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Hanover Bars
Hanover bars, in one of the PAL television video formats, are an undesirable visual artifact in the reception of a television image. The name refers to the city of Hannover, in which the PAL system developer Telefunken Fernseh und Rundfunk GmbH was located. The PAL system encodes color as ''YUV''. The ''U'' (corresponding to ''B-Y'') and ''V'' (corresponding to ''R-Y'') signals carry the color information for a picture, with the phase of the ''V'' signal reversed (i.e. shifted through 180 degrees) on alternate lines (hence the name PAL, or ''phase alternate line''). This is done to cancel minor phase errors in the reception process. However, if gross errors occur, complementary errors from the ''V'' signal carry into the ''U'' signal, and thus visible stripes occur. Later PAL systems introduced alterations to ensure that Hanover bars do not occur, introducing a ''swinging burst'' to the color synchronization. Other PAL systems may handle this problem differently. Suppressio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hanover Bars With PAL Delay
Hanover (; german: Hannover ; nds, Hannober) is the capital and largest city of the German state of Lower Saxony. Its 535,932 (2021) inhabitants make it the 13th-largest city in Germany as well as the fourth-largest city in Northern Germany after Berlin, Hamburg and Bremen. Hanover's urban area comprises the towns of Garbsen, Langenhagen and Laatzen and has a population of about 791,000 (2018). The Hanover Region has approximately 1.16 million inhabitants (2019). The city lies at the confluence of the River Leine and its tributary the Ihme, in the south of the North German Plain, and is the largest city in the Hannover–Braunschweig–Göttingen–Wolfsburg Metropolitan Region. It is the fifth-largest city in the Low German dialect area after Hamburg, Dortmund, Essen and Bremen. Before it became the capital of Lower Saxony in 1946, Hannover was the capital of the Principality of Calenberg (1636–1692), the Electorate of Hanover (1692–1814), the Kingdom of Hannover (1814†... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video
Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) systems which, in turn, were replaced by flat panel displays of several types. Video systems vary in display resolution, aspect ratio, refresh rate, color capabilities and other qualities. Analog and digital variants exist and can be carried on a variety of media, including radio broadcast, magnetic tape, optical discs, computer files, and network streaming. History Analog video Video technology was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) television systems, but several new technologies for video display devices have since been invented. Video was originally exclusively a live technology. Charles Ginsburg led an Ampex research team developing one of the first practical vi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hannover
Hanover (; german: Hannover ; nds, Hannober) is the capital and largest city of the German States of Germany, state of Lower Saxony. Its 535,932 (2021) inhabitants make it the List of cities in Germany by population, 13th-largest city in Germany as well as the fourth-largest city in Northern Germany after Berlin, Hamburg and Bremen. Hanover's urban area comprises the towns of Garbsen, Langenhagen and Laatzen and has a population of about 791,000 (2018). The Hanover Region has approximately 1.16 million inhabitants (2019). The city lies at the confluence of the River Leine and its tributary the Ihme, in the south of the North German Plain, and is the largest city in the Hannover–Braunschweig–Göttingen–Wolfsburg Metropolitan Region. It is the fifth-largest city in the Low German dialect area after Hamburg, Dortmund, Essen and Bremen. Before it became the capital of Lower Saxony in 1946, Hannover was the capital of the Principality of Calenberg (1636–1692), the Electorat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telefunken
Telefunken was a German radio and television apparatus company, founded in Berlin in 1903, as a joint venture of Siemens & Halske and the ''Allgemeine Elektrizitäts-Gesellschaft'' (AEG) ('General electricity company'). The name "Telefunken" appears in: * the product brand name "Telefunken"; * ''Gesellschaft für drahtlose Telegraphie m.b.H., System Telefunken'', founded 1903 in Berlin as a subsidiary of AEG and Siemens & Halske; * ''Telefunken, Gesellschaft für drahtlose Telegraphie m.b.H.'' (from 1923 to 1955 – since 1941 subsidiary of the AEG only); * ''Telefunken GmbH'' in 1955; * ''Telefunken Aktiengesellschaft (AG)'' in 1963; * Merger of AEG and Telefunken to form ''Allgemeine Elektrizitäts-Gesellschaft AEG-Telefunken'' (from 1967 to 1979); * AEG-TELEFUNKEN AG (from 1979 to 1985); * ''TELEFUNKEN Fernseh und Rundfunk GmbH'', Hanover (1972, subsidiary of AEG-TELEFUNKEN); * Telefunken electronic GmbH (a spin-off of AEG-Telefunken and DASA * the company (since 1992 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase (waves)
In physics and mathematics, the phase of a periodic function F of some real variable t (such as time) is an angle-like quantity representing the fraction of the cycle covered up to t. It is denoted \phi(t) and expressed in such a scale that it varies by one full turn as the variable t goes through each period (and F(t) goes through each complete cycle). It may be measured in any angular unit such as degrees or radians, thus increasing by 360° or 2\pi as the variable t completes a full period. This convention is especially appropriate for a sinusoidal function, since its value at any argument t then can be expressed as \phi(t), the sine of the phase, multiplied by some factor (the amplitude of the sinusoid). (The cosine may be used instead of sine, depending on where one considers each period to start.) Usually, whole turns are ignored when expressing the phase; so that \phi(t) is also a periodic function, with the same period as F, that repeatedly scans the same range of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase (waves)
In physics and mathematics, the phase of a periodic function F of some real variable t (such as time) is an angle-like quantity representing the fraction of the cycle covered up to t. It is denoted \phi(t) and expressed in such a scale that it varies by one full turn as the variable t goes through each period (and F(t) goes through each complete cycle). It may be measured in any angular unit such as degrees or radians, thus increasing by 360° or 2\pi as the variable t completes a full period. This convention is especially appropriate for a sinusoidal function, since its value at any argument t then can be expressed as \phi(t), the sine of the phase, multiplied by some factor (the amplitude of the sinusoid). (The cosine may be used instead of sine, depending on where one considers each period to start.) Usually, whole turns are ignored when expressing the phase; so that \phi(t) is also a periodic function, with the same period as F, that repeatedly scans the same range of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chrominance
Chrominance (''chroma'' or ''C'' for short) is the signal used in video systems to convey the color information of the picture (see YUV color model), separately from the accompanying luma signal (or Y' for short). Chrominance is usually represented as two color-difference components: U = B′ − Y′ (blue − luma) and V = R′ − Y′ (red − luma). Each of these difference components may have scale factors and offsets applied to it, as specified by the applicable video standard. In composite video signals, the U and V signals modulate a color subcarrier signal, and the result is referred to as the chrominance signal; the phase and amplitude of this modulated chrominance signal correspond approximately to the hue and saturation of the color. In digital-video and still-image color spaces such as Y′CbCr, the luma and chrominance components are digital sample values. Separating RGB color signals into luma and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Saturation
Colorfulness, chroma and saturation are attributes of perceived color relating to chromatic intensity. As defined formally by the International Commission on Illumination (CIE) they respectively describe three different aspects of chromatic intensity, but the terms are often used loosely and interchangeably in contexts where these aspects are not clearly distinguished. The precise meanings of the terms vary by what other functions they are dependent on. * Colorfulness is the "attribute of a visual perception according to which the perceived color of an area appears to be more or less chromatic"., page 87. The colorfulness evoked by an object depends not only on its spectral reflectance but also on the strength of the illumination, and increases with the latter unless the brightness is very high ( Hunt effect). * Chroma is the "colorfulness of an area judged as a proportion of the brightness of a similarly illuminated area that appears white or highly transmitting". As a resu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dot Crawl
Dot crawl is a visual defect of color analog video standards when signals are transmitted as composite video, as in terrestrial broadcast television. It consists of moving checkerboard patterns which appear along horizontal color transitions (vertical edges). It results from intermodulation or crosstalk between chrominance and luminance components of the signal, which are imperfectly multiplexed in the frequency domain. The term is more associated with the NTSC analog color TV system, but is also present in PAL (see Chroma dots). Although the interference patterns are slightly different depending on the system used, they have the same cause and the same general principles apply. This takes two forms: chrominance interference in luminance (chrominance being interpreted as luminance), and luminance interference in chrominance. Dot crawl is most visible when the chrominance is transmitted with a high bandwidth, so that its spectrum reaches well into the band of frequencies used by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PAL-S
PAL-S is the system of television receiver sets in the early days of the PAL system. Here PAL stands for ''Phase alternating at line rate'' and S stands for ''simple''. PAL system The color hue modulates the phase of a subcarrier named color carrier. In PAL system the polarity of the phase in each frame is reversed to neutralize the undesirable phase shifts introduced during transmission. Thus the effect of undesirable phase shift is positive in one frame and negative in the second frame. Averaging the two, the effect of the undesirable phase shifts in two consecutive frames cancel each other. The PAL-S receiver In the early days of the PAL system, it was proposed that, the human eye can average the slightly different color hues in two consecutive frames and perceive the original color. The television receiver sets which rely on optical averaging were called PAL-S receivers. The problems in PAL-S However, it soon turned out that the optical averaging had problems. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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