A report on 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.

85 related topics with Alpha

Overall

Seismic wavelet

Wavelet

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Wave-like oscillation with an amplitude that begins at zero, increases or decreases, and then returns to zero one or more times.

Wave-like oscillation with an amplitude that begins at zero, increases or decreases, and then returns to zero one or more times.

Seismic wavelet
D4 wavelet
STFT time-frequency atoms (left) and DWT time-scale atoms (right). The time-frequency atoms are four different basis functions used for the STFT (i.e. four separate Fourier transforms required). The time-scale atoms of the DWT achieve small temporal widths for high frequencies and good temporal widths for low frequencies with a single transform basis set.
Signal denoising by wavelet transform thresholding

Generally, an approximation to DWT is used for data compression if a signal is already sampled, and the CWT for signal analysis.

Dolby TrueHD logo as introduced in 2012.

Dolby TrueHD

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Lossless, multi-channel audio codec developed by Dolby Laboratories for home video, used principally in Blu-ray Disc and compatible hardware.

Lossless, multi-channel audio codec developed by Dolby Laboratories for home video, used principally in Blu-ray Disc and compatible hardware.

Dolby TrueHD logo as introduced in 2012.

Dolby's compression mechanism for TrueHD is Meridian Lossless Packing (MLP); prior to Dolby TrueHD, MLP was used for the DVD-Audio format, although the two formats' respective implementations of MLP are not mutually compatible.

Example of residential network including VoIP

Voice over IP

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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.

Sequitur algorithm

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Recursive algorithm developed by Craig Nevill-Manning and Ian H. Witten in 1997 that infers a hierarchical structure (context-free grammar) from a sequence of discrete symbols.

Recursive algorithm developed by Craig Nevill-Manning and Ian H. Witten in 1997 that infers a hierarchical structure (context-free grammar) from a sequence of discrete symbols.

It can be used in data compression software applications.

Deblocking filter

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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.

Uncompressed video

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Uncompressed video is digital video that either has never been compressed or was generated by decompressing previously compressed digital video.

MPEG-4 Part 2

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Video compression format developed by the Moving Picture Experts Group (MPEG).

Video compression format developed by the Moving Picture Experts Group (MPEG).

Most of the video compression schemes standardize the bitstream (and thus the decoder) leaving the encoder design to the individual implementations.

Bandwidth (computing)

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Maximum rate of data transfer across a given path.

Maximum rate of data transfer across a given path.

Digital bandwidth may also refer to: multimedia bit rate or average bitrate after multimedia data compression (source coding), defined as the total amount of data divided by the playback time.

Residual frame

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In video compression algorithms a residual frame is formed by subtracting the reference frame from the desired frame.

H.262/MPEG-2 Part 2

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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.