Data compression

Comparison of spectrograms of audio in an uncompressed format and several lossy formats. The lossy spectrograms show bandlimiting of higher frequencies, a common technique associated with lossy audio compression.
Solidyne 922: The world's first commercial audio bit compression sound card for PC, 1990
Processing stages of a typical video encoder

Process of encoding information using fewer bits than the original representation.

- Data compression
Comparison of spectrograms of audio in an uncompressed format and several lossy formats. The lossy spectrograms show bandlimiting of higher frequencies, a common technique associated with lossy audio compression.

84 related topics

Alpha

Signal transmission using electronic signal processing. Transducers convert signals from other physical waveforms to electric current or voltage waveforms, which then are processed, transmitted as electromagnetic waves, received and converted by another transducer to final form.

Linear predictive coding

Signal transmission using electronic signal processing. Transducers convert signals from other physical waveforms to electric current or voltage waveforms, which then are processed, transmitted as electromagnetic waves, received and converted by another transducer to final form.

Linear predictive coding (LPC) is a method used mostly in audio signal processing and speech processing for representing the spectral envelope of a digital signal of speech in compressed form, using the information of a linear predictive model.

H.262/MPEG-2 Part 2

Video coding format standardised and jointly maintained by ITU-T Study Group 16 Video Coding Experts Group (VCEG) and ISO/IEC Moving Picture Experts Group (MPEG), and developed with the involvement of many companies.

Video coding format standardised and jointly maintained by ITU-T Study Group 16 Video Coding Experts Group (VCEG) and ISO/IEC Moving Picture Experts Group (MPEG), and developed with the involvement of many companies.

Video compression is practical because the data in pictures is often redundant in space and time.

Partial map of the Internet, with nodes representing IP addresses

Information

Processed, organized and structured data.

Processed, organized and structured data.

Partial map of the Internet, with nodes representing IP addresses
Galactic (including dark) matter distribution in a cubic section of the Universe
Information embedded in an abstract mathematical object with symmetry breaking nucleus
Visual representation of a strange attractor, with converted data of its fractal structure

Data can represent redundant symbols, but approaches information through optimal data compression.

Comparison of spectrograms of audio in an uncompressed format and several lossy formats. The lossy spectrograms show bandlimiting of higher frequencies, a common technique associated with lossy audio compression.

Deblocking filter

Comparison of spectrograms of audio in an uncompressed format and several lossy formats. The lossy spectrograms show bandlimiting of higher frequencies, a common technique associated with lossy audio compression.

A deblocking filter is a video filter applied to decoded compressed video to improve visual quality and prediction performance by smoothing the sharp edges which can form between macroblocks when block coding techniques are used.

Some of the different types of data.

Data communication

Transfer and reception of data in the form of a digital bitstream or a digitized analog signal over a point-to-point or point-to-multipoint communication channel.

Transfer and reception of data in the form of a digital bitstream or a digitized analog signal over a point-to-point or point-to-multipoint communication channel.

Some of the different types of data.

It may also be an analog signal such as a phone call or a video signal, digitized into a bit-stream, for example, using pulse-code modulation or more advanced source coding schemes.

A diagram showing how the user interacts with application software on a typical desktop computer. The application software layer interfaces with the operating system, which in turn communicates with the hardware. The arrows indicate information flow.

Video codec

A diagram showing how the user interacts with application software on a typical desktop computer. The application software layer interfaces with the operating system, which in turn communicates with the hardware. The arrows indicate information flow.

A video codec is software or hardware that compresses and decompresses digital video.

Motion vectors that result from a movement into the z-plane of the image, combined with a lateral movement to the lower-right. This is a visualization of the motion estimation performed in order to compress an MPEG movie.

Motion estimation

Process of determining motion vectors that describe the transformation from one 2D image to another; usually from adjacent frames in a video sequence.

Process of determining motion vectors that describe the transformation from one 2D image to another; usually from adjacent frames in a video sequence.

Motion vectors that result from a movement into the z-plane of the image, combined with a lateral movement to the lower-right. This is a visualization of the motion estimation performed in order to compress an MPEG movie.
Video frames with motion interpolation

As a way of exploiting temporal redundancy, motion estimation and compensation are key parts of video compression.

Example of residential network including VoIP

Voice over IP

Method and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet.

Method and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet.

Example of residential network including VoIP
Asterisk-based PBX for small business

The solution to this problem was linear predictive coding (LPC), a speech coding data compression algorithm that was first proposed by Fumitada Itakura of Nagoya University and Shuzo Saito of Nippon Telegraph and Telephone (NTT) in 1966.

Computer simulation, one of the main cross-computing methodologies.

Deflate

Computer simulation, one of the main cross-computing methodologies.

In computing, Deflate (stylized as DEFLATE) is a lossless data compression file format that uses a combination of LZ77 and Huffman coding.

Digital generation loss induced by rotating a JPEG image 90 degrees (from top to bottom) 0, 100, 200, 500, 900, and 2000 times (without using lossless tools)

Generation loss

Loss of quality between subsequent copies or transcodes of data.

Loss of quality between subsequent copies or transcodes of data.

Digital generation loss induced by rotating a JPEG image 90 degrees (from top to bottom) 0, 100, 200, 500, 900, and 2000 times (without using lossless tools)

Processing a lossily compressed file rather than an original usually results in more loss of quality than generating the same output from an uncompressed original.