Method and device for encoding and decoding of symbol sequences wherein each symbol may have one out of three or more possible symbol values

1. A method for compressing a symbol sequence, wherein each symbol has one out of three or more possible symbol values, said method comprising the steps of:

modifying the symbol sequence by replacing each run pair, which contains a first run of symbols of a most frequent symbol value immediately followed by a second run of symbols of a second most frequent symbol value, by a further symbol value being different from the three or more possible symbol values;

generating a binary sequence comprising the replaced run pairs; and

encoding the binary sequence and the modified symbol sequence.

2. A encoder for performing the method of claim 1 .

3. A non-transitory storage medium carrying a symbol sequence compress encoded according to the method of claim 1 .

4. A method for decompressing a compressed symbol sequence, wherein each symbol has one out of three or more possible symbol values, said method comprising the steps of:

decoding a different symbol sequence, said different symbol sequence comprising symbols of a further symbol value being different from the three or more possible symbol values, and decoding a sequence of run pairs comprised in a binary sequence, the number of run pairs in the sequence of run pairs equalling the number of symbols of said further symbol value in the different symbol sequence, wherein a run pair contains a first run of symbols of a symbol value immediately followed by a second run of symbols of a second symbol value; and

replacing, in the different sequence, the symbols of said further symbol value by the run pairs wherein order of the run pairs is maintained.

5. A decoder for performing the method of claim 4 .