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JPEG2000
JPEG 2000 (JP2) is an image compression standard and coding system. It was developed from 1997 to 2000 by a Joint Photographic Experts Group committee chaired by Touradj Ebrahimi (later the JPEG president), with the intention of superseding their original JPEG standard (created in 1992), which is based on a discrete cosine transform (DCT), with a newly designed, wavelet-based method. The standardized filename extension is .jp2 for ISO/IEC 15444-1 conforming files and .jpx for the extended part-2 specifications, published as ISO/IEC 15444-2. The registered MIME types are defined in RFC 3745. For ISO/IEC 15444-1 it is image/jp2. JPEG 2000 code streams are regions of interest that offer several mechanisms to support spatial random access or region of interest access at varying degrees of granularity. It is possible to store different parts of the same picture using different quality. JPEG 2000 is a compression standard based on a discrete wavelet transform (DWT). The standard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ICER
ICER is a wavelet-based image compression file format used by the NASA Mars rovers. ICER has both lossy and lossless compression modes. The Mars Exploration Rovers ''Spirit'' and ''Opportunity'' both used ICER. Onboard image compression is used extensively to make best use of the downlink resources. The ''Curiosity'' rover supports the use of ICER for its navigation cameras (but all other cameras use other file formats). Most of the MER images are compressed with the ICER image compression software. The remaining MER images that are compressed make use of modified Low Complexity Lossless Compression (LOCO) software, a lossless submode of ICER. ICER is a wavelet-based image compressor that allows for a graceful trade-off between the amount of compression (expressed in terms of compressed data volume in bits/pixel) and the resulting degradation in image quality (distortion). ICER has some similarities to JPEG2000, with respect to select wavelet operations. The development o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motion JPEG 2000
Motion JPEG 2000 (MJ2 or MJP2) is a file format for motion sequences of JPEG 2000 images and associated audio, based on the MP4 and QuickTime format. Filename extensions for Motion JPEG 2000 video files are .mj2 and .mjp2, as defined in RFC 3745. ISO Standards MJ2, first defined by Part 3 of the ISO Standard for JPEG 2000 ISO/IEC 15444 in November 2001(ISO/IEC 15444-3:2002) as a standalone document, has later been defined b additional profiles for archiving applications, and b [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Image Compression
Image compression is a type of data compression applied to digital images, to reduce their cost for storage or transmission. Algorithms may take advantage of visual perception and the statistical properties of image data to provide superior results compared with generic data compression methods which are used for other digital data. Lossy and lossless image compression Image compression may be lossy or lossless. Lossless compression is preferred for archival purposes and often for medical imaging, technical drawings, clip art, or comics. Lossy compression methods, especially when used at low bit rates, introduce compression artifacts. Lossy methods are especially suitable for natural images such as photographs in applications where minor (sometimes imperceptible) loss of fidelity is acceptable to achieve a substantial reduction in bit rate. Lossy compression that produces negligible differences may be called visually lossless. Methods for lossy compression: * Transform ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video Compression
In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compression reduces bits by identifying and eliminating statistical redundancy. No information is lost in lossless compression. Lossy compression reduces bits by removing unnecessary or less important information. Typically, a device that performs data compression is referred to as an encoder, and one that performs the reversal of the process (decompression) as a decoder. The process of reducing the size of a data file is often referred to as data compression. In the context of data transmission, it is called source coding; encoding done at the source of the data before it is stored or transmitted. Source coding should not be confused with channel coding, for error detection and correction or line coding, the means for mapping data onto a signal. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Cinema
Digital cinema refers to adoption of digital technology within the film industry to distribute or project motion pictures as opposed to the historical use of reels of motion picture film, such as 35 mm film. Whereas film reels have to be shipped to movie theaters, a digital movie can be distributed to cinemas in a number of ways: over the Internet or dedicated satellite links, or by sending hard drives or optical discs such as Blu-ray discs. Digital movies are projected using a digital video projector instead of a film projector, are shot using digital movie cameras and edited using a non-linear editing system (NLE). The NLE is often a video editing application installed in one or more computers that may be networked to access the original footage from a remote server, share or gain access to computing resources for rendering the final video, and to allow several editors to work on the same timeline or project. Alternatively a digital movie could be a film reel that has b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Cinema
Digital cinema refers to adoption of digital technology within the film industry to distribute or project motion pictures as opposed to the historical use of reels of motion picture film, such as 35 mm film. Whereas film reels have to be shipped to movie theaters, a digital movie can be distributed to cinemas in a number of ways: over the Internet or dedicated satellite links, or by sending hard drives or optical discs such as Blu-ray discs. Digital movies are projected using a digital video projector instead of a film projector, are shot using digital movie cameras and edited using a non-linear editing system (NLE). The NLE is often a video editing application installed in one or more computers that may be networked to access the original footage from a remote server, share or gain access to computing resources for rendering the final video, and to allow several editors to work on the same timeline or project. Alternatively a digital movie could be a film reel that has b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wavelet
A wavelet is a wave-like oscillation with an amplitude that begins at zero, increases or decreases, and then returns to zero one or more times. Wavelets are termed a "brief oscillation". A taxonomy of wavelets has been established, based on the number and direction of its pulses. Wavelets are imbued with specific properties that make them useful for signal processing. For example, a wavelet could be created to have a frequency of Middle C and a short duration of roughly one tenth of a second. If this wavelet were to be convolved with a signal created from the recording of a melody, then the resulting signal would be useful for determining when the Middle C note appeared in the song. Mathematically, a wavelet correlates with a signal if a portion of the signal is similar. Correlation is at the core of many practical wavelet applications. As a mathematical tool, wavelets can be used to extract information from many different kinds of data, including but not limited to au ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video Coding Standard
A video coding format (or sometimes video compression format) is a content representation format for storage or transmission of digital video content (such as in a data file or bitstream). It typically uses a standardized video compression algorithm, most commonly based on discrete cosine transform (DCT) coding and motion compensation. A specific software, firmware, or hardware implementation capable of compression or decompression to/from a specific video coding format is called a video codec. Some video coding formats are documented by a detailed technical specification document known as a video coding specification. Some such specifications are written and approved by standardization organizations as technical standards, and are thus known as a video coding standard. The term 'standard' is also sometimes used for ''de facto'' standards as well as formal standards. Video content encoded using a particular video coding format is normally bundled with an audio stream (encoded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Cinema Package
A Digital Cinema Package (DCP) is a collection of digital files used to store and convey digital cinema (DC) audio, image, and data streams. The term was popularized by Digital Cinema Initiatives, LLC in its original recommendation for packaging DC contents. However, the industry tends to apply the term to the structure more formally known as the composition. ("You PLAY a composition, You do NOT play a Digital Cinema Package".) A DCP is a “packing crate” for compositions, a hierarchical file structure that represents a title version. The DCP may carry a partial composition (e.g. not a complete set of files), a single complete composition, or multiple and complete compositions. The composition consists of a Composition Playlist (in XML format) that defines the playback sequence of a set of Track Files. Track Files carry the essence, which is wrapped using Material eXchange Format (MXF). Two track files at a minimum must be present in every composition (see SMPTE ST429-2 D-Ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JPEG
JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality. Since its introduction in 1992, JPEG has been the most widely used image compression standard in the world, and the most widely used digital image format, with several billion JPEG images produced every day as of 2015. The term "JPEG" is an acronym for the Joint Photographic Experts Group, which created the standard in 1992. JPEG was largely responsible for the proliferation of digital images and digital photos across the Internet, and later social media. JPEG compression is used in a number of image file formats. JPEG/ Exif is the most common image format used by digital cameras and other photographic image capture devices; along with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ringing Artifacts
In signal processing, particularly digital image processing, ringing artifacts are artifacts that appear as spurious signals near sharp transitions in a signal. Visually, they appear as bands or "ghosts" near edges; audibly, they appear as "echos" near transients, particularly sounds from percussion instruments; most noticeable are the pre-echos. The term "ringing" is because the output signal oscillates at a fading rate around a sharp transition in the input, similar to a bell after being struck. As with other artifacts, their minimization is a criterion in filter design. Introduction The main cause of ringing artifacts is due to a signal being bandlimited (specifically, not having high frequencies) or passed through a low-pass filter; this is the frequency domain description. In terms of the time domain, the cause of this type of ringing is the ripples in the sinc function,, section I.6, Enhancement: Frequency Domain Techniquesp. 16/ref> which is the impulse respo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joint Photographic Experts Group
The Joint Photographic Experts Group (JPEG) is the joint committee between ISO/IEC JTC 1/SC 29 and ITU-T Study Group 16 that created and maintains the JPEG, JPEG 2000, JPEG XR, JPEG XT, JPEG XS, JPEG XL, and related digital image standards. It also has the responsibility for maintenance of the JBIG and JBIG2 standards that were developed by the former Joint Bi-level Image Experts Group. Within ISO/IEC JTC 1, JPEG is Working Group 1 (WG 1) of Subcommittee 29 (SC 29) and has the formal title ''JPEG Coding of digital representations of images'', where it is one of eight working groups in SC 29. In the ITU-T (formerly called the CCITT), its work falls in the domain of the ITU-T Visual Coding Experts Group (VCEG), which is Question 6 of Study Group 16. JPEG has typically held meetings three or four times annually in North America, Asia and Europe (with meetings held virtually during the COVID-19 pandemic). The chairman of JPEG (termed its ''Convenor'' in ISO/IEC terminology) i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
