公开(公告)号：US06606039B2

公开(公告)日：2003-08-12

申请号：US09774922

申请日：2001-01-31

申请人： Kenji Hirano ,  Shigeru Sakon

发明人： Kenji Hirano ,  Shigeru Sakon

IPC分类号： H03M740

CPC分类号： H03M7/40 ,  G06T9/007

摘要： A Huffman encoder and a method for Huffman encoding in which a data compression rate can be easily changed and a recording medium having a program for a Huffman encoding process recorded thereon. A quantizer quantizes DCT coefficients output by a DCT device to output quantized DCT coefficients. A comparator judges a quantized DCT coefficient to be an invalid coefficient when the absolute value of the DCT coefficient is equal to or smaller than a threshold and judges the quantized DCT coefficient to be a valid coefficient when the absolute value of the DCT coefficient is greater than the threshold. A run length counter counts the number of consecutive invalid coefficients to output run lengths and outputs valid coefficients. An encoder performs encoding based on the valid coefficients and the run lengths to output encoded data.

摘要翻译： 一种霍夫曼编码器和用于霍夫曼编码的方法，其中数据压缩率可以容易地改变，并且具有记录有用于霍夫曼编码处理的程序的记录介质。 量化器量化DCT设备输出的DCT系数以输出量化的DCT系数。 当DCT系数的绝对值等于或小于阈值时，比较器将量化的DCT系数判断为无效系数，并且当DCT系数的绝对值大于阈值时，将量化的DCT系数判定为有效系数 门槛。 运行长度计数器对连续无效系数的数量进行计数以输出运行长度并输出有效系数。 编码器基于有效系数和运行长度执行编码以输出编码数据。