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LOSSLESS COMPRESSION ALGORITHMS
By
Marwa
BASICS OF INFORMATION THEORY
RUN-LENGTH CODING
VARIABLE-LENGTH CODING
SHANNONFANO ALGORITHM
HUFFMAN CODING
EXTENDED HUFFMAN CODING
EXAMPLE
DICTIONARY-BASED CODING
LZW ALGORITHM DETAILS
ARITHMETIC CODING
BASIC ARITHMETIC CODING ALGORITHM
Outline
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
RUN-LENGTH CODING
Memoryless Source: an information source that is indepen-
dently distributed. Namely, the value of the current symbol
does not depend on the values of the previously appeared
symbols.
Instead of assuming memoryless source, Run-Length Coding
(RLC) exploits memory present in the information source.
Rationale for RLC: if the information source has the prop-
erty that symbols tend to form continuous groups, then such
symbol and the length of the group can be coded.
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
EXTENDED HUFFMAN EXAMPLE
As an explicit example of the power of Extended Huffman
Coding, let us construct
a binary Huffman code for a source S with just three symbols A,
B, and C, having
probabilities 0.6, 0.3, and 0.1, respectively. That is, here we have
n = 3.
We are interested in what the average codeword length is, in bits
per symbol. To
start with, in comparison let us first look at the value of the
entropy of this source,
and the bitrate given by Huffman coding for single symbols, not
blocks.
EXTENDED HUFFMAN EXAMPLE
EXTENDED HUFFMAN EXAMPLE
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
Multimedia lossless compression algorithms
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Multimedia lossless compression algorithms

  • 2. BASICS OF INFORMATION THEORY RUN-LENGTH CODING VARIABLE-LENGTH CODING SHANNONFANO ALGORITHM HUFFMAN CODING EXTENDED HUFFMAN CODING EXAMPLE DICTIONARY-BASED CODING LZW ALGORITHM DETAILS ARITHMETIC CODING BASIC ARITHMETIC CODING ALGORITHM Outline
  • 8. RUN-LENGTH CODING Memoryless Source: an information source that is indepen- dently distributed. Namely, the value of the current symbol does not depend on the values of the previously appeared symbols. Instead of assuming memoryless source, Run-Length Coding (RLC) exploits memory present in the information source. Rationale for RLC: if the information source has the prop- erty that symbols tend to form continuous groups, then such symbol and the length of the group can be coded.
  • 19. EXTENDED HUFFMAN EXAMPLE As an explicit example of the power of Extended Huffman Coding, let us construct a binary Huffman code for a source S with just three symbols A, B, and C, having probabilities 0.6, 0.3, and 0.1, respectively. That is, here we have n = 3. We are interested in what the average codeword length is, in bits per symbol. To start with, in comparison let us first look at the value of the entropy of this source, and the bitrate given by Huffman coding for single symbols, not blocks.