Method of and apparatus for encoding and decoding digital video signals by representing orthogonal transform coefficients with respective group values

An apparatus for encoding digital signals representing at least a portion of a video image, comprising:

• means for orthogonally transforming said digital signals to generate a plurality of transformation coefficients;
• means for arranging a portion of said transformation coefficients in a predetermined order;
• means for representing each respective transformation coefficient of said portion with a group value corresponding to one of a set of predefined groups, said set of predefined groups including groups formed of respective ranges of values of zero run lengths representing successive transformation coefficients of said portion having a value of zero and including groups formed of respective ranges of values of said transformation coefficients of said portion having a non-zero value;
• means for providing a data table previously generated as a function of a frequency of occurrence of a combination of said group value and a corresponding prior group value representing the group value of a transformation coefficient that immediately precedes said respective transformation coefficient in said predetermined order;
• and
• means for assigning a respective coding value from said data table to said each respective transformation coefficient as a function of said respective group value and said corresponding prior group value.

A method of recording digital signals representing a video image, comprising the steps of:

• orthogonally transforming said digital signals to generate a plurality of transformation coefficients;
• arranging a portion of said transformation coefficients in a predetermined order;
• representing each respective transformation coefficient of said portion with a group value corresponding to one of a set of predefined groups, said set of predefined groups including groups formed of respective ranges of values of zero run lengths representing successive transformation coefficients of said portion having a value of zero and including groups formed of respective ranges of values of said transformation coefficients of said portion having a non-zero value;
• providing a data table previously generated as a function of a frequency of occurrence of a combination of said group value and a corresponding prior group value representing the group value of a transformation coefficient that immediately precedes said respective transformation coefficient in said predetermined order;
• assigning a respective coding value from said data table to said each respective transformation coefficient as a function of said respective group value and said corresponding prior group value;
• formatting coded signals each representing said respective coding value;
• and
• recording said formatted coded signals on a recording medium.

An apparatus for recording digital signals representing a video image, comprising:

• means for orthogonally transforming said digital signals to generate a plurality of transformation coefficients;
• means for arranging a portion of said transformation coefficients in a predetermined order;
• means for representing each respective transformation coefficient of said portion with a group value corresponding to one of a set of predefined groups, said set of predefined groups including groups formed of respective ranges of values of zero run lengths representing successive transformation coefficients of said portion having a value of zero and including groups formed of respective ranges of values of said transformation coefficients of said portion having a non-zero value;
• means for providing a data table previously generated as a function of a frequency of occurrence of a combination of said group value and a corresponding prior group value representing the group value of a transformation coefficient that immediately precedes said respective transformation coefficient in said predetermined order;
• means for assigning a respective coding value from said data table to said each respective transformation coefficient as a function of said respective group value and said corresponding prior group value;
• means for formatting coded signals each representing said respective coding value;
• and
• means for recording said formatted coded signals on a recording medium.

A method of transmitting digital signals representing a video image, comprising the steps of:

• orthogonally transforming said digital signals to generate a plurality of transformation coefficients;
• arranging a portion of said transformation coefficients in a predetermined order;
• representing each respective transformation coefficient of said portion with a group value corresponding to one of a set of predefined groups, said set of predefined groups including groups formed of respective ranges of values of zero run lengths representing successive transformation coefficients of said portion having a value of zero and including groups formed of respective ranges of values of said transformation coefficients of said portion having a non-zero value;
• providing a data table previously generated as a function of a frequency of occurrence of a combination of said group value and a corresponding prior group value representing the group value of a transformation coefficient that immediately precedes said respective transformation coefficient in said predetermined order;
• assigning a respective coding value from said data table to said each respective transformation coefficient as a function of said respective group value and said corresponding prior group value;
• formatting coded signals each representing said respective coding value;
• and
• transmitting said formatted coded signals.

An apparatus for transmitting digital signals representing a video image, comprising:

• means for orthogonally transforming said digital signals to generate a plurality of transformation coefficients;
• means for arranging a portion of said transformation coefficients in a predetermined order;
• means for representing each respective transformation coefficient of said portion with a group value corresponding to one of a set of predefined groups, said set of predefined groups including groups formed of respective ranges of values of zero run lengths representing successive transformation coefficients of said portion having a value of zero and including groups formed of respective ranges of values of said transformation coefficients of said portion having a non-zero value;
• means for providing a data table previously generated as a function of a frequency of occurrence of a combination of said group value and a corresponding prior group value representing the group value of a transformation coefficient that immediately precedes said respective transformation coefficient in said predetermined order;
• means for assigning a respective coding value from said data table to said each respective transformation coefficient as a function of said respective group value and said corresponding prior group value;
• means for formatting coded signals each representing said respective coding value;
• and
• means for transmitting said formatted coded signals.

A method of decoding digital signals representing a video image, said digital signals being encoded representations of orthogonal transform coefficients. arranged in a predetermined order with each transform coefficient being represented by a group value corresponding to one of a set of predefined groups. said set including groups formed of respective ranges of values of zero run lengths and groups formed of respective ranges Of values of non-zero coefficients., and said digital signals comprising one segment to identify a group and another segment to identify a Huffman code value, said method comprising the steps of:

• recovering segments from said digital signals;
• determining the group value of the encoded digital signal from a prederived data table as a function of the group identifying segment and from a corresponding previously determined group value;
• generating an orthogonal transformation coefficient as a function of said Huffman code identifying segment and said determined group value;
• and
• inverse orthogonally transforming said orthogonal transformation coefficients to generate a decoded digital video signal.

An apparatus for decoding digital signals representing a video image, aid digital signals being encoded representations of orthogonal transform coefficients arranged in predetermined order with each transform coefficient being represented by group value corresponding to one of a set of predefined groups, said set including groups formed of respective ranges of vales of zero run lengths and groups formed of respective ranges of values of non-zero coefficients, and said digital signals comprising one segment to identify a group and another segment to identify a Huffman code value, said apparatus comprising:

• means for recovering segments from said digital signals;
• means for determining the group value of the encoded digital signal from a prederived data table as a function of the group identifying segment and from a corresponding previously determined group value;
• means for generating an orthogonal transformation coefficient as a function of said Huffman code identifying segment and said determined group value and
• means for inverse orthogonally transforming said orthogonal transformation coefficients to generate a decoded digital video signal.

A method of reproducing digital signals recorded on a record medium in the form of formatted signals representing a video image, said digital signals being encoded representations of orthogonal transform coefficients arranged in a predetermined order with each transform coefficient being represented by a group vale corresponding to one of a set of predefined groups, said set including groups formed of respective ranges of values of zero run lengths and groups formed of respective ranges of values of non-zero coefficients, and said digital signals comprising one segment to identify a group and another segment to identify a Huffman code value, said method comprising the steps of:

• reading said formatted signals from said record medium;
• recovering segments from said formatted signals;
• determining the group value of the encoded digit signal from a prederived data table as a function of the group identifying segment and from a corresponding previously determined group value;
• generating an orthogonal transformation coefficient as a function of said Huffman code identifying segment and said determined group value;
• and
• inverse orthogonally transforming said orthogonal transformation coefficients to generate a decoded digital video signal.

Apparatus for reproducing digital signals recorded on a record medium in the form of formatted signals representing a video image, aid digital signals being encoded representations of orthogonal transform coefficients arranged in a predetermined order with each transform coefficient being represented by a group value corresponding to one of a set of predefined groups, said set including groups formed of respective ranges of values of zero run lengths and groups formed of respective ranges of values of non-zero coefficients, and said digital signals comprising one segment to identify a group and another segment to identify a Huffman code value, said apparatus comprising:

• means for reading said formatted signals from said record medium;
• means for recovering segment from said formatted signals;
• means for determining the group value of the encoded digital signal from a prederived data table as a function of the group identifying segment and from a corresponding previously determined group value;
• means for generating an orthogonal transformation coefficient as a function of said Huffman code identifying segment and said determined group value;
• and
• means for inverse orthogonally transforming said orthogonal transformation coefficients to generate a decoded digital video signal.

A method of reproducing digital signals from signals transmitted in the form of formatted signals representing a video image, said digital signals being encoded representations of orthogonal transform coefficients arranged in a predetermined order with each transform coefficient being represented by a group value corresponding to one of a set of predefined groups, said set including groups formed of respective ranges of values of zero run lengths and groups formed of respective ranges of values of non-zero coefficients, and said digital signals comprising one segment to identify a group and another segment to identify Huffman code value, said method comprising the steps of:

• receiving said formatted signals;
• recovering segments from said formatted signals;
• determining the group value of the encoded digital signal from a prederived data table as a function of the group identifying segment and from a corresponding previously determined group value;
• generating an orthogonal transformation coefficient as a function of said Huffman code identifying segment and said determined group value;
• and
• inverse orthogonally transforming said orthogonal transformation coefficients to generate a decoded digital video signal.

Apparatus for reproducing digital signals from signals transmitted in the form of formatted signals representing a video image, said digital signals being encoded representations of orthogonal transform coefficients arranged in a predetermined order with each transform coefficient being represented by a group value corresponding to one of a set of predefined groups, said set including groups formed of respective ranges of values of zero run lengths and groups formed of respective ranges of values of non-zero coefficients, and said digital signals comprising one segment to identify group and another segment to identify a Huffman code value, said apparatus comprising:

• means for receiving said formatted signals;
• means for recovering segments from said formatted signals;
• means for determining the group value of the encoded digital signal from a prederived data table as a function of the group identifying segment and from a corresponding previously determined group value;
• means for generating an orthogonal transformation coefficient as a function of said Huffman code identifying segment and said determined group value;
• and
• means for inverse orthogonally transforming said orthogonal transformation coefficients to generate a decoded digital video signal.

A method of recording and reproducing digital signals representing a video image, comprising the steps of:

• orthogonally transforming said digital signals to generate a plurality of transformation coefficients;
• arranging a portion of said transformation coefficients in a predetermined order;
• representing each respective transformation coefficient of said portion with a group value corresponding to one of a set of predefined groups, said set of predefined groups including groups formed of respective ranges of values of zero run lengths representing successive transformation coefficients of said portion having a value of zero and including groups formed of respective ranges of values of said transformation coefficients of said portion having a non-zero value;
• providing a data table previously generated as a function of a frequency of occurrence of a combination of said group value and a corresponding prior group value representing the group value of a said transformation coefficient that immediately precedes said respective transformation coefficient in said predetermined order;
• assigning a respective coding value from said data table to said each respective transformation coefficient as a function of said respective group value and said corresponding prior group value;
• formatting coded signals each representing said respective coding value;
• recording said formatted signals on a record medium;
• reading said formatted signals from said record medium;
• recovering coding values from said formatted signals;
• determining respective group values from a prederived data table as a function of respective ones of said coding values and from a corresponding previously determined group value, each said group value representing one of a set of predefined groups;
• generating orthogonal transformation coefficients each derived as a function of said respective coding value and said respective group value derived from said respective coding value;
• and
• inverse orthogonally transforming said orthogonal transformation coefficients to generate a decoded digital video signal.

An apparatus for recording and reproducing digital signals representing a video image, comprising:

• means for orthogonally transforming said digital signals to generate a plurality of transformation coefficients;
• means for arranging a portion of said transformation coefficients in a predetermined order;
• means for representing each respective transformation coefficient of said portion with a group value corresponding to one of a set of predefined groups, said set of predefined groups including groups formed of respective ranges of values of zero run lengths representing successive transformation coefficients of said portion having a value of zero and including groups formed of respective ranges of values of said transformation coefficients of said portion having a non-zero value;
• means for providing a data table previously generated as a function of a frequency of occurrence of a combination of said group value and a corresponding prior group value representing the group value of said transformation coefficient that immediately precedes said respective transformation coefficient in said predetermined order;
• means for assigning a respective coding value from said data table to said each respective transformation coefficient as a function of said respective group value and said corresponding prior group value;
• means for formatting coded signals each representing said respective coding value;
• means for recording said formatted signals on a record medium;
• means for reading said formatted signals from said record medium;
• means for recovering coding values from said formatted signals;
• means for determining respective group values from a prederived data table as a function of respective ones of said coding values and from a corresponding previously determined group value, each said group value representing one of a set of predefined groups;
• means for generating orthogonal transformation coefficients each derived as a function of said respective coding value and said respective group value derived from said respective coding value;
• and
• means for inverse orthogonally transforming said orthogonal transformation coefficients to generate a decoded digital video signal.