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114-471: The Graphics Interchange Format ( GIF ; / ɡ ɪ f / GHIF or / dʒ ɪ f / JIF , see § Pronunciation ) is a bitmap image format that was developed by a team at the online services provider CompuServe led by American computer scientist Steve Wilhite and released on June 15, 1987. The format can contain up to 8 bits per pixel , allowing a single image to reference its own palette of up to 256 different colors chosen from

228-587: A US$ 1 billion suit was filed against the company alleging that it permitted Hamas to use it to perform assaults that cost the lives of four people. Facebook released its blueprints of Surround 360 camera on GitHub under an open-source license . In September, it won an Emmy for its animated short "Henry". In October, Facebook announced a fee-based communications tool called Workplace that aims to "connect everyone" at work. Users can create profiles, see updates from co-workers on their news feed, stream live videos and participate in secure group chats. Following

342-589: A 1.6% share of Facebook for $ 240 million ($ 353 million in 2023 dollars ), giving Facebook a total implied value of around $ 15 billion ($ 22 billion in 2023 dollars ). Microsoft's purchase included rights to place international advertisements. In May 2007, at the first f8 developers conference, Facebook announced the launch of the Facebook Developer Platform , providing a framework for software developers to create applications that interact with core Facebook features . By

456-448: A GIF file describes a fixed-sized graphical area (the "logical screen") populated with zero or more "images". Many GIF files have a single image that fills the entire logical screen. Others divide the logical screen into separate sub-images. The images may also function as animation frames in an animated GIF file, but again these need not fill the entire logical screen. GIF files start with a fixed-length header ("GIF87a" or "GIF89a") giving

570-697: A German social network that was alleged to be visually and functionally similar to Facebook. In October 2008, Facebook announced that its international headquarters would locate in Dublin , Ireland. A January 2009 Compete.com study ranked Facebook the most used social networking service by worldwide monthly active users . China blocked Facebook in 2009 following the Ürümqi riots . In 2009, Yuri Milner 's DST (which later split into DST Global and Mail.ru Group ), alongside Uzbek Russian metals magnate Alisher Usmanov , invested $ 200 million in Facebook when it

684-485: A PR firm that had originally been hired to monitor press coverage of the company to address concerns primarily regarding Russian meddling , then mishandling of user data by Cambridge Analytica , hate speech on Facebook, and calls for regulation. Company spokesman Tim Miller stated that a goal for tech firms should be to "have positive content pushed out about your company and negative content that's being pushed out about your competitor". Definers claimed that George Soros

798-606: A Q&A session at Tsinghua University in Beijing , China , on October 23, where he attempted to converse in Mandarin. Zuckerberg hosted visiting Chinese politician Lu Wei , known as the "Internet czar" for his influence in China's online policy, on December 8. As of 2015 , Facebook's algorithm was revised in an attempt to filter out false or misleading content, such as fake news stories and hoaxes. It relied on users who flag

912-484: A dating platform, end-to-end encryption on its platforms, and allowing users on Messenger to communicate directly with WhatsApp and Instagram users. On July 31, 2019, Facebook announced a partnership with University of California, San Francisco to build a non-invasive, wearable device that lets people type by simply imagining themselves talking. On August 13, 2019, it was revealed that Facebook had enlisted hundreds of contractors to create and obtain transcripts of

1026-400: A focused electron beam . By association, it can also refer to a rectangular grid of pixels. The word rastrum is now used to refer to a device for drawing musical staff lines. The fundamental strategy underlying the raster data model is the tessellation of a plane, into a two-dimensional array of squares, each called a cell or pixel (from "picture element"). In digital photography ,

1140-502: A limited number of colors, such as logos. This takes advantage of the format's lossless compression, which favors flat areas of uniform color with well defined edges. They can also be used to store low-color sprite data for games. GIFs can be used for small animations and low-resolution video clips, or as reactions in online messaging used to convey emotion and feelings instead of using words. They are popular on social media platforms such as Tumblr , Facebook and Twitter . Conceptually,

1254-467: A partially downloaded image was somewhat recognizable, also helped GIF's popularity, as a user could abort the download if it was not what was required. In May 2015 Facebook added support for GIF. In January 2018 Instagram also added GIF stickers to the story mode. In 2016 the Internet Archive released a searchable library of GIFs from their Geocities archive. As a noun , the word GIF

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1368-425: A printer setting of 1200 DPI. Raster-based image editors, such as PaintShop Pro , Corel Painter , Adobe Photoshop , Paint.NET , Microsoft Paint , Krita , and GIMP , revolve around editing pixels , unlike vector-based image editors, such as Xfig , CorelDRAW , Adobe Illustrator , or Inkscape , which revolve around editing lines and shapes ( vectors ). When an image is rendered in a raster-based image editor,

1482-408: A radical Islamist imam believed to be the mastermind behind the 2019 Sri Lanka Easter bombings , preached on a pro- ISIL Facebook account, known as "Al-Ghuraba" media. On May 2, 2019, at F8, the company announced its new vision with the tagline "the future is private". A redesign of the website and mobile app was introduced, dubbed as "FB5". The event also featured plans for improving groups,

1596-423: A raster approach. Each on-screen pixel directly corresponds to a small number of bits in memory. The screen is refreshed simply by scanning through pixels and coloring them according to each set of bits. The refresh procedure, being speed critical, is often implemented by dedicated circuitry, often as a part of a graphics processing unit . Using this approach, the computer contains an area of memory that holds all

1710-415: A search of the table for each pixel. A linear search through up to 4096 addresses would make the coding slow. In practice the codes can be stored in order of numerical value; this allows each search to be done by a SAR (Successive Approximation Register, as used in some ADCs ), with only 12 magnitude comparisons. For this efficiency an extra table is needed to convert between codes and actual memory addresses;

1824-436: A share price of US$ 38 ($ 50.00 in 2023 dollars ). The company was valued at $ 104 billion ($ 138 billion in 2023 dollars ), the largest valuation to that date. The IPO raised $ 16 billion ($ 21.2 billion in 2023 dollars ), the third-largest in U.S. history, after Visa Inc. in 2008 and AT&T Wireless in 2000. Based on its 2012 income of $ 5 billion ($ 6.64 billion in 2023 dollars ), Facebook joined

1938-405: A six-month cycle, Facebook committed to work with ten to 15 data-driven startups there. On April 18, Facebook announced the beta launch of Facebook Spaces at its annual F8 developer conference. Facebook Spaces is a virtual reality version of Facebook for Oculus VR goggles. In a virtual and shared space, users can access a curated selection of 360-degree photos and videos using their avatar, with

2052-521: A story accordingly. Facebook maintained that satirical content should not be intercepted. The algorithm was accused of maintaining a " filter bubble ", where material the user disagrees with and posts with few likes would be deprioritized. In November, Facebook extended paternity leave from 4 weeks to 4 months. On April 12, 2016, Zuckerberg outlined his 10-year vision, which rested on three main pillars: artificial intelligence , increased global connectivity, and virtual and augmented reality . In July,

2166-849: A subsidiary named Lianshu Science & Technology in Hangzhou City , China, with $ 30 million ($ 36.4 million in 2023 dollars ) of capital. All its shares are held by Facebook Hong. Approval of the registration of the subsidiary was then withdrawn, due to a disagreement between officials in Zhejiang province and the Cyberspace Administration of China . On July 26, Facebook became the first company to lose over $ 100 billion ($ 121 billion in 2023 dollars ) worth of market capitalization in one day, dropping from nearly $ 630 billion to $ 510 billion after disappointing sales reports. On July 31, Facebook said that

2280-399: A very different meaning, and this can be misleading. Because, through the dithering process, the printer builds a single image pixel out of several printer dots to increase color depth , the printer's DPI setting must be set far higher than the desired PPI to ensure sufficient color depth without sacrificing image resolution. Thus, for instance, printing an image at 250 PPI may actually require

2394-597: A website he shared with his classmates. A " face book " is a student directory featuring photos and personal information. In 2003, Harvard had only a paper version along with private online directories. Zuckerberg told The Harvard Crimson , "Everyone's been talking a lot about a universal face book within Harvard. ... I think it's kind of silly that it would take the University a couple of years to get around to it. I can do it better than they can, and I can do it in

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2508-511: A week." In January 2004, Zuckerberg coded a new website, known as "TheFacebook", inspired by a Crimson editorial about Facemash, stating, "It is clear that the technology needed to create a centralized Website is readily available ... the benefits are many." Zuckerberg met with Harvard student Eduardo Saverin , and each of them agreed to invest $ 1,000 ($ 1,613 in 2023 dollars ) in the site. On February 4, 2004, Zuckerberg launched "TheFacebook", originally located at thefacebook.com. Six days after

2622-448: Is 2, even if only values 0 and 1 are used. The code table initially contains codes that are one bit longer than the symbol size in order to accommodate the two special codes clr and end and codes for strings that are added during the process. When the table is full the code length increases to give space for more strings, up to a maximum code 4095 = FFF(hex). As the decoder builds its table it tracks these increases in code length and it

2736-441: Is able to unpack incoming bytes accordingly. A 46×46 uncompressed GIF with 7-bit symbols (128 colors, 8-bit codes). Click on the image for an explanation of the code. Raster graphics The printing and prepress industries know raster graphics as contones (from continuous tones ). In contrast, line art is usually implemented as vector graphics in digital systems. Many raster manipulations map directly onto

2850-524: Is almost never used for true color images, it is possible to do so. A GIF image can include multiple image blocks, each of which can have its own 256-color palette, and the blocks can be tiled to create a complete image. Alternatively, the GIF89a specification introduced the idea of a "transparent" color where each image block can include its own palette of 255 visible colors plus one transparent color. A complete image can be created by layering image blocks with

2964-402: Is based on a (usually rectangular, square-based) tessellation of the 2D plane into cells, each containing a single value. To store the data in a file, the two-dimensional array must be serialized. The most common way to do this is a row-major format, in which the cells along the first (usually top) row are listed left to right, followed immediately by those of the second row, and so on. In

3078-652: Is found in the newer editions of many dictionaries. In 2012, the American wing of the Oxford University Press recognized GIF as a verb as well, meaning "to create a GIF file", as in "GIFing was the perfect medium for sharing scenes from the Summer Olympics ". The press's lexicographers voted it their word of the year , saying that GIFs have evolved into "a tool with serious applications including research and journalism". The pronunciation of

3192-460: Is lost, although certain vectorization operations can recreate salient information, as in the case of optical character recognition . Early mechanical televisions developed in the 1920s employed rasterization principles. Electronic television based on cathode-ray tube displays are raster scanned with horizontal rasters painted left to right, and the raster lines painted top to bottom. Modern flat-panel displays such as LED monitors still use

3306-476: Is prefixed with a byte indicating the number of data bytes in the sub-block. The series of sub-blocks is terminated by an empty sub-block (a single 0 byte, indicating a sub-block with 0 data bytes). For the sample image above the reversible mapping between 9-bit codes and bytes is shown below. A slight compression is evident: pixel colors defined initially by 15 bytes are exactly represented by 12 code bytes including control codes. The encoding process that produces

3420-424: Is then stored for each pixel. For most images, this value is a visible color, but other measurements are possible, even numeric codes for qualitative categories. Each raster grid has a specified pixel format , the data type for each number. Common pixel formats are binary , gray-scale , palettized , and full-color , where color depth determines the fidelity of the colors represented, and color space determines

3534-512: Is vector, rendering specifications and software such as PostScript are used to create the raster image. Three-dimensional voxel raster graphics are employed in video games and are also used in medical imaging such as MRI scanners . Geographic phenomena are commonly represented in a raster format in GIS . The raster grid is georeferenced , so that each pixel (commonly called a cell in GIS because

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3648-461: The 2016 U.S. presidential election , Facebook announced that it would combat fake news by using fact checkers from sites like FactCheck.org and Associated Press (AP), making reporting hoaxes easier through crowdsourcing, and disrupting financial incentives for abusers. On January 17, 2017, Facebook COO Sheryl Sandberg planned to open Station F, a startup incubator campus in Paris , France . On

3762-427: The 24-bit RGB color space . It can also represent multiple images in a file, which can be used for animations , and allows a separate palette of up to 256 colors for each frame. These palette limitations make GIF less suitable for reproducing color photographs and other images with color gradients but well-suited for simpler images such as graphics or logos with solid areas of color. GIF images are compressed using

3876-666: The Exif standard. High-resolution raster grids contain a large number of pixels, and thus consume a large amount of memory. This has led to multiple approaches to compressing the data volume into smaller files. The most common strategy is to look for patterns or trends in the pixel values, then store a parameterized form of the pattern instead of the original data. Common raster compression algorithms include run-length encoding (RLE), JPEG , LZ (the basis for PNG and ZIP ), Lempel–Ziv–Welch (LZW) (the basis for GIF ), and others. For example, Run length encoding looks for repeated values in

3990-926: The Fortune 500 list for the first time in May 2013, ranked 462. The shares set a first-day record for trading volume of an IPO (460 million shares). The IPO was controversial given the immediate price declines that followed, and was the subject of lawsuits, while SEC and FINRA both launched investigations. Zuckerberg announced at the start of October 2012 that Facebook had one billion monthly active users, including 600 million mobile users, 219 billion photo uploads and 140 billion friend connections. On October 1, 2012, Zuckerberg visited Russian Prime Minister Dmitry Medvedev in Moscow to stimulate social media innovation in Russia and to boost Facebook's position in

4104-603: The Huffington Post reported that Facebook's PR agency had paid someone to tweak Facebook COO Sheryl Sandberg 's Misplaced Pages page, as well as adding a page for the global head of PR, Caryn Marooney. In March 2019, the perpetrator of the Christchurch mosque shootings in New Zealand used Facebook to stream live footage of the attack as it unfolded. Facebook took 29 minutes to detect the livestreamed video, which

4218-671: The Lempel–Ziv–Welch (LZW) lossless data compression technique to reduce the file size without degrading the visual quality. While once in widespread usage on the World Wide Web because of its wide implementation and portability between applications and operating systems, usage of the format has declined for space and quality reasons, often being replaced with video formats such as the MP4 file format . These replacements, in turn, are sometimes termed "GIFs" despite having no relation to

4332-458: The face book directories often given to American university students. Membership was initially limited to Harvard students, gradually expanding to other North American universities. Since 2006, Facebook allows everyone to register from 13 years old, except in the case of a handful of nations, where the age limit is 14 years. As of December 2022 , Facebook claimed almost 3 billion monthly active users. As of October 2023, Facebook ranked as

4446-486: The second annual f8 developers conference on July 23, 2008, the number of applications on the platform had grown to 33,000, and the number of registered developers had exceeded 400,000. The website won awards such as placement into the "Top 100 Classic Websites" by PC Magazine in 2007, and winning the "People's Voice Award" from the Webby Awards in 2008. In early 2008, Facebook became EBITDA profitable, but

4560-744: The third-most-visited website in the world , with 22.56% of its traffic coming from the United States. It was the most downloaded mobile app of the 2010s. Facebook can be accessed from devices with Internet connectivity, such as personal computers , tablets and smartphones . After registering, users can create a profile revealing personal information about themselves. They can post text, photos and multimedia which are shared with any other users who have agreed to be their friend or, with different privacy settings , publicly. Users can also communicate directly with each other with Messenger , join common-interest groups, and receive notifications on

4674-551: The visible spectrum ; the large CCD bitmapped sensor at the Vera C. Rubin Observatory captures 3.2 gigapixels in a single image (6.4 GB raw), over six color channels which exceed the spectral range of human color vision. Most computer images are stored in raster graphics formats or compressed variations, including GIF , JPEG , and PNG , which are popular on the World Wide Web . A raster data structure

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4788-446: The "picture" part of "pixel" is not relevant) represents a square region of geographic space. The value of each cell then represents some measurable ( qualitative or quantitative ) property of that region, typically conceptualized as a field . Examples of fields commonly represented in rasters include: temperature, population density, soil moisture, land cover, surface elevation, etc. Two sampling models are used to derive cell values from

4902-422: The 9-bit codes is shown below. A local string accumulates pixel color numbers from the palette, with no output action as long as the local string can be found in a code table. There is special treatment of the first two pixels that arrive before the table grows from its initial size by additions of strings. After each output code, the local string is initialized to the latest pixel color (that could not be included in

5016-730: The Digital Forensic Research Lab Facebook partners with the Atlantic Council , a NATO -affiliated think tank. In November, Facebook launched smart displays branded Portal and Portal Plus (Portal+). They support Amazon 's Alexa (intelligent personal assistant service). The devices include video chat function with Facebook Messenger. In August 2018, a lawsuit was filed in Oakland, California claiming that Facebook created fake accounts in order to inflate its user data and appeal to advertisers in

5130-544: The GIF specification, dithering can be used in images subsequently encoded as GIF images. This is often not an ideal solution for GIF images, both because the loss of spatial resolution typically makes an image look fuzzy on the screen, and because the dithering patterns often interfere with the compressibility of the image data, working against GIF's main purpose. In the early days of graphical web browsers, graphics cards with 8-bit buffers (allowing only 256 colors) were common and it

5244-408: The GIF specification. GIF is palette-based: the colors used in an image (a frame) in the file have their RGB values defined in a palette table that can hold up to 256 entries, and the data for the image refer to the colors by their indices (0–255) in the palette table. The color definitions in the palette can be drawn from a color space of millions of shades (2 shades, 8 bits for each primary), but

5358-522: The Russian market. On January 15, 2013, Facebook announced Facebook Graph Search , which provides users with a "precise answer", rather than a link to an answer by leveraging data present on its site. Facebook emphasized that the feature would be "privacy-aware", returning results only from content already shared with the user. On April 3, 2013, Facebook unveiled Facebook Home , a user-interface layer for Android devices offering greater integration with

5472-460: The United States and Canada . In mid-2004, Napster co-founder and entrepreneur Sean Parker —an informal advisor to Zuckerberg—became company president. In June 2004, the company moved to Palo Alto, California . Sean Parker called Reid Hoffman to fund Facebook. However, Reid Hoffman was too busy launching LinkedIn so he set Facebook up with PayPal co-founder Peter Thiel , who gave Facebook its first investment later that month. In 2005,

5586-543: The acquisition of FB.com one of the ten highest domain sales in history. In February 2011, Facebook announced plans to move its headquarters to the former Sun Microsystems campus in Menlo Park, California. In March 2011, it was reported that Facebook was removing about 20,000 profiles daily for violations such as spam , graphic content and underage use, as part of its efforts to boost cyber security . Statistics showed that Facebook reached one trillion page views in

5700-687: The activities of their Facebook friends and the pages they follow. The subject of numerous controversies , Facebook has often been criticized over issues such as user privacy (as with the Cambridge Analytica data scandal ), political manipulation (as with the 2016 U.S. elections ) and mass surveillance. Facebook has also been subject to criticism over psychological effects such as addiction and low self-esteem , and various controversies over content such as fake news , conspiracy theories , copyright infringement , and hate speech . Commentators have accused Facebook of willingly facilitating

5814-503: The array, and replaces them with the value and the number of times it appears. Thus, the raster above would be represented as: This technique is very efficient when there are large areas of identical values, such as a line drawing, but in a photograph where pixels are usually slightly different from their neighbors, the RLE file would be up to twice the size of the original. Some compression algorithms, such as RLE and LZW, are lossless , where

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5928-414: The audio messages of users. This was especially common of Facebook Messenger, where the contractors frequently listened to and transcribed voice messages of users. After this was first reported on by Bloomberg News , Facebook released a statement confirming the report to be true, but also stated that the monitoring program was now suspended. On September 5, 2019, Facebook launched Facebook Dating in

6042-443: The color of the pixel in the same position from the background, which may have been determined by a previous frame of animation. Many techniques, collectively called dithering , have been developed to approximate a wider range of colors with a small color palette by using pixels of two or more colors to approximate in-between colors. These techniques sacrifice spatial resolution to approximate deeper color resolution. While not part of

6156-416: The company dropped "the" from its name after purchasing the domain name Facebook.com for US$ 200,000 ($ 312,012 in 2023 dollars ). The domain had belonged to AboutFace Corporation. In May 2005, Accel Partners invested $ 12.7 million ($ 19.8 million in 2023 dollars ) in Facebook, and Jim Breyer added $ 1 million ($ 1.56 million in 2023 dollars ) of his own money. A high-school version of

6270-545: The company had deleted 17 accounts related to the 2018 U.S. midterm elections . On September 19, Facebook announced that, for news distribution outside the United States, it would work with U.S. funded democracy promotion organizations, International Republican Institute and the National Democratic Institute , which are loosely affiliated with the Republican and Democratic parties. Through

6384-426: The complete, full-color image appears. For example, breaking an image into tiles of 16 by 16 pixels (256 pixels in total) ensures that no tile has more than the local palette limit of 256 colors, although larger tiles may be used and similar colors merged resulting in some loss of color information. Since each image block can have its own local color table, a GIF file having many image blocks can be very large, limiting

6498-472: The data that are to be displayed. The central processor writes data into this region of memory and the video controller collects them from there. The bits of data stored in this block of memory are related to the eventual pattern of pixels that will be used to construct an image on the display. An early scanned display with raster computer graphics was invented in the late 1960s by A. Michael Noll at Bell Labs , but its patent application filed February 5, 1970,

6612-430: The developing world. The company celebrated its 10th anniversary during the week of February 3, 2014. In January 2014, over one billion users connected via a mobile device. As of June, mobile accounted for 62% of advertising revenue, an increase of 21% from the previous year. By September Facebook's market capitalization had exceeded $ 200 billion ($ 257 billion in 2023 dollars ). Zuckerberg participated in

6726-532: The development of the Portable Network Graphics (PNG) standard. In 2004, all patents relating to the proprietary compression used for GIF expired. The feature of storing multiple images in one file, accompanied by control data, is used extensively on the Web to produce simple animations . The optional interlacing feature, which stores image scan lines out of order in such a fashion that even

6840-517: The edge of the box. Following a campaign by 100 advocacy groups, Facebook agreed to update its policy on hate speech. The campaign highlighted content promoting domestic violence and sexual violence against women and led 15 advertisers to withdraw, including Nissan UK, House of Burlesque, and Nationwide UK. The company initially stated, "while it may be vulgar and offensive, distasteful content on its own does not violate our policies". It took action on May 29. On June 12, Facebook announced that it

6954-478: The example at right, the cells of tessellation A are overlaid on the point pattern B resulting in an array C of quadrant counts representing the number of points in each cell. For purposes of visualization a lookup table has been used to color each of the cells in an image D. Here are the numbers as a serial row-major array: 1 3 0 0 1 12 8 0 1 4 3 3 0 2 0 2 1 7 4 1 5 4 2 2 0 3 1 2 2 2 2 3 0 5 1 9 3 3 3 4 5 0 8 0 2 4 3 2 8 4 3 2 2 7 2 3 2 10 1 5 2 1 3 7 To reconstruct

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7068-457: The example. If the palette is only 64 colors (so color indexes are 6 bits wide), the symbols can range from 0 to 63, and the symbol width can be taken to be 6 bits, with codes starting at 7 bits. In fact, the symbol width need not match the palette size: as long as the values decoded are always less than the number of colors in the palette, the symbols can be any width from 2 to 8, and the palette size any power of 2 from 2 to 256. For example, if only

7182-408: The extra table upkeeping is needed only when a new code is stored which happens at much less than pixel rate. Decoding begins by mapping the stored bytes back to 9-bit codes. These are decoded to recover the pixel colors as shown below. A table identical to the one used in the encoder is built by adding strings by this rule: Shorter code lengths can be used for palettes smaller than the 256 colors in

7296-407: The field: in a lattice , the value is measured at the center point of each cell; in a grid , the value is a summary (usually a mean or mode) of the value over the entire cell. Raster graphics are resolution dependent, meaning they cannot scale up to an arbitrary resolution without loss of apparent quality . This property contrasts with the capabilities of vector graphics , which easily scale up to

7410-414: The first code is stored in the least significant bit of the first byte, higher order bits of the code into higher order bits of the byte, spilling over into the low order bits of the next byte as necessary. Each subsequent code is stored starting at the least significant bit not already used. This byte stream is stored in the file as a series of "sub-blocks". Each sub-block has a maximum length 255 bytes and

7524-419: The first four colors (values 0 to 3) of the palette are used, the symbols can be taken to be 2 bits wide with codes starting at 3 bits. Conversely, the symbol width could be set at 8, even if only values 0 and 1 are used; these data would only require a two-color table. Although there would be no point in encoding the file that way, something similar typically happens for bi-color images: the minimum symbol width

7638-490: The first letter of GIF has been disputed since the 1990s. The most common pronunciations in English are / dʒ ɪ f / (with a soft g as in gin ) and / ɡ ɪ f / (with a hard g as in gift ), differing in the phoneme represented by the letter G . The creators of the format pronounced the acronym GIF as / dʒ ɪ f / , with a soft g , with Wilhite stating that he intended for

7752-413: The following tables are in little-endian byte order, as the format specification prescribes. The image pixel data, scanned horizontally from top left, are converted by LZW encoding to codes that are then mapped into bytes for storing in the file. The pixel codes typically don't match the 8-bit size of the bytes, so the codes are packed into bytes by a "little-Endian" scheme: the least significant bit of

7866-763: The image is composed of millions of pixels. At its core, a raster image editor works by manipulating each individual pixel. Most pixel-based image editors work using the RGB color model , but some also allow the use of other color models such as the CMYK color model . Facebook Facebook is a social media and social networking service owned by American technology conglomerate Meta . Created in 2004 by Mark Zuckerberg with four other Harvard College students and roommates Eduardo Saverin , Andrew McCollum , Dustin Moskovitz , and Chris Hughes , its name derives from

7980-453: The mathematical formalisms of linear algebra , where mathematical objects of matrix structure are of central concern. The word "raster" has its origins in the Latin rastrum (a rake), which is derived from radere (to scrape). It originates from the raster scan of cathode-ray tube (CRT) video monitors , which draw the image line by line by magnetically or electrostatically steering

8094-408: The maximum number of colors a frame can use is 256. This limitation was reasonable when GIF was developed because hardware that could display more than 256 colors simultaneously was rare. Simple graphics, line drawings, cartoons, and grey-scale photographs typically need fewer than 256 colors. Each frame can designate one index as a "transparent background color": any pixel assigned this index takes on

8208-471: The month of June 2011, making it the most visited website tracked by DoubleClick . According to a Nielsen study, Facebook had in 2011 become the second-most accessed website in the U.S. behind Google . In March 2012, Facebook announced App Center, a store selling applications that operate via the website. The store was to be available on iPhones , Android devices, and for mobile web users. Facebook's initial public offering came on May 17, 2012, at

8322-496: The most appropriate image resolution for a given printer-resolution can pose difficulties, since printed output may have a greater level of detail than a viewer can discern on a monitor. Typically, a resolution of 150 to 300 PPI works well for 4-color process ( CMYK ) printing. However, for printing technologies that perform color mixing through dithering ( halftone ) rather than through overprinting (virtually all home/office inkjet and laser printers), printer DPI and image PPI have

8436-436: The most widely shared political content on Facebook. In May 2018 at F8 , the company announced it would offer its own dating service. Shares in competitor Match Group fell by 22%. Facebook Dating includes privacy features and friends are unable to view their friends' dating profile. In July, Facebook was charged £500,000 by UK watchdogs for failing to respond to data erasure requests. On July 18, Facebook established

8550-532: The next-highest county, New York County (better known as Manhattan ), at roughly $ 110,000 a year ($ 145,986 in 2023 dollars ). Facebook joined Alliance for Affordable Internet (A4AI) in October, as it launched. The A4AI is a coalition of public and private organizations that includes Google , Intel and Microsoft. Led by Sir Tim Berners-Lee , the A4AI seeks to make Internet access more affordable to ease access in

8664-504: The original file format. CompuServe introduced GIF on 15 June 1987 to provide a color image format for their file downloading areas. This replaced their earlier run-length encoding format, which was black and white only. GIF became popular because it used Lempel–Ziv–Welch data compression . Since this was more efficient than the run-length encoding used by PCX and MacPaint , fairly large images could be downloaded reasonably quickly even with slow modems . The original version of GIF

8778-474: The original pixel values can be perfectly regenerated from the compressed data. Other algorithms, such as JPEG, are lossy , because the parameterized patterns are only an approximation of the original pixel values, so the latter can only be estimated from the compressed data. Vector images (line work) can be rasterized (converted into pixels), and raster images vectorized (raster images converted into vector graphics), by software. In both cases some information

8892-456: The output code). For clarity the table is shown above as being built of strings of increasing length. That scheme can function but the table consumes an unpredictable amount of memory. Memory can be saved in practice by noting that each new string to be stored consists of a previously stored string augmented by one character. It is economical to store at each address only two words: an existing address and one character. The LZW algorithm requires

9006-468: The owners of the Jif brand, partnered with the animated image database and search engine Giphy to release a limited-edition "Jif vs. GIF" ( hashtagged as #JIFvsGIF) jar of peanut butter that had a label humorously declaring the soft- g pronunciation to refer exclusively to the peanut butter, and GIF to be exclusively pronounced with the hard- g pronunciation. GIFs are suitable for sharp-edged line art with

9120-455: The plane is the visual field as projected onto the image sensor ; in computer art , the plane is a virtual canvas; in geographic information systems , the plane is a projection of the Earth's surface. The size of each square pixel, known as the resolution or support , is constant across the grid. Raster or gridded data may be the result of a gridding procedure. A single numeric value

9234-468: The presence and size of a Local Color Table (which follows next if present). The image data follows: one byte giving the bit width of the unencoded symbols (which must be at least 2 bits wide, even for bi-color images), followed by a series of sub-blocks containing the LZW-encoded data. Extension blocks (blocks that "extend" the 87a definition via a mechanism already defined in the 87a spec) consist of

9348-411: The primary pronunciation, while Cambridge Dictionary of American English offers only the hard- g pronunciation. Merriam-Webster's Collegiate Dictionary and Oxford Dictionaries cite both pronunciations, but place the hard g first: / ɡ ɪ f , dʒ ɪ f / . The New Oxford American Dictionary gave only / dʒ ɪ f / in its second edition but updated it to / dʒ ɪ f , ɡ ɪ f / in

9462-466: The process. In January 2019, the 10-year challenge was started asking users to post a photograph of themselves from 10 years ago (2009) and a more recent photo. Criticized for its role in vaccine hesitancy , Facebook announced in March 2019 that it would provide users with "authoritative information" on the topic of vaccines. A study published in the journal Vaccine of advertisements posted in

9576-439: The pronunciation to deliberately echo the American peanut butter brand Jif , and CompuServe employees would often quip "choosy developers choose GIF", a spoof of Jif's television commercials. However, the word is widely pronounced as / ɡ ɪ f / , with a hard g , and polls have generally shown that this hard g pronunciation is more prevalent. Dictionary.com cites both pronunciations, indicating / dʒ ɪ f / as

9690-409: The quality of the device rendering them. Raster graphics deal more practically than vector graphics with photographs and photo-realistic images, while vector graphics often serve better for typesetting or for graphic design . Modern computer-monitors typically display about 72 to 130 pixels per inch (PPI), and some modern consumer printers can resolve 2400 dots per inch (DPI) or more; determining

9804-399: The range of color coverage (which is often less than the full range of human color vision ). Most modern color raster formats represent color using 24 bits (over 16 million distinct colors), with 8 bits (values 0–255) for each color channel (red, green, and blue). The digital sensors used for remote sensing and astronomy are often able to detect and store wavelengths beyond

9918-512: The sentinel, an additional byte specifying the type of extension, and a series of sub-blocks with the extension data. Extension blocks that modify an image (like the Graphic Control Extension that specifies the optional animation delay time and optional transparent background color) must immediately precede the segment with the image they refer to. Each sub-block begins with a byte giving the number of subsequent data bytes in

10032-622: The site launched in September 2005. Eligibility expanded to include employees of several companies, including Apple Inc. and Microsoft . In May 2006, Facebook hired its first intern, Julie Zhuo . After a month, Zhuo was hired as a full-time engineer. On September 26, 2006, Facebook opened to everyone at least 13 years old with a valid email address . By late 2007, Facebook had 100,000 pages on which companies promoted themselves. Organization pages began rolling out in May 2009. On October 24, 2007, Microsoft announced that it had purchased

10146-635: The site launched, Harvard seniors Cameron Winklevoss , Tyler Winklevoss , and Divya Narendra accused Zuckerberg of intentionally misleading them into believing that he would help them build a social network called HarvardConnection.com . They claimed that he was instead using their ideas to build a competing product. The three complained to the Crimson and the newspaper began an investigation. They later sued Zuckerberg, settling in 2008 for 1.2 million shares (worth $ 300 million at Facebook's IPO , or $ 398 million in 2023 dollars ). Membership

10260-489: The site. HTC announced HTC First , a phone with Home pre-loaded. On April 15, 2013, Facebook announced an alliance across 19 states with the National Association of Attorneys General, to provide teenagers and parents with information on tools to manage social networking profiles. On April 19 Facebook modified its logo to remove the faint blue line at the bottom of the "F" icon. The letter F moved closer to

10374-486: The spread of such content, as well as exaggerating its number of users to appeal to advertisers. Zuckerberg built a website called "Facemash" in 2003 while attending Harvard University . The site was comparable to Hot or Not and used "photos compiled from the online face books of nine Houses, placing two next to each other at a time and asking users to choose the 'hotter' person". Facemash attracted 450 visitors and 22,000 photo-views in its first four hours. The site

10488-406: The sub-block (1 to 255). The series of sub-blocks is terminated by an empty sub-block (a 0 byte). This structure allows the file to be parsed even if not all parts are understood. A GIF marked 87a may contain extension blocks; the intent is that a decoder can read and display the file without the features covered in extensions it does not understand. The full detail of the file format is covered in

10602-444: The support of the controller. Users can access their own photos and videos, along with media shared on their newsfeed. In September, Facebook announced it would spend up to US$ 1 billion on original shows for its Facebook Watch platform. On October 16, it acquired the anonymous compliment app tbh , announcing its intention to leave the app independent. In October 2017, Facebook expanded its work with Definers Public Affairs ,

10716-505: The third edition. The disagreement over the pronunciation has led to heated Internet debate. On the occasion of receiving a lifetime achievement award at the 2013 Webby Awards ceremony, Wilhite publicly rejected the hard- g pronunciation; his speech led to more than 17,000 posts on Twitter and dozens of news articles. The White House and the TV program Jeopardy! also entered the debate in 2013. In February 2020, The J.M. Smucker Company ,

10830-513: The third year in a row. The company announced 500 million users in July 2010. Half of the site's membership used Facebook daily, for an average of 34 minutes, while 150 million users accessed the site from mobile devices. A company representative called the milestone a "quiet revolution". In October 2010 groups were introduced. In November 2010, based on SecondMarket Inc. (an exchange for privately held companies' shares), Facebook's value

10944-466: The three months prior to that found that 54% of the anti-vaccine advertisements on Facebook were placed by just two organisations funded by well-known anti-vaccination activists. The Children's Health Defense / World Mercury Project chaired by Robert F. Kennedy Jr. and Stop Mandatory Vaccination , run by campaigner Larry Cook, posted 54% of the advertisements. The ads often linked to commercial products, such as natural remedies and books. On March 14,

11058-423: The two-dimensional grid, the file must include a header section at the beginning that contains at least the number of columns, and the pixel datatype (especially the number of bits or bytes per value) so the reader knows where each value ends to start reading the next one. Headers may also include the number of rows, georeferencing parameters for geographic data, or other metadata tags, such as those specified in

11172-438: The usefulness of full-color GIFs. Additionally, not all GIF rendering programs handle tiled or layered images correctly. Many rendering programs interpret tiles or layers as animation frames and display them in sequence as an animation with most web browsers automatically displaying the frames with a delay time of 0.1 seconds or more. Sample image (enlarged), actual size 3 pixels wide by 5 high The hex numbers in

11286-449: The version, followed by a fixed-length Logical Screen Descriptor giving the pixel dimensions and other characteristics of the logical screen. The screen descriptor may also specify the presence and size of a Global Color Table (GCT), which follows next if present. Thereafter, the file is divided into segments of the following types, each introduced by a 1-byte sentinel: An image starts with a fixed-length Image Descriptor, which may specify

11400-454: The visible portion of each layer showing through the transparent portions of the layers above. To render a full-color image as a GIF, the original image must be broken down into smaller regions having no more than 255 or 256 different colors. Each of these regions is then stored as a separate image block with its own local palette and when the image blocks are displayed together (either by tiling or by layering partially transparent image blocks),

11514-619: Was $ 41 billion ($ 57.3 billion in 2023 dollars ). The company had slightly surpassed eBay to become the third largest American web company after Google and Amazon.com . On November 15, 2010, Facebook announced it had acquired the domain name fb.com from the American Farm Bureau Federation for an undisclosed amount. On January 11, 2011, the Farm Bureau disclosed $ 8.5 million ($ 11.5 million in 2023 dollars ) in "domain sales income", making

11628-469: Was abandoned at the Supreme Court in 1977 over the issue of the patentability of computer software. During the 1970s and 1980s, pen plotters , using Vector graphics , were common for creating precise drawings, especially on large format paper. However, since then almost all printers create the printed image as a raster grid, including both laser and inkjet printers. When the source information

11742-592: Was called 87a. This version already supported multiple images in a stream. In 1989, CompuServe released an enhanced version, called 89a, This version added: The two versions can be distinguished by looking at the first six bytes of the file (the " magic number " or signature), which, when interpreted as ASCII , read "GIF87a" or "GIF89a", respectively. CompuServe encouraged the adoption of GIF by providing downloadable conversion utilities for many computers. By December 1987, for example, an Apple IIGS user could view pictures created on an Atari ST or Commodore 64 . GIF

11856-457: Was eight minutes longer than it took police to arrest the gunman. About 1.3m copies of the video were blocked from Facebook but 300,000 copies were published and shared. Facebook has promised changes to its platform; spokesman Simon Dilner told Radio New Zealand that it could have done a better job. Several companies, including the ANZ and ASB banks, have stopped advertising on Facebook after the company

11970-702: Was fairly common to make GIF images using the websafe palette . This ensured predictable display, but severely limited the choice of colors. When 24-bit color became the norm, palettes could instead be populated with the optimum colors for individual images. A small color table may suffice for small images, and keeping the color table small allows the file to be downloaded faster. Both the 87a and 89a specifications allow color tables of 2 colors for any n from 1 through 8. Most graphics applications will read and display GIF images with any of these table sizes; but some do not support all sizes when creating images. Tables of 2, 16, and 256 colors are widely supported. Although GIF

12084-444: Was initially restricted to students of Harvard College . Within a month, more than half the undergraduates had registered. Dustin Moskovitz , Andrew McCollum , and Chris Hughes joined Zuckerberg to help manage the growth of the website. In March 2004, Facebook expanded to Columbia , Stanford and Yale . It then became available to all Ivy League colleges, Boston University , NYU , MIT , and successively most universities in

12198-446: Was introducing clickable hashtags to help users follow trending discussions, or search what others are talking about on a topic. San Mateo County , California, became the top wage-earning county in the country after the fourth quarter of 2012 because of Facebook. The Bureau of Labor Statistics reported that the average salary was 107% higher than the previous year, at $ 168,000 a year ($ 222,961 in 2023 dollars ), more than 50% higher than

12312-407: Was not cash flow positive yet. On July 20, 2008, Facebook introduced "Facebook Beta", a significant redesign of its user interface on selected networks. The Mini-Feed and Wall were consolidated, profiles were separated into tabbed sections, and an effort was made to create a cleaner look. Facebook began migrating users to the new version in September 2008. In July 2008, Facebook sued StudiVZ ,

12426-440: Was one of the first two image formats commonly used on Web sites, the other being the black-and-white XBM . In September 1995 Netscape Navigator 2.0 added the ability for animated GIFs to loop . While GIF was developed by CompuServe , it used the Lempel–Ziv–Welch (LZW) lossless data compression algorithm patented by Unisys in 1985. Controversy over the licensing agreement between Unisys and CompuServe in 1994 spurred

12540-495: Was reportedly unaware at the time. In May 2009, Zuckerberg said of the $ 200 million Russian investment, "This investment is purely buffer for us. It is not something we needed to get to cash flow positive." In September 2009, Facebook became cash flow positive ahead of schedule after closing a roughly $ 200 million gap in operating profitability. In 2010, Facebook won the Crunchie "Best Overall Startup Or Product" award for

12654-421: Was sent to several campus group listservs , but was shut down a few days later by Harvard administration. Zuckerberg faced expulsion and was charged with breaching security, violating copyrights and violating individual privacy. Ultimately, the charges were dropped. Zuckerberg expanded on this project that semester by creating a social study tool. He uploaded art images, each accompanied by a comments section, to

12768-453: Was the force behind what appeared to be a broad anti-Facebook movement, and created other negative media, along with America Rising , that was picked up by larger media organisations like Breitbart News . Facebook cut ties with the agency in late 2018, following public outcry over their association. Posts originating from the Facebook page of Breitbart News , a media organization previously affiliated with Cambridge Analytica, were among

12882-646: Was valued at $ 10 billion. A separate stake was also acquired by Usmanov's USM Holdings on another occasion. According to the New York Times in 2013, "Mr. Usmanov and other Russian investors at one point owned nearly 10 percent of Facebook, though precise details of their ownership stakes are difficult to assess." It was later revealed in 2017 by the Paradise Papers that lending by Russian state-backed VTB Bank and Gazprom 's investment vehicle partially financed these 2009 investments, although Milner

12996-618: Was widely condemned by the public. Following the attack, Facebook began blocking white nationalist , white supremacist , and white separatist content, saying that they could not be meaningfully separated. Previously, Facebook had only blocked overtly supremacist content. The older policy had been condemned by civil rights groups, who described these movements as functionally indistinct. Further bans were made in mid-April 2019, banning several British far-right organizations and associated individuals from Facebook, and also banning praise or support for them. NTJ 's member Moulavi Zahran Hashim,

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