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Frame Rate
Frame rate (expressed in or FPS) is the frequency (rate) at which consecutive images (frames) are captured or displayed. The term applies equally to film and video cameras, computer graphics, and motion capture systems. Frame rate may also be called the , and be expressed in hertz. Frame rate in electronic camera specifications may refer to the maximal possible rate, where, in practice, other settings (such as exposure time) may reduce the frequency to a lower number. Human vision The temporal sensitivity and resolution of human vision varies depending on the type and characteristics of visual stimulus, and it differs between individuals. The human visual system can process 10 to 12 images per second and perceive them individually, while higher rates are perceived as motion. Modulated light (such as a computer display) is perceived as stable by the majority of participants in studies when the rate is higher than 50 Hz. This perception of modulated light as steady is known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency
Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is equal to one event per second. The period is the interval of time between events, so the period is the reciprocal of the frequency. For example, if a heart beats at a frequency of 120 times a minute (2 hertz), the period, —the interval at which the beats repeat—is half a second (60 seconds divided by 120 beats). Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light. Definitions and units For cyclical phenomena such as oscillations, waves, or for examples of simple harmonic motion, the term ''frequency'' is defined as the number of cycles or vibrations per unit of time. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Movie Projector
A movie projector is an optics, opto-mechanics, mechanical device for displaying Film, motion picture film by projecting it onto a movie screen, screen. Most of the optical and mechanical elements, except for the illumination and sound devices, are present in movie cameras. Modern movie projectors are specially built video projectors. (see also digital cinema) Many projectors are specific to a particular film gauge and not all movie projectors are film projectors since the use of film is required. Predecessors The main precursor to the movie projector was the magic lantern. In its most common setup it had a concave mirror behind a light source to help direct as much light as possible through a painted glass picture slide and a lens, out of the lantern onto a screen. Simple mechanics to have the painted images moving were probably implemented since Christiaan Huygens introduced the apparatus around 1659. Initially candles and oil lamps were used, but other light sources, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temporal Resolution
Temporal resolution (TR) refers to the discrete resolution of a measurement with respect to time. Physics Often there is a trade-off between the temporal resolution of a measurement and its spatial resolution, due to Heisenberg's uncertainty principle. In some contexts, such as particle physics, this trade-off can be attributed to the finite speed of light and the fact that it takes a certain period of time for the photons carrying information to reach the observer. In this time, the system might have undergone changes itself. Thus, the longer the light has to travel, the lower the temporal resolution. Technology Computing In another context, there is often a tradeoff between temporal resolution and computer storage. A transducer may be able to record data every millisecond, but available storage may not allow this, and in the case of 4D PET imaging the resolution may be limited to several minutes. Electronic displays In some applications, temporal resolution may instead ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engadget
''Engadget'' ( ) is a multilingual technology blog network with daily coverage of gadgets and consumer electronics. ''Engadget'' manages ten blogs four of which are written in English and six have international versions with independent editorial staff. It has been operated by Yahoo since September 2021. History ''Engadget'' was founded by former '' Gizmodo'' technology weblog editor and co-founder Peter Rojas. ''Engadget'' was the largest blog in Weblogs, Inc., a blog network with over 75 weblogs, including ''Autoblog'' and ''Joystiq,'' which formerly included ''Hackaday''. Weblogs Inc. was purchased by AOL in 2005. Launched in March 2004, ''Engadget'' is updated multiple times a day with articles on gadgets and consumer electronics. It also posts rumors about the technological world, frequently offers opinion within its stories, and produces the weekly Engadget Podcast that covers tech and gadget news stories that happened during the week. On December 30, 2009, ''Engadget' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three-two Pull Down
Three-two pull down (3:2 pull down) is a term used in filmmaking and television production for the post-production process of transferring film to video. It converts 24 frames per second into 29.97 frames per second, converting approximately every four frames into five frames plus a slight slow down in speed. Film runs at a standard rate of 24 frames per second, whereas NTSC video has a signal frame rate of 29.97 frames per second. Every interlaced video frame has two fields for each frame. The three-two pull down is where the telecine adds a third video field (a half frame) to every second video frame, but the untrained eye cannot see the addition of this extra video field. In the figure, the film frames A–D are the true or original images since they have been photographed as a complete frame. The A, B, and D frames on the right in the NTSC footage are original frames. The third and fourth frames have been created by blending fields from different frames. Video 2:3 In the Un ... [...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] |
