A webcam is a video camera that feeds or streams an image or video in real time to or through a computer to a computer network, such as the Internet. Webcams are small cameras that sit on a desk, attach to a user's monitor, or are built into the hardware. Webcams can be used during a video chat session involving two or more people, with conversations that include live audio and video. For example, Apple's iSight camera, built into Apple laptops, iMacs and a number of iPhones, can be used for video chat sessions, using the iChat instant messaging program. Webcam software enables users to record a stream the video on the Internet; as video streaming over the Internet requires a lot of bandwidth, such streams use compressed formats. The maximum resolution of a webcam is lower than most handheld video cameras, as higher resolutions would be reduced during transmission; the lower resolution enables webcams to be inexpensive compared to most video cameras, but the effect is adequate for video chat sessions.
The term "webcam" may be used in its original sense of a video camera connected to the Web continuously for an indefinite time, rather than for a particular session supplying a view for anyone who visits its web page over the Internet. Some of them, for example, those used as online traffic cameras, are expensive, rugged professional video cameras. Webcams include a lens, an image sensor, support electronics, may include one or two microphones for sound. Image sensors can be CMOS or CCD, the former being dominant for low-cost cameras, but CCD cameras do not outperform CMOS-based cameras in the low-price range. Most consumer webcams are capable of providing VGA-resolution video at a frame rate of 30 frames per second. Many newer devices can produce video in multi-megapixel resolutions, a few can run at high frame rates such as the PlayStation Eye, which can produce 320×240 video at 120 frames per second; the Wii Remote contains an image sensor with a resolution of 1024×768 pixels. As the bayer filter is proprietary, any webcam contains some built-in image processing, separate from compression.
Various lenses are available, the most common in consumer-grade webcams being a plastic lens that can be manually moved in and out to focus the camera. Fixed-focus lenses, which have no provision for adjustment, are available; as a camera system's depth of field is greater for small image formats and is greater for lenses with a large f-number, the systems used in webcams have a sufficiently large depth of field that the use of a fixed-focus lens does not impact image sharpness to a great extent. Most models use manual focus. Digital video streams are represented by huge amounts of data, burdening its transmission and storage alike. Most if not all cheap webcams come with built-it ASIC to do video compression in real-time. Support electronics transmit it to the host computer; the camera pictured to the right, for example, uses a Sonix SN9C101 to transmit its image over USB. Each frame is transmitted uncompressed in RGB or YUV or compressed as JPEG; some cameras, such as mobile-phone cameras, use a CMOS sensor with supporting electronics "on die", i.e. the sensor and the support electronics are built on a single silicon chip to save space and manufacturing costs.
Most webcams feature built-in microphones to make video calling and videoconferencing more convenient. Typical interfaces used by articles marketed as a "webcam" are USB, Ethernet and IEEE 802.11. Further interfaces such as e.g. Composite video or S-Video are available; the USB video device class specification allows inter-connectivity of webcams to computers without the need for proprietary device drivers. Various proprietary as well as free and open-source software is available to handle the UVC stream. One could use GStreamer-based software to handle the UVC stream. Webcams are known for their low manufacturing cost and their high flexibility, making them the lowest-cost form of videotelephony; as webcams evolved with display technologies, USB interface speeds and broadband internet speeds, the resolution went up from 320×240, to 640×480, some offering 1280×720 or 1920×1080 resolution. Despite the low cost, the resolution offered as of 2019 is impressive, with now the low-end webcams offering resolutions of 720p, mid-range webcams offering 1080p resolution, high-end webcams offering 4K resolution at 60 fps.
Webcams have become a source of security and privacy issues, as some built-in webcams can be remotely activated by spyware. To address this concern, many webcams come with a physical lens cover; the most popular use of webcams is the establishment of video links, permitting computers to act as videophones or videoconference stations. Other popular uses include security surveillance, computer vision, video broadcasting, for recording social videos; the video streams provided by webcams can be used for a number of purposes, each using appropriate software: Most modern webcams is capable of capturing arterial pulse rate by the use of a simple algorithmic trick. Researchers claim. Webcams may be installed at places such as childcare centres, offices and private areas to monitor security and general activity. Webcams have been used for augmented reality experiences online. One such function has the webcam act as a "magic mirror" to allow an online shopper to view a
Otto I, called the Redhead, was Duke of Bavaria from 1180 until his death. He was called Otto VI as Count Palatine of Bavaria from 1156 to 1180, he was the first Bavarian ruler from the House of Wittelsbach, a dynasty which reigned until the abdication of King Ludwig III of Bavaria in the German Revolution of 1918. Duke Otto I was born at Kelheim, the son of Count Palatine Otto IV of Wittelsbach and Heilika of Pettendorf-Lengenfeld, a grandson of the Hohenstaufen duke Frederick I of Swabia, he was the brother of Archbishop Conrad I of Salzburg. Upon the death of his father in 1156, he succeeded him as Count palatine of the Bavarian duchy under the rule of Henry the Lion, a scion of the Welf dynasty; as one of the best knights in the employ of Emperor Frederick Barbarossa in 1155 he had prevented a defeat of the Emperor near Verona, where the army caravan was ambushed on the way back to Germany after the coronation at Rome. In the Dominium mundi conflict between emperor and pope culminating at the 1157 Reichstag of Besançon, fiery Otto could only be kept from smiting the papal legate Cardinal Rolando Bandinelli with his battleaxe by the personal intervention of Frederick.
He was rewarded with the duchy of Bavaria on 16 September 1180 at Altenburg in Thuringia, after the deposition of Duke Henry the Lion. But he was so little regarded by many of the Bavarian aristocracy that they are said to have refused him the customary homage, they went so far as to refuse to attend his first court assembly at Regensburg. With the separation of Styria under Duke Ottokar IV in the same year, Bavaria lost the last of her southeastern territories. With the support of the emperor and his brother Conrad, Otto was able to secure the rule of his dynasty from the wary Bavarian nobility, his descendants ruled Bavaria for the next 738 years. In 1182 or 1183, Duke Otto bought Dachau castle, the ministeriales, all other appurtenances for a large sum of cash from the widow of the last duke of Dachau and Merania, Conrad II, Duke of Merania. In 1183 Otto accompanied Emperor Frederick to sign the Peace of Constance with the Lombard League and died on the way back at Pfullendorf in Swabia, he was succeeded by his only surviving son Louis.
Otto's mortal remains are buried in the crypt of Scheyern Abbey. About 1169 Otto married a daughter of Count Louis I of Loon. Agnes and Otto had the following children: Otto Ulrich Agnes Heilika I, married in 1184 to Hallgrave Dietrich of Wasserburg Agnes, married Count Henry of Plain Richardis, married in 1186 to Count Otto I of Guelders and Zutphen Louis I, married in 1204 to Ludmilla of Bohemia Heilika II, married Count Adelbert III of Dillingen Elisabeth, married Count Berthold II of Vohburg Mechtild, married in 1209 to Count Rapoto II of Ortenburg. Sophia, married Landgrave Hermann I of Thuringia Citations Bibliography
Hugo Gernsback was a Luxembourgish-American inventor, writer and magazine publisher, best known for publications including the first science fiction magazine. His contributions to the genre as publisher—although not as a writer—were so significant that, along with the novelists H. G. Wells and Jules Verne, he is sometimes called "The Father of Science Fiction". In his honour, annual awards presented at the World Science Fiction Convention are named the "Hugos". Gernsback was born in 1884 in Luxembourg City, to Berta, a housewife, Moritz Gernsbacher, a winemaker, his family was Jewish. Gernsback emigrated to the United States in 1904 and became a naturalized citizen, he married three times: to Rose Harvey in 1906, Dorothy Kantrowitz in 1921, Mary Hancher in 1951. In 1925, he founded radio station WRNY, broadcast from the 18th floor of the Roosevelt Hotel in New York City. In 1928, WRNY aired some of the first television broadcasts. During the show, audio stopped and each artist waved or bowed onscreen.
When audio resumed, they performed. Gernsback is considered a pioneer in amateur radio. Before helping to create science fiction, Gernsback was an entrepreneur in the electronics industry, importing radio parts from Europe to the United States and helping to popularize amateur "wireless". In April 1908 he founded Modern Electrics, the world's first magazine about both electronics and radio, called "wireless" at the time. While the cover of the magazine itself states it was a catalog, most historians note that it contained articles and plotlines, qualifying it as a magazine. Under its auspices, in January 1909, he founded the Wireless Association of America, which had 10,000 members within a year. In 1912, Gernsback said that he estimated 400,000 people in the U. S. were involved in amateur radio. In 1913, he founded a similar magazine, The Electrical Experimenter, which became Science and Invention in 1920, it was in these magazines that he began including scientific fiction stories alongside science journalism—including his novel Ralph 124C 41+ which he ran for 12 months from April 1911 in Modern Electrics.
He died at Roosevelt Hospital in New York City on August 19, 1967. Gernsback provided a forum for the modern genre of science fiction in 1926 by founding the first magazine dedicated to it, Amazing Stories; the inaugural April issue comprised a one-page editorial and reissues of six stories, three less than ten years old and three by Poe and Wells. He said he became interested in the concept after reading a translation of the work of Percival Lowell as a child, his idea of a perfect science fiction story was "75 percent literature interwoven with 25 percent science". He played an important role in starting science fiction fandom, by organizing the Science Fiction League and by publishing the addresses of people who wrote letters to his magazines. Fans began to organize, became aware of themselves as a movement, a social force, he created the term "science fiction", though he preferred the term "scientifiction". In 1929, he lost ownership of his first magazines after a bankruptcy lawsuit. There is some debate about whether this process was genuine, manipulated by publisher Bernarr Macfadden, or was a Gernsback scheme to begin another company.
After losing control of Amazing Stories, Gernsback founded two new science fiction magazines, Science Wonder Stories and Air Wonder Stories. A year due to Depression-era financial troubles, the two were merged into Wonder Stories, which Gernsback continued to publish until 1936, when it was sold to Thrilling Publications and renamed Thrilling Wonder Stories. Gernsback returned in 1952–53 with Science-Fiction Plus. Gernsback was noted for sharp business practices, for paying his writers low fees or not paying them at all. H. P. Lovecraft and Clark Ashton Smith referred to him as "Hugo the Rat"; as Barry Malzberg has said: Gernsback's venality and corruption, his sleaziness and his utter disregard for the financial rights of authors, have been well documented and discussed in critical and fan literature. That the founder of genre science fiction who gave his name to the field's most prestigious award and, the Guest of Honor at the 1952 Worldcon was pretty much a crook has been established. Jack Williamson, who had to hire an attorney associated with the American Fiction Guild to force Gernsback to pay him, summed up his importance for the genre: At any rate, his main influence in the field was to start Amazing and Wonder Stories and get SF out to the public newsstands—and to name the genre he had earlier called "scientifiction."
Frederik Pohl said in 1965 that Gernsback's Amazing Stories published "the kind of stories Gernsback himself used to write: a sort of animated catalogue of gadgets". Gernsback's fiction includes the novel Ralph 124C 41+. Though Ralph 124C 41+ has been described as pioneering many ideas and themes found in SF work, it has been neglected due to what most critics deem poor artistic quality. Author Brian Aldiss called the story a "tawdry illiterate tale" and a "sorry concoction", while author and editor Lester del Rey called it "simply dreadful." While most other modern critics have little positive to say about the story's writing, Ralph 124C 41+ is considered by science fiction critic Gary Westfahl as "essential text for all studies of science fiction."Gernsback's second novel, Baron Münchausen's Scientific Adventures, was ser