1. COMPRESSION
ANCY MARIAM BABU, VIT UNIVERSITY

2. Compression
 Compression is used to reduce the volume of data
to be transmitted (text , images ,fax)
 To reduce the bandwidth required for transmission
and to reduce storage requirements (video, audio ,
speech) Compression
 Define compression
 Compression can be simple and kind of compression
reduce a text file to 50% of original file.
 How compression is possible…??
- redundancy in video,audio,image file
-human preception properties

3. Compression

4. Classification
 Lossless compression
- for legal and medical
documents,computer programs
-exploit only data redundency
lossy compression
- digital video,images,audio where
some eroors can be correlated.
- both data redundancy and human
preception properties.

5. Video compression
 Video as a sequence of pictures or
frames
 Exploits only spatial redundancy
 High correlation between successive
frames.only small portion of each
frames is involved with any motion
that is taking place
 The combination of actual frame
content and predicted frame content
are used.

6. Video compression techniques
 The examples are:
 Avi : audio video interleave
-used to store audio and video data in file
- formatted as
 JPEG2000: COMPRESSION STANDARD FOR STILL IMAGE
-LOWER LATENCY
- TYPE OF LOSSLESS COMPRESSION
 MPEG2 &MPEG4: VIDEO COMPRESSION STANDARD
- WIDELY USED TO DVD DISCS AND DIGITAL TELEVISON
BROAD CASTING
- USED IN As ENCODER BEFORE TRANSMISSION