27-08-2012, 10:14 AM
Image Compression
Image Compression.pdf (Size: 2.36 MB / Downloads: 207)
Applications of image compression
Televideoconferencing,
Remote sensing (satellite imagery),
Document and medical imaging,
Facsimile transmission (FAX),
Control of remotely piloted vehicles in military, space, and hazardous waste management
Fundamentals
What is dataand hat is information?
Data are the means by which information is conveyed. Various amounts of data may be used to represent the same amount of information
Data redundancy
Coding redundancy
Interpixelredundancy
Psychovisualredundancy
Psychovisualredundancy
Certain information simply has less relative importance than others in normal visual processing –psychovisualredundancy
The elimination of psychovisuallyredundant data results in a loss of quantitative information –called quantization ⇒lossydata compression
E.g., quantization in graylevels
E.g., line interlacing in TV(reduced video scanning rate)
Source encoder model
Mapper
Transform the input data into a format designed to reduce interpixelredundancies in the image (reversible)
Quantizer
Image Compression.pdf (Size: 2.36 MB / Downloads: 207)
Applications of image compression
Televideoconferencing,
Remote sensing (satellite imagery),
Document and medical imaging,
Facsimile transmission (FAX),
Control of remotely piloted vehicles in military, space, and hazardous waste management
Fundamentals
What is dataand hat is information?
Data are the means by which information is conveyed. Various amounts of data may be used to represent the same amount of information
Data redundancy
Coding redundancy
Interpixelredundancy
Psychovisualredundancy
Psychovisualredundancy
Certain information simply has less relative importance than others in normal visual processing –psychovisualredundancy
The elimination of psychovisuallyredundant data results in a loss of quantitative information –called quantization ⇒lossydata compression
E.g., quantization in graylevels
E.g., line interlacing in TV(reduced video scanning rate)
Source encoder model
Mapper
Transform the input data into a format designed to reduce interpixelredundancies in the image (reversible)
Quantizer