing means, by utilizing an inner check code and an outer check code, provided by said error correction encoding means and included in said received compressed picture data; and

(b) digital data expanding means for expanding compressed picture data outputted from said error correction decoding means, including variable-length decoding means for decoding said compressed picture data into frequency components, and orthogonal inverse transformer means for generating a picture signal from said frequency components,

wherein;

said error correction decoding means including change-over means for selectively outputting either data resulting from error correction by way of said inner check code and outer check code or a signal resulting from error correction by way of only said inner check code, and

said digital data expanding means further includes fixed-length decoding means for decoding fixed-length coded data received by said error correction decoding means.

8. A digital picture encoding/decoding apparatus for compressed picture data, said apparatus comprising:

an encoding section including;

(a) digital data compressing means for dividing a picture signal into blocks and for generating compressed picture data corresponding to said picture signal blocks, including orthogonal transformer means for generating said compressed picture data by generating frequency components of said picture signal blocks, and variable-length encoding means for encoding said frequency components; and

(b) error correction encoding means for (1) arranging said compressed picture data into two-dimensional arrays of error correction code blocks, each code block having M word columns and L word rows, where M and L are integers, (2) providing an inner check code to each word row and an outer check code to each word column of said error correction code blocks, and (3) structuring inner codes each composed of (i) a row of said compressed picture data arranged into said two-dimensional error correction code blocks, (ii) said inner check code, (iii) a synchronizing code at each head of a row of said error correction code blocks, and (iv) an inner header code of information indicating a relationship between data of the main part of said inner code and a display position of said data on a display screen,

wherein;

the M words forming a row of said two-dimensional array of error correction code blocks have a data length equal to or larger than a mean code length of said variable-length compressed picture data in at least one of said picture signal blocks,

said digital data compressing means further includes fixed-length encoding means for encoding a DC component of the picture signal, and means for dividing said compressed picture data into first data, composed of fixed-length coded data encoded by said fixed-length encoding means and variable-length coded data representing lower frequency components, and second data, composed of variable-length coded data representing higher frequency components, and

said error correction encoding means includes means for inserting said first data of each block into one of said inner codes, with the beginning of said first data coinciding with a predetermined position in said inner code; and

a decoding section including;

(a) error correction decoding means for correcting errors in compressed picture data received by said decoding means after compression by said digital data compressing means, by utilizing an inner check code and an outer check code, provided by said error correction encoding means and included in said received compressed picture data; and

(b) digital data expanding means for expanding compressed picture data outputted from said error correction decoding means, including variable-length decoding means for decoding said compressed picture data into frequency components, and orthogonal inverse transformer means for generating a picture signal from said frequency components,

wherein;

said error correction decoding means including change-over means for selectively outputting either data resulting from error correction by way of said inner check code and outer check code or a signal resulting from error correction by way of only said inner check code, and

said digital data expanding means further includes combiner means responsive to said first and second data from said error correction decoding means for synthesizing said first data and said second data into one compressed picture data signal composed of full range frequency components.

9. A digital picture encoding/decoding apparatus according to claim 8, wherein:

said error correction encoding means further includes linkage address generating means for generating a linkage address indicating a boundary between compressed picture data of a block and that of another block in said inner code;

said error correction encoding means includes means for inserting said linkage address into a certain position of said inner code; and

said digital data expanding means further includes linkage address detecting means responsive to compressed picture data from said error correction decoding means for detecting a linkage address, and combiner means for regenerating said compressed picture data using said linkage address and outputting regenerated data to said variable-length decoding means.