Research Article
An Adaptive Lossless Data Compression Scheme for Wireless Sensor Networks
Algorithm 1
Pseudo-code of 2-Huffman Table ALEC.
| 2TableALECencoder( di , n , code) | | // encode() is the encode function | | // is the current residue value | | // n is the block size (the number of residue values to be encoded at a time) | | // code is the encoded bitstream of n | | // *denotes concatenation | | // encode block of n using the first Huffman Table of the 2-Huffman Table ALEC Coder | | CALL encode() with block of n and Table A RETURNING | | SET A To | | // compute the size of the encoded bitstream A | | SET size_A TO length(A) | | // encode the same block of n using the second Huffman Table of the 2-Huffman Table ALEC Coder | | CALL encode() with block of n and Table B RETURNING | | SET B To | | // compute the size of the encoded bitstream B | | SET size_B TO length(B) | | // compare size_A and size_B and select the encoded bitstream with the least compressed size | | IF size_A <= size_B THEN | | // generate the table identifier of Table A | | SET ID TO “0” | | // append encoded bitstream A to ID | | SET code TO ID * A | | ELSE | | // generate the table identifier of Table B | | SET ID TO “1” | | // append encoded bitstream B to ID | | SET code TO ID * B | | ENDIF | | RETURN code |
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