Pre-coding method and apparatus for multiple source or time-shifted single source data and corresponding inverse post-decoding method and apparatus

A pre-coding apparatus to improve data compression performance by removing correlation between a first original data set and a second original data set each having M members, respectively, comprising:

• first means for determining a first difference between one of (1) adjacent members in each of the first and second original data sets to form a first adjacent-delta data set and a second adjacent-delta data set, respectively, and (2) corresponding members of the first original set and the second original sets, respectively, to form a first cross-delta data set;
• and
• second means, responsive to the first means, for determining a second difference between one of (3) corresponding members of the first adjacent-delta data set and the second adjacent-delta data sets, respectively, to form a cross-delta data set, and (4) adjacent members in the first cross-delta data set, to form an adjacent-delta data set;
• wherein if the first difference from the first means is type (1), then the second difference from the second means is type (3);
• and
• wherein if the first difference from the first means is type (2), then the second difference from the second means is type (4);
• output of the second means being a compression-efficiency-enhancing, double-difference data set, for subsequent compression coding.

A method for reconstructing a second original data set, the second original data set having been represented by an adjacent-cross double difference data set due to a double difference calculation upon the second original data set and a first original data set,

• an adjacent-cross double difference data set and an i.sup.th member of the second original data set having been stored, and a first adjacent-delta data set associated with the first original data having been preset,
• the method comprising:
• (a) retrieving the first adjacent-delta data set and the adjacent-cross double difference data set;
• (b) summing, after step (a), corresponding members of the first adjacent-delta data set and the adjacent-cross double difference data set, respectively, to form a second adjacent-delta data set associated with the second original data set;
• (c) retrieving the i.sup.th member of the second original data set;
• (d) setting, after step (c), an initial value equal to the i.sup.th member of the second original data set;
• and
• (e) restoring recursively, after steps (b) and (d), members of the second original data set as a function of the initial value and the second adjacent-delta data set.

An apparatus for reconstructing a second original data set, the second original data set having been represented by an adjacent-cross double difference data set due to a double difference calculation upon the second original data set and a first original data set, the apparatus comprising:

• a first memory for storing an adjacent-cross double difference data set;
• a second memory for storing an i.sup.th member of the second original data set;
• preset means for presetting a first adjacent-delta data set associated with the first original data;
• summation means, responsive to the first memory and the preset means, for summing corresponding members of the first adjacent-delta data set and the adjacent-cross double difference data set, respectively, to form a second adjacent-delta data set associated with the second original data set;
• initialization means, responsive to the second memory, for setting an initial value equal to the i.sup.th member of the second original data set;
• restoration means, responsive to the initialization means and the summation means, for restoring recursively the second original data set as a function of the initial value and the second adjacent-delta data set.

A method for reconstructing a second original data set, the second original data set having been represented by a cross-adjacent double difference data set due to a double difference calculation upon the second original data set and a first original data set,

• an i.sup.th member of a cross-delta data set, a first original data set, and the cross-adjacent double difference data set having been stored,
• the method comprising:
• (a) retrieving the i.sup.th member of the cross-delta data set;
• (b) setting, after step (a), an initial value equal to the i.sup.th member of the cross-delta data set;
• (c) restoring recursively, after step (b), the cross-delta data set as a function of the initial value and the cross-adjacent double difference data set;
• (d) retrieving the first original data set;
• and
• (e) restoring, after steps (c) and (d), members of the second original data set by summing corresponding members of the first original data set and the cross-delta data set, respectively.

An apparatus for reconstructing a second original data set, the second original data set having been represented by a cross-adjacent double difference data set due to a double difference calculation upon the second original data set and a first original data set, the apparatus comprising:

• a first memory storing an i.sup.th member of a cross-delta data set;
• a second memory storing the cross-adjacent double difference data set;
• a third memory storing a first original data set;
• initialization means, responsive to the first memory, for setting an initial value equal to the i.sup.th member of the cross-delta data set;
• restoration means, responsive to the initialization means and the second memory, for restoring recursively the cross-delta data set as a function of the initial value and the cross-adjacent double difference data set;
• summation means, responsive to the restoration means and the third memory, for restoring members of the second original data set by summing corresponding members of the first original data set and the cross-delta data set, respectively.