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79-403: XMP standardizes a data model, a serialization format and core properties for the definition and processing of extensible metadata. It also provides guidelines for embedding XMP information into popular image, video and document file formats, such as JPEG and PDF , without breaking their readability by applications that do not support XMP. Therefore, the non-XMP metadata have to be reconciled with

158-451: A lossless graphics format such as TIFF , GIF , PNG , or a raw image format . The JPEG standard includes a lossless coding mode, but that mode is not supported in most products. As the typical use of JPEG is a lossy compression method, which reduces the image fidelity, it is inappropriate for exact reproduction of imaging data (such as some scientific and medical imaging applications and certain technical image processing work). JPEG

237-450: A 2004 talk on IT Conversations discussed the benefits of allowing easier access to DjVu files. The DjVu library distributed as part of the open-source package DjVuLibre has become the reference implementation for the DjVu format. DjVuLibre has been maintained and updated by the original developers of DjVu since 2002. The DjVu file format specification has gone through a number of revisions,

316-521: A DCT-based image compression algorithm, and would later be a cause of controversy in 2002 (see Patent controversy below). However, the JPEG specification did cite two earlier research papers by Wen-Hsiung Chen, published in 1977 and 1984. "JPEG" stands for Joint Photographic Experts Group , the name of the committee that created the JPEG standard and other still picture coding standards. The "Joint" stood for ISO TC97 WG8 and CCITT SGVIII. Founded in 1986,

395-468: A JPEG of cover art in the ID3v2 tag. Many JPEG files embed an ICC color profile ( color space ). Commonly used color profiles include sRGB and Adobe RGB . Because these color spaces use a non-linear transformation, the dynamic range of an 8-bit JPEG file is about 11 stops ; see gamma curve . If the image doesn't specify color profile information ( untagged ), the color space is assumed to be sRGB for

474-545: A MIME type of "image/pjpeg" when uploading JPEG images. JPEG files usually have a filename extension of "jpg" or "jpeg". JPEG/JFIF supports a maximum image size of 65,535×65,535 pixels, hence up to 4 gigapixels for an aspect ratio of 1:1. In 2000, the JPEG group introduced a format intended to be a successor, JPEG 2000 , but it was unable to replace the original JPEG as the dominant image standard. The original JPEG specification published in 1992 implements processes from various earlier research papers and patents cited by

553-563: A PDF. The next version of the Adobe Creative Suite (CS2) included these custom panels as part of its default set. The Windows Photo Gallery , released with Windows Vista , offers support for the XMP standard, the first time Microsoft has released metadata compatibility beyond Exif . JPEG This is an accepted version of this page JPEG ( / ˈ dʒ eɪ p ɛ ɡ / JAY -peg , short for Joint Photographic Experts Group )

632-404: A block boundary for all channels (because the edge would end up on top or left, where – as aforementioned – a block boundary is obligatory). Rotations where the image is not a multiple of 8 or 16, which value depends upon the chroma subsampling, are not lossless. Rotating such an image causes the blocks to be recomputed which results in loss of quality. When using lossless cropping, if

711-399: A document as a whole (the "main" metadata), but can also describe parts of a document, such as pages or included images. This architecture makes it possible to retain authorship and rights information about, for example, images included in a published document. Similarly, it permits documents created from several smaller documents to retain the original metadata associated with the parts. This

790-670: A fourth lawsuit on January 8, 2008, in South Florida against the Boca Raton Resort & Club . A fifth lawsuit was filed against Global Patent Holdings in Nevada. That lawsuit was filed by Zappos.com , Inc., which was allegedly threatened by Global Patent Holdings, and sought a judicial declaration that the '341 patent is invalid and not infringed. Global Patent Holdings had also used the '341 patent to sue or threaten outspoken critics of broad software patents, including Gregory Aharonian and

869-411: A lossy form of compression based on the discrete cosine transform (DCT) . This mathematical operation converts each frame/field of the video source from the spatial (2D) domain into the frequency domain (a.k.a. transform domain). A perceptual model based loosely on the human psychovisual system discards high-frequency information, i.e. sharp transitions in intensity, and color hue. In the transform domain,

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948-642: A minimum of space, so that they can be made available on the web . DjVu has been promoted as providing smaller files than PDF for most scanned documents. The DjVu developers report that color magazine pages compress to 40–70 kB, black-and-white technical papers compress to 15–40 kB, and ancient manuscripts compress to around 100 kB; a satisfactory JPEG image typically requires 500 kB. Like PDF, DjVu can contain an OCR text layer, making it easy to perform copy and paste and text search operations. Free creators, manipulators, converters, web browser plug-ins, and desktop viewers are available. DjVu

1027-483: A namespace for the Dublin Core Metadata Element Set). Custom namespaces can be used to extend the data model. An instance of the XMP data model is called an XMP packet. Adding properties to a packet does not affect existing properties. Software to add or modify properties in an XMP packet should leave properties that are unknown to it untouched. For example, it is useful for recording the history of

1106-600: A public patent license for the XMP.As of November 2016, Adobe continues to distribute these documents under the XMP Specification Public Patent License . XMP was first introduced by Adobe in April 2001 as part of the Adobe Acrobat 5.0 software product. Before that, it was called XAP (Extensible Authoring and Publishing) as internal code name. On June 21, 2004, Adobe announced its collaboration with

1185-475: A resource as it passes through multiple processing steps, from being photographed, scanned , or authored as text, through photo editing steps (such as cropping or color adjustment), to assemble into a final document. XMP allows each software program or device along the workflow to add its own information to a digital resource, which carries its metadata along. The prerequisite is that all involved editors either actively support XMP, or at least do not delete it from

1264-399: A single image into many different images, then compresses them separately. To create a DjVu file, the initial image is first separated into three images: a background image, a foreground image, and a mask image. The background and foreground images are typically lower-resolution color images (e.g., 100 dpi); the mask image is a high-resolution bilevel image (e.g., 300 dpi) and is typically where

1343-521: A slow connection, allowing a reasonable preview after receiving only a portion of the data. However, support for progressive JPEGs is not universal. When progressive JPEGs are received by programs that do not support them (such as versions of Internet Explorer before Windows 7 ) the software displays the image only after it has been completely downloaded. There are also many medical imaging, traffic and camera applications that create and process 12-bit JPEG images both grayscale and color. 12-bit JPEG format

1422-767: A typical edited JPEG file, XMP information is typically included alongside Exif and IPTC Information Interchange Model data. For more details, the XMP Specification, Part 3 Storage in Files listed below has details on embedding in specific file formats. The XMP Toolkit implements metadata handling in two libraries: Adobe provides the XMP Toolkit free of charge under a BSD license . The Toolkit includes specification and usage documents (PDFs), API documentation ( doxygen / javadoc ), C++ source code (XMPCore and XMPFiles) and Java source code (currently only XMPCore). XMPFiles

1501-431: Is a computer file format designed primarily to store scanned documents , especially those containing a combination of text, line drawings, indexed color images , and photographs. It uses technologies such as image layer separation of text and background/images, progressive loading , arithmetic coding , and lossy compression for bitonal ( monochrome ) images. This allows high-quality, readable images to be stored in

1580-439: 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

1659-540: Is a minimal file format which enables JPEG bitstreams to be exchanged between a wide variety of platforms and applications. This minimal format does not include any of the advanced features found in the TIFF JPEG specification or any application specific file format. Nor should it, for the only purpose of this simplified format is to allow the exchange of JPEG compressed images. Image files that employ JPEG compression are commonly called "JPEG files", and are stored in variants of

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1738-493: Is also not well suited to files that will undergo multiple edits, as some image quality is lost each time the image is recompressed, particularly if the image is cropped or shifted, or if encoding parameters are changed – see digital generation loss for details. To prevent image information loss during sequential and repetitive editing, the first edit can be saved in a lossless format, subsequently edited in that format, then finally published as JPEG for distribution. JPEG uses

1817-704: Is an open file format with patents. The file format specification is published, as well as source code for the reference library. The original authors distribute an open-source implementation named " DjVuLibre " under the GNU General Public License and a patent grant. The rights to the commercial development of the encoding software have been transferred to different companies over the years, including AT&T Corporation , LizardTech , Celartem and Cuminas . Patents typically have an expiry term of about 20 years. Celartem acquired LizardTech and Extensis . The selection of downloadable DjVu viewers

1896-768: Is an example XML document for serialized XMP metadata in a JPEG photo: This metadata describes various properties of the image like the creator tool, image dimension or a face region within the image. Embedding metadata in files allows easy sharing and transfer of files across products, vendors, platforms, without metadata getting lost. Embedding avoids a multitude of problems coming from proprietary vendor-specific metadata databases. XMP can be used in several file formats such as PDF , JPEG , JPEG 2000 , JPEG XR , JPEG XL , GIF , PNG , WebP , HTML , TIFF , Adobe Illustrator , PSD , MP3 , MP4 , Audio Video Interleave , WAV , RF64 , Audio Interchange File Format , PostScript , Encapsulated PostScript , and proposed for DjVu . In

1975-508: Is currently available as a C++/Java implementation in Windows, Mac OS, Unix / Linux . The mainstream IPTC Information Interchange Model editing tools also support editing of XMP data. XMP is a registered trademark of Adobe Systems Incorporated. The XMP specification became an ISO standard and is not proprietary anymore. Initially, Adobe released source code for the XMP SDK under a license called

2054-526: Is included in an Extended part of the JPEG specification. The libjpeg codec supports 12-bit JPEG and there even exists a high-performance version. Several alterations to a JPEG image can be performed losslessly (that is, without recompression and the associated quality loss) as long as the image size is a multiple of 1 MCU block (Minimum Coded Unit) (usually 16 pixels in both directions, for 4:2:0 chroma subsampling ). Utilities that implement this include: Blocks can be rotated in 90-degree increments, flipped in

2133-530: Is infringed by the downloading of JPEG images on either a website or through e-mail. If not invalidated, this patent could apply to any website that displays JPEG images. The patent was under reexamination by the U.S. Patent and Trademark Office from 2000 to 2007; in July 2007, the Patent Office revoked all of the original claims of the patent but found that an additional claim proposed by Global Patent Holdings (claim 17)

2212-403: Is lost and cannot be restored, possibly affecting image quality. There is an optional lossless mode defined in the JPEG standard. However, this mode is not widely supported in products. There is also an interlaced progressive JPEG format, in which data is compressed in multiple passes of progressively higher detail. This is ideal for large images that will be displayed while downloading over

2291-400: Is possible to select and copy text. Since JB2 (also called DjVuBitonal) is a variation on JBIG2, working on the same principles, both compression methods have the same problems when performing lossy compression. In 2013 it emerged that Xerox photocopiers and scanners had been substituting digits for similar looking ones, for example replacing a 6 with an 8. A DjVu document has been spotted in

2370-418: Is preceded by a 4-byte AT&T magic number . Following is a single FORM chunk with a secondary identifier of either DJVU or DJVM for a single-page or a multi-page document, respectively. All the chunks can be contained in a single file in the case of the so called bundled documents, or can be contained in several files: one file for every page plus some files with shared chunks. DjVu divides

2449-432: Is supported by a number of multi-format document viewers and e-book reader software on Linux ( Okular , Evince , Zathura ), Windows ( Okular , SumatraPDF ), and Android ( Document Viewer , FBReader, EBookDroid, PocketBook). The DjVu technology was originally developed by Yann LeCun , Léon Bottou , Patrick Haffner , Paul G. Howard , Patrice Simard , and Yoshua Bengio at AT&T Labs from 1996 to 2001. Prior to

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2528-479: Is the most common image format used by digital cameras and other photographic image capture devices; along with JPEG/ JFIF , it is the most common format for storing and transmitting photographic images on the World Wide Web . These format variations are often not distinguished and are simply called JPEG. The MIME media type for JPEG is "image/jpeg", except in older Internet Explorer versions, which provide

2607-583: Is wider on Linux distributions than it is on Windows or macOS. Additionally, the format is rarely supported by proprietary scanning software. In 2002, the DjVu file format was chosen by the Internet Archive as a format in which its Million Book Project provides scanned public-domain books online (along with TIFF and PDF). In February 2016, the Internet Archive announced that DjVu would no longer be used for new uploads, among other reasons citing

2686-627: The ADOBE SYSTEMS INCORPORATED ;— OPEN SOURCE LICENSE . The compatibility of this license with the GNU General Public License has been questioned. The license is not listed on the list maintained by the Open Source Initiative and is different from the licenses for most of their open source software. On May 14, 2007, Adobe released the XMP Toolkit SDK under a standard BSD license. On August 28, 2008, Adobe posted

2765-619: The CCITT (now ITU-T ) and Joint Photographic Experts Group. The JPEG specification cites patents from several companies. The following patents provided the basis for its arithmetic coding algorithm. The JPEG specification also cites three other patents from IBM. Other companies cited as patent holders include AT&T (two patents) and Canon Inc. Absent from the list is U.S. patent 4,698,672 , filed by Compression Labs ' Wen-Hsiung Chen and Daniel J. Klenke in October 1986. The patent describes

2844-537: The Dublin Core Metadata Initiative , which include things like title, description, creator, and so on. The standard is designed to be extensible, allowing users to add their own custom types of metadata into the XMP data. XMP generally does not allow binary data types to be embedded. This means that any binary data one wants to carry in XMP, such as thumbnail images, must be encoded in some XML-friendly format, such as Base64 . XMP metadata can describe

2923-500: The International Press Telecommunications Council . In July 2004, a working group led by Adobe Systems ' Gunar Penikis and IPTC's Michael Steidl was set up, and volunteers were recruited from AFP (Agence France-Presse) , Associated Press , ControlledVocabulary.com, IDEAlliance, Mainichi Shimbun , Reuters , and others, to develop the new schema. The "IPTC Core Schema for XMP" version 1.0 specification

3002-488: The 2000s, with the growth of the World Wide Web and before widespread adoption of broadband , DjVu was often adopted by digital libraries as their format of choice, thanks to its integration with software like Greenstone and the Internet Archive , browser plugins which allowed advanced online browsing, smaller file size for comparable quality of book scans and other image-heavy documents and support for embedding and searching full text from OCR . Some features such as

3081-504: The ITU-T side, ITU-T SG16 is the respective body. The original JPEG Group was organized in 1986, issuing the first JPEG standard in 1992, which was approved in September 1992 as ITU-T Recommendation T.81 and, in 1994, as ISO / IEC 10918-1 . The JPEG standard specifies the codec , which defines how an image is compressed into a stream of bytes and decompressed back into an image, but not

3160-647: The JIF image format. Most image capture devices (such as digital cameras) that output JPEG are actually creating files in the Exif format, the format that the camera industry has standardized on for metadata interchange. On the other hand, since the Exif standard does not allow color profiles, most image editing software stores JPEG in JFIF format, and includes the APP1 segment from the Exif file to include

3239-498: The JPEG image compression standard infringes the '056 patent and has sued large numbers of websites, retailers, camera and device manufacturers and resellers. The patent was originally owned and assigned to General Electric. The patent expired in December 2007, but Princeton has sued large numbers of companies for "past infringement" of this patent. (Under U.S. patent laws, a patent owner can sue for "past infringement" up to six years before

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3318-489: The JPEG standard. The JPEG committee has as one of its explicit goals that their standards (in particular their baseline methods) be implementable without payment of license fees, and they have secured appropriate license rights for their JPEG 2000 standard from over 20 large organizations. Beginning in August 2007, another company, Global Patent Holdings, LLC claimed that its patent ( U.S. patent 5,253,341 ) issued in 1993,

3397-683: The XMP properties. Although metadata can alternatively be stored in a sidecar file , embedding metadata avoids problems that occur when metadata is stored separately. The XMP data model, serialization format and core properties is published by the International Organization for Standardization as ISO 16684-1:2012 standard. The defined XMP data model can be used to store any set of metadata properties. These can be simple name/value pairs, structured values or lists of values. The data can be nested as well. The XMP standard also defines particular namespaces for defined sets of core properties (e.g.

3476-399: The amount of data used for an image is important for responsive presentation, JPEG's compression benefits make JPEG popular. JPEG/ Exif is also the most common format saved by digital cameras. However, JPEG is not well suited for line drawings and other textual or iconic graphics, where the sharp contrasts between adjacent pixels can cause noticeable artifacts. Such images are better saved in

3555-445: The anonymous operator of a website blog known as the " Patent Troll Tracker ." On December 21, 2007, patent lawyer Vernon Francissen of Chicago asked the U.S. Patent and Trademark Office to reexamine the sole remaining claim of the '341 patent on the basis of new prior art. On March 5, 2008, the U.S. Patent and Trademark Office agreed to reexamine the '341 patent, finding that the new prior art raised substantial new questions regarding

3634-477: The bottom or right side of the crop region is not on a block boundary, then the rest of the data from the partially used blocks will still be present in the cropped file and can be recovered. It is also possible to transform between baseline and progressive formats without any loss of quality, since the only difference is the order in which the coefficients are placed in the file. Furthermore, several JPEG images can be losslessly joined, as long as they were saved with

3713-470: The burden of rendering the document on the reader, whereas DjVu places that burden on the creator. During a number of years, significantly overlapping with the period when DjVu was being developed, there were no PDF viewers for free operating systems—a particular stumbling block was the rendering of vectorised fonts, which are essential for combining small file size with high resolution in PDF. Since displaying DjVu

3792-417: The compressed data, optional 0xFF fill bytes may precede the marker"). Within the entropy-coded data, after any 0xFF byte, a 0x00 byte is inserted by the encoder before the next byte, so that there does not appear to be a marker where none is intended, preventing framing errors. Decoders must skip this 0x00 byte. This technique, called byte stuffing (see JPEG specification section F.1.2.3), is only applied to

3871-534: The entropy-coded data, not to marker payload data. Note however that entropy-coded data has a few markers of its own; specifically the Reset markers (0xD0 through 0xD7), which are used to isolate independent chunks of entropy-coded data to allow parallel decoding, and encoders are free to insert these Reset markers at regular intervals (although not all encoders do this). There are other Start Of Frame markers that introduce other kinds of JPEG encodings. DjVu DjVu

3950-495: The file format used to contain that stream. The Exif and JFIF standards define the commonly used file formats for interchange of JPEG-compressed images. JPEG standards are formally named as Information technology – Digital compression and coding of continuous-tone still images . ISO/IEC 10918 consists of the following parts: Ecma International TR /98 specifies the JPEG File Interchange Format (JFIF);

4029-451: The file that were left for future use in the JIF standard and are not read by it, these standards add specific metadata. Thus, in some ways, JFIF is a cut-down version of the JIF standard in that it specifies certain constraints (such as not allowing all the different encoding modes), while in other ways, it is an extension of JIF due to the added metadata. The documentation for the original JFIF standard states: JPEG File Interchange Format

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4108-618: The filing of a lawsuit, so Princeton could theoretically have continued suing companies until December 2013.) As of March 2013, Princeton had suits pending in New York and Delaware against more than 55 companies. General Electric's involvement in the suit is unknown, although court records indicate that it assigned the patent to Princeton in 2009 and retains certain rights in the patent. The JPEG compression algorithm operates at its best on photographs and paintings of realistic scenes with smooth variations of tone and color. For web usage, where reducing

4187-505: The first "Office Action" of the second reexamination, finding the claim invalid based on nineteen separate grounds. On Nov. 24, 2009, a Reexamination Certificate was issued cancelling all claims. Beginning in 2011 and continuing as of early 2013, an entity known as Princeton Digital Image Corporation, based in Eastern Texas, began suing large numbers of companies for alleged infringement of U.S. patent 4,813,056 . Princeton claims that

4266-575: The first edition was published in June 2009. In 2002, Forgent Networks asserted that it owned and would enforce patent rights on the JPEG technology, arising from a patent that had been filed on October 27, 1986, and granted on October 6, 1987: U.S. patent 4,698,672 by Compression Labs ' Wen-Hsiung Chen and Daniel J. Klenke. While Forgent did not own Compression Labs at the time, Chen later sold Compression Labs to Forgent, before Chen went on to work for Cisco . This led to Forgent acquiring ownership over

4345-432: The following Exif segment, being less strict about requiring it to appear first. The most common filename extensions for files employing JPEG compression are .jpg and .jpeg , though .jpe , .jfif and .jif are also used. It is also possible for JPEG data to be embedded in other file types – TIFF encoded files often embed a JPEG image as a thumbnail of the main image; and MP3 files can contain

4424-448: The group developed the JPEG standard during the late 1980s. The group published the JPEG standard in 1992. In 1987, ISO TC 97 became ISO/IEC JTC 1 and, in 1992, CCITT became ITU-T. Currently on the JTC1 side, JPEG is one of two sub-groups of ISO / IEC Joint Technical Committee 1 , Subcommittee 29, Working Group 1 ( ISO/IEC JTC 1/SC 29 /WG 1) – titled as Coding of still pictures . On

4503-478: The horizontal, vertical and diagonal axes and moved about in the image. Not all blocks from the original image need to be used in the modified one. The top and left edge of a JPEG image must lie on an 8 × 8 pixel block boundary (or 16 × 16 pixel for larger MCU sizes), but the bottom and right edge need not do so. This limits the possible lossless crop operations, and prevents flips and rotations of an image whose bottom or right edge does not lie on

4582-416: The locations where each shape appears on the page. Thus, instead of compressing a letter "e" in a given font multiple times, it compresses the letter "e" once (as a compressed bit image) and then records every place on the page it occurs. Optionally, these shapes may be mapped to UTF-8 codes (either by hand or potentially by a text recognition system) and stored in the DjVu file. If this mapping exists, it

4661-496: The metadata in an almost-compliant way; the JFIF standard is interpreted somewhat flexibly. Strictly speaking, the JFIF and Exif standards are incompatible, because each specifies that its marker segment (APP0 or APP1, respectively) appear first. In practice, most JPEG files contain a JFIF marker segment that precedes the Exif header. This allows older readers to correctly handle the older format JFIF segment, while newer readers also decode

4740-565: The most recent being from 2005. The primary usage of the DjVu format has been the electronic distribution of documents with a quality comparable to that of printed documents. As that niche is also the primary usage for PDF, it was inevitable that the two formats would become competitors. It should however be observed that the two formats approach the problem of delivering high resolution documents in very different ways: PDF primarily encodes graphics and text as vectorised data, whereas DjVu primarily encodes them as pixmap images. This means PDF places

4819-463: The output bitstream. Nearly all software implementations of JPEG permit user control over the compression ratio (as well as other optional parameters), allowing the user to trade off picture-quality for smaller file size. In embedded applications (such as miniDV, which uses a similar DCT-compression scheme), the parameters are pre-selected and fixed for the application. The compression method is usually lossy , meaning that some original image information

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4898-459: The patent's validity. In light of the reexamination, the accused infringers in four of the five pending lawsuits have filed motions to suspend (stay) their cases until completion of the U.S. Patent and Trademark Office's review of the '341 patent. On April 23, 2008, a judge presiding over the two lawsuits in Chicago, Illinois granted the motions in those cases. On July 22, 2008, the Patent Office issued

4977-578: The patent. Forgent's 2002 announcement created a furor reminiscent of Unisys ' attempts to assert its rights over the GIF image compression standard. The JPEG committee investigated the patent claims in 2002 and were of the opinion that they were invalidated by prior art , a view shared by various experts. Between 2002 and 2004, Forgent was able to obtain about US$ 105 million by licensing their patent to some 30 companies. In April 2004, Forgent sued 31 other companies to enforce further license payments. In July of

5056-570: The prior art, yet it intentionally avoided telling the Patent Office. This makes any appeal to reinstate the patent highly unlikely to succeed. Forgent also possesses a similar patent granted by the European Patent Office in 1994, though it is unclear how enforceable it is. As of October 27, 2006, the U.S. patent's 20-year term appears to have expired, and in November 2006, Forgent agreed to abandon enforcement of patent claims against use of

5135-526: The process of reducing information is called quantization. In simpler terms, quantization is a method for optimally reducing a large number scale (with different occurrences of each number) into a smaller one, and the transform-domain is a convenient representation of the image because the high-frequency coefficients, which contribute less to the overall picture than other coefficients, are characteristically small-values with high compressibility. The quantized coefficients are then sequenced and losslessly packed into

5214-404: The purposes of display on webpages. A JPEG image consists of a sequence of segments , each beginning with a marker , each of which begins with a 0xFF byte, followed by a byte indicating what kind of marker it is. Some markers consist of just those two bytes; others are followed by two bytes (high then low), indicating the length of marker-specific payload data that follows. (The length includes

5293-576: The resource. The abstract XMP data model needs a concrete representation when it is stored or embedded into a file. As serialization format, a subset of the W3C RDF/XML syntax is most commonly used. It is a syntax to express a Resource Description Framework graph in XML. There are various equivalent ways to serialize the same XMP packet in RDF/XML. The most common metadata tags recorded in XMP data are those from

5372-543: The same quality and the edges coincide with block boundaries. The file format known as "JPEG Interchange Format" (JIF) is specified in Annex B of the standard. However, this "pure" file format is rarely used, primarily because of the difficulty of programming encoders and decoders that fully implement all aspects of the standard and because of certain shortcomings of the standard: Several additional standards have evolved to address these issues. The first of these, released in 1992,

5451-656: The same year, a consortium of 21 large computer companies filed a countersuit, with the goal of invalidating the patent. In addition, Microsoft launched a separate lawsuit against Forgent in April 2005. In February 2006, the United States Patent and Trademark Office agreed to re-examine Forgent's JPEG patent at the request of the Public Patent Foundation. On May 26, 2006, the USPTO found the patent invalid based on prior art. The USPTO also found that Forgent knew about

5530-448: The standardization of PDF in 2008, DjVu had been considered superior due to it being an open file format in contrast to the proprietary nature of PDF at the time. The declared higher compression ratio (and thus smaller file size), and the claimed ease of converting large volumes of text into DjVu format, were other arguments for DjVu's superiority over PDF in the technology landscape of 2004. Independent technologist Brewster Kahle in

5609-448: The text is stored. The background and foreground images are then compressed using a wavelet-based compression algorithm named IW44. The mask image is compressed using a method called JB2 (similar to JBIG2 ). The JB2 encoding method identifies nearly identical shapes on the page, such as multiple occurrences of a particular character in a given font, style, and size. It compresses the bitmap of each unique shape separately, and then encodes

5688-478: The thumbnail previews were later integrated in the Internet Archive's BookReader and DjVu browsing was deprecated in its favour as around 2015 some major browsers stopped supporting NPAPI and DjVu plugins with them. DjVu.js Viewer attempts to replace the missing plugins. The DjVu file format is based on the Interchange File Format and is composed of hierarchically organized chunks. The IFF structure

5767-509: The two bytes for the length, but not the two bytes for the marker.) Some markers are followed by entropy-coded data; the length of such a marker does not include the entropy-coded data. Note that consecutive 0xFF bytes are used as fill bytes for padding purposes, although this fill byte padding should only ever take place for markers immediately following entropy-coded scan data (see JPEG specification section B.1.1.2 and E.1.2 for details; specifically "In all cases where markers are appended after

5846-516: The wild with character substitutions, such as an n with bleeding serifs turning into a u and an o with a spot inside turning into an e. Whether lossy compression has occurred is not stored in the file. Thus the DjView viewing application can't warn the user that glyph substitutions might have occurred, neither when opening a lossy compressed file, nor in the Information or Metadata dialogue boxes. DjVu

5925-460: The world, and the most widely used digital image format , with several billion JPEG images produced every day as of 2015. The Joint Photographic Experts Group 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

6004-524: Was a simpler problem for which free software was available, there were suggestions that the free software movement should employ DjVu instead of PDF for distributing documentation; rendering for creating DjVu is in principle not much different from rendering for a device-specific printer driver, and DjVu can as a last resort be generated from scans of paper media. However, when FreeType 2.0 in 2000 began to provide rendering of all major vectorised font formats, that specific advantage of DjVu began to erode. In

6083-504: Was released publicly on March 21, 2005. A set of custom panels for Adobe Photoshop CS can be downloaded from the IPTC. The package includes a User's Guide, example photos with embedded XMP information, the specification document, and an implementation guide for developers. The "User's Guide to the IPTC Core" goes into detail about how each of the fields should be used and is also available directly as

6162-469: Was the JPEG File Interchange Format (or JFIF), followed in recent years by Exchangeable image file format (Exif) and ICC color profiles . Both of these formats use the actual JIF byte layout, consisting of different markers , but in addition, employ one of the JIF standard's extension points, namely the application markers : JFIF uses APP0, while Exif uses APP1. Within these segments of

6241-617: Was valid. Global Patent Holdings then filed a number of lawsuits based on claim 17 of its patent. In its first two lawsuits following the reexamination, both filed in Chicago, Illinois, Global Patent Holdings sued the Green Bay Packers , CDW , Motorola , Apple , Orbitz , Officemax , Caterpillar , Kraft and Peapod as defendants. A third lawsuit was filed on December 5, 2007, in South Florida against ADT Security Services , AutoNation , Florida Crystals Corp., HearUSA, MovieTickets.com , Ocwen Financial Corp. and Tire Kingdom , and

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