| 摘要 |
A size of a 2 N -branch nodeless Huffman tree to be applied is determined depending on which range a total number of character data types X falls within. A size of the 2 N -branch nodeless Huffman tree is a maximum branch number 2 N . An exponent N is an upper limit of compression code length. Therefore, if the size of the 2 N -branch nodeless Huffman tree is determined, the exponent N may be determined depending on the total number of character data types X. For example, when the total number of character data types X is 2 x-2 <X‰¤2 x-1 , the Huffman tree can be constructed if the maximum branch number 2 N is at least 2 x-1 . The size may be minimized by setting N=x-1. When the total number of character data types X is 2 x-1 <X‰¤2 X , the Huffman tree can be constructed if the maximum branch number 2 N is at least 2 x . The size may be minimized by setting N=x. |
