1. msccomputerscience.com

2. Compression is a key aspect of multimedia It is a technique used in almost all multimedia application Compression is done on source information before its transmission. msccomputerscience.com

3. Why do we need compression? To reduce the volume of information to be transmitted. To reduce the bandwidth required for transmission. msccomputerscience.com

4. Compression principles Source encoders and destination decoders Lossless and lossy compression Entropy encoding Source encoding msccomputerscience.com

5. Source encoders and destination decoders Before Transmitting source information, a compression algorithm is applied Source encoder’s main function is to carry out compression algorithm on source information The destination produces the original source by applying decompression algorithm The main function of destination decoder is to carry out decompression algorithm. msccomputerscience.com

6. Lossless and lossy compression Compression algorithm can eitherbe lossy/lossy In lossless compression algorithm, aim is to reduce amount of source information to be transmitted such a way that when compressed information is decompressed there is no loss of information. Lossless compression is Reversible Used for text file transmission msccomputerscience.com

7. Lossy compression algorithm,is used when there is no need of reproduce exact copy of source information and only approximated version is sufficient Lossy compression is used for image/audio/video transmission Since it is not detectable by the sensitivity of eye msccomputerscience.com

8. Entropy encoding Eentropy encoding is lossless and independent compression of information Entropy encoding is concerned with representation of information Two widely used entropy encoding techniques Runlength encoding Statistical encoding msccomputerscience.com

9. Source encoding This method is used to produce an alternate form of representation,that is compressed form of source (or) a representation suitable for application of compression DCT is an example where we can illustrate,this source encoding msccomputerscience.com