Repetitions as Control Characters

Another option to reduce the effort for coding of control characters within original data is to interpret two identical symbols following each other as an identificator for a run.

     uncoded   coded
         cde   cde
        cdde   cdd0e
       cddde   cdd1e
      cdddde   cdd2e
     cddddde   cdd3e

According to this method the compression will always be deteriorated whenever a pair of two identical symbols appear. This is frequently the case for pure text data (tt, ss, nn, etc.) or a certain type of graphic data (pattern). Problems due to a disadvantageous selection will be advoided effectively.

Wether this procedure will be applied in practice is not well known.

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