Huffman Coding

Method

Example Image (3 bits per pixel)

Huffman code table

level count code bits

145 12,153 00 24,306

72 15,772 01 31,544

109 27,371 11 54,742

218 4,431 1000 17,724

36 5,175 1001 20,700

182 6,388 1011 25,552

0 1,174 10100 5,870

255 4.336 10101 21,680

202,128

level	count	code	bits
145	12,153	00	24,306
72	15,772	01	31,544
109	27,371	11	54,742
218	4,431	1000	17,724
36	5,175	1001	20,700
182	6,388	1011	25,552
0	1,174	10100	5,870
255	4.336	10101	21,680
			202,128

Compression ratio

raw 320 * 240 * 3 = 230,400

ratio 230,400/202,128 = 1.140

Other schemes

  packed 28,800  (320*240*3 bits / 8 bits-per-byte)
  GIF    14,290  (includes colormap, original gif 33,674)
  winzip 14,150  (includes directory info overhead)
  gzip   13,845
  jpeg   19,971  (original jpeg 16,866)

Maintained by John Loomis, last updated July 29, 1997