Unreferenced date August 2009 A Bitstream or 1 bit DAC is a consumer electronics marketing term describing an oversampling digital to analog converter DAC with an actual 1 bit DAC that is, a simple on off switch in a Delta sigma modulation delta sigma loop operating at multiples of the sampling frequency . The combination is equivalent to a DAC with a larger number of bits usually 16 20 . The advantages of this type of converter are high linearity combined with low cost, owed to the fact that most of the processing takes place in the digital domain and requirements for the analog anti aliasing filter after the output can be relaxed. For these reasons, this design is very popular in digital consumer electronics CD DVD players, set top boxes and the like . See also Digital to Analog Converter DAC types DAC Types Category Electronics terms Category Consumer electronics Category Digital media ... more details
Jagged Edge may refer to Jagged Edge band , an American R&B singing group Jagged Edge Jagged Edge album Jagged Edge Jagged Edge album , 2006 Jagged Edge film Jagged Edge film , a 1985 film starring Glenn Close, Jeff Bridges, Robert Loggia and Peter Coyote Jagged Edge Gary Numan album Jagged Edge Gary Numan album , 2008 Jagged Edge, a British rock group whose members went on to form the band Skin British band Skin See also Jaggies , the informal name for aliasing artifacts in raster images disambiguation ... more details
sampling bandwidth creates a sonic artifact known as an aliasing alias , and the resulting distortion of the sound is termed aliasing . Examples of aliasing can be heard in early music Sampler musical ... Aliasing is a major concern in the analog to digital conversion of video and audio signals. In the creation ... more details
Unreferenced date December 2006 Orphan date February 2009 A Rural Mail Box or RMB is an artificial address that is created by Australia Post to deliver mail to a rural or remote location. The RMB address allows a sender or recipient of mail to succinctly specify the mail s destination. Without the RMB system, many intended destinations would otherwise be specifiable only by a series of directions or some other unwieldy, abstract description. The RMB address functions similarly to a post office box in that it describes an intended addressee with a unique number, but it is different in that it Aliasing computing aliases a real physical address rather than a container at a post office. Category Postal system of Australia Postal stub Australia stub ... more details
Unreferenced date June 2008 Context date October 2009 In image processing , stairstep interpolation is a general method for interpolating the pixels after enlarging an image. The key idea is to interpolate multiple times in small increments using any interpolation algorithm that is better than nearest neighbor interpolation , such as bilinear interpolation , and bicubic interpolation . A common scenario is to interpolate an image by using a bicubic interpolation which increases the image size by no more than 10 110 of the original size at a time until the desired size is reached. See also Anti aliasing B zier surface Cubic Hermite spline , the one dimensional analogue of bicubic spline Lanczos resampling Sinc filter Spline interpolation External links http www.imphotography.com downloads ssimagesize.htm Photoshop plugin to achieve stairstep interpolation Category Image processing ... more details
Multiple issues orphan February 2009 notability January 2009 GLTT is a Computer library library that allows OpenGL applications to read and draw TrueType fonts. The library supports Bitmapped font bitmapped and Anti aliasing anti aliased font rendering . Besides that, it also supports vectorized and polygonized drawing. ref Cite web url http gltt.sourceforge.net about.html title About This Site publisher GLTT accessdate 21 February 2011 ref References reflist External links Official website http gltt.sourceforge.net computer stub date January 2009 DEFAULTSORT Gltt Category Computer libraries ... more details
distinguish Nyquist rate File Aliasing folding.png thumb 400px The black dots are aliases of each other. The solid red line is an u example u of adjusting amplitude vs frequency. The dashed red lines are the corresponding paths of the aliases. The Nyquist frequency , named after the Swedish American engineer Harry Nyquist or the Nyquist Shannon sampling theorem , is half the sampling frequency of a discrete signal processing system. ref cite book title Probability and Statistics The Harald Cram r Volume first Ulf last Grenander authorlink Ulf Grenander publisher Wiley year 1959 url http books.google.com books?id UPc0AAAAMAAJ&q 22nyquist frequency 22 date 0 1965&dq 22nyquist frequency 22 date 0 1965&pgis 1 quote The Nyquist frequency is that frequency whose period is two sampling intervals. ref ref cite book title Aerospace Telemetry author Harry L. Stiltz publisher Prentice Hall year 1961 url http books.google.com books?id cro8AAAAIAAJ&q 22nyquist frequency 22 date 0 1965&dq 22nyquist frequency 22 date 0 1965&pgis 1 quote the existence of power in the continuous signal spectrum at frequencies higher than the Nyquist frequency is the cause of aliasing error ref It is sometimes known as the Aliasing Folding folding frequency of a sampling system. ref Cite web coauthors Thomas Zawistowski, Paras Shah title An Introduction to Sampling Theory url http www2.egr.uh.edu glover applets Sampling ... theorem shows that aliasing can be avoided if the Nyquist frequency is greater than the bandwidth ... length , such as cycles per meter. The aliasing problem In theory, a Nyquist frequency just .... Some amount of aliasing is unavoidable. Signal frequencies higher than the Nyquist frequency ... is not adequate. Both types of aliasing can be important. When attainable filters are used, some degree of oversampling is necessary to accommodate the practical constraints on anti aliasing filter ... represent. If the chosen anti aliasing filter a low pass filter in this case has a transition ... more details
rate would become lower than the nyquist requirement and then cause the aliasing by being below the nyquist minimum. Note that the anti aliasing filter must be a low pass filter in downsampling. This is different ... to be considered along with the aliasing effects it will have. Realizable low pass filters ... out by the downsampler s low pass filter. Since both interpolation and anti aliasing filters are low ... more details
Cleanup date May 2008 Unreferenced date December 2010 A polyphase quadrature filter , or PQF , is a filter bank which splits an input signal into a given number N mostly a power of 2 of equidistant sub band s. These sub bands are subsampled by a factor of N, so they are critically sample signal sampled . This critical sampling introduces aliasing . Similar to the Modified discrete cosine transform MDCT time domain alias cancellation the aliasing of polyphase quadrature filters is canceled by neighbouring sub bands, i.e. signals are typically stored in two sub bands. Note that signal in odd subbands is stored frequency inverted . PQF filters are used in MPEG 1 Audio Layer I and MPEG 1 Audio Layer II II , Musepack which was based on MPEG 1 layer II , in MP3 MPEG 1 Layer III with an additional MDCT, in MPEG 4 AAC SSR for the 4 band PQF bank, in Spectral Band Replication MPEG 4 V3 SBR for the analysis of the upper spectral replicated band, and in Digital Theatre System DTS . PQF has an advantage over the very similar stacked quadrature mirror filter QMF . Propagation delay Delay and computational effort are much lower. A PQF filter bank is constructed using a base filter, which is a low pass filter low pass at fs 4N. This lowpass is modulated by N cosine functions and converted to N band pass filter band passes with a Bandwidth signal processing bandwidth of fs 2N. The base lowpass is typically a n? finite impulse response FIR filter with a length of 10 N ... 24 N taps. Note that it is also possible to build PQF filters using recursive infinite impulse response IIR filters. PQF filter parameter Computation There are different formulas possible. Most of them are based on the modified discrete cosine transform MDCT but are slightly modified. Storing of frequencies in subbands Example for N 32 and fs 32 kHz. ... External links ... signal processing stub Category Digital signal processing Category Linear filters ... more details
bus. Other architectural changes include improvements to anti aliasing functionality. Previous GeForce chips could perform only super sampled anti aliasing, a demanding process that renders ... adds multi sampling and Quincunx anti aliasing methods, both of which perform significantly better ... aliasing is enabled the GeForce 3 is clearly superior because of its improvements in anti aliasing ... to it. GeForce 3 also has multi sampling anti aliasing support, a feature not available with the Radeon ... vertex and pixel shader s, hardware anti aliasing and DVD playback. Proper dual monitor support ... more details
Deleted image removed Image Artifact.png thumb right Artifacts caused by poor signal strength on KYW TV deletable image caption 1 Thursday, 10 September 2009 File HyperGridDigitalArtifacts.jpg thumb A complicated grid pattern is insufficiently processed by a smartphone camera. Image AproposAutismGlitchArt.jpg thumb 200px An electronic billboard is transformed in camera. A digital Artifact error artifact is any undesired alteration in data introduced in a digital process by an involved technique and or technology. Possible causes Hardware malfunction In computer graphics, visual artifact s may be generated whenever a hardware component such as the processor, memory chip, cabling malfunctions, etc. causing data corruption. Malfunction may be caused by physical damage, overheating, insufficient voltage sometimes due to GPU overclocking , etc. Common types of hardware artifacts are Texture mapping texture corruption and T vertices in 3D graphics, and pixelization in MPEG compressed video. Software malfunction Similarly to hardware malfunction, artifacts may be caused by software issues such as bugs in the algorithms, such as decoding encoding introducing artifacts into audio or video, or a poor pseudo random number generator would introduce artifacts into statistical research models. Compression artifact Compression Controlled amounts of unwanted information may be generated as a result of the use of lossy compression techniques. One of such cases are the artifacts seen in JPEG and MPEG compression algorithms. Aliasing Digital imprecision generated in the process of converting analog information into digital space due to the limited granularity of digital numbering space. In computer graphics, aliasing is seen as pixelation . Rolling shutter , the line scanning of an object which is moving too fast for the CMOS camera to capture a unitary image. External links http www.dpreview.com learn ? Glossary Digital Imaging Artifacts 01.htm DPReview Glossary Artifacts Category In ... more details
Blit can mean BL ock I mage T ransfer from Bit blit Bit Block Transfer , BitBLT , blitting etc. is a computer graphics operation in which two bitmap patterns are combined. Sometimes, this is done in hardware by means of a Blitter computer chip chip . The Blit computer terminal Blit terminal marketed as the AT&T 5620 is a programmable bitmap computer graphics graphics computer terminal terminal BLIT short story BLIT is a short story by David Langford . The Blit indigenous people Blit s are one of the indigenous people s of South Mindanao one of their immediate tribal neighbors is the Tboli . Thebit in brackets about the Tboli should remain until the article on the Blit people has been written, as it will add some context that is needed while tha article is blank. Also, does indigenous people in the article title need to be in brackets ie. Blit indigenous people . Band limited impulse train is a system used in Audio DSP. It is a popular technique to calculate aliasing free analog waveforms. disambig it Blit ... more details
Supersampling is an antialiasing technique, the process of eliminating jagged and pixelated edges aliasing . It is a method of smoothing images Rendering computer graphics rendered in computer games or other programs that generate imagery. Overview Image supersampling.png frame right Calculating the end color value Aliasing occurs because real world objects have continuous, smooth curves and lines, whereas monitors can only display discrete points of light called pixels . Since pixels are uniformly colored and always of the same shape, lines become jagged. Supersampling is one of the ways of solving this problem. Samples are taken at several instances inside the pixel not just at the center as default and an average color value is calculated. This is achieved by rendering the image at a much higher Display resolution resolution than the one being displayed, then downsampling shrinking it to the desired size, using the extra pixels for calculation. The result is smoother transitions from one line of pixels to another along the edges of objects. The number of samples determines the quality of the output . Computational cost and adaptive supersampling Supersampling is computationally expensive because it requires much greater video card memory and memory bandwidth , since the amount of Buffer computer science buffer used is several times larger. A way around this problem is adaptive supersampling . This works by acknowledging that very few pixels will actually be on a boundary, therefore only these need to be supersampled. At first only a few samples are made within a pixel. If these values are very similar, only these samples are used for determining color. If not, more are used. The result of this method is that a higher number of samples are calculated only where necessary ... nature of sampling, aliasing can still occur if a low number of sub pixels is used. Random ... Multisample anti aliasing Quincunx Graphics card Graphics processing unit Ray tracing graphics Framebuffer ... more details
Infobox software name Libart developer Raph Levien operating system Cross platform genre Graphics library license GNU Lesser General Public License LGPL or GNU General Public License GPL website http www.levien.com libart levien.com Libart is a free software graphics library with a vector based Application programming interface API . Cairo graphics Cairo obsoletes almost all uses of Libart. Notable usage GNOME Canvas uses Libart as its rendering API. GIMP uses Libart for vector rendering. Dia software Dia can use Libart for Anti aliasing antialiasing and Portable Network Graphics PNG export. See also Portal Free software Cairo graphics Graphics Device Interface GDI Quartz 2D External links http www.levien.com libart Libart levien.com http www.gnome.org mathieu libart libart.html The libart library gnome.org Category Graphics libraries Category X based libraries Category GNOME Category GTK compu graphics stub uk Libart ... more details
Orphan date February 2009 In the design of programming language s, an erroneous program is one whose semantics are not well defined, but where the language implementation is not obligated to signal an error either at compile or at execution time. For example, in Ada programming language Ada In addition to bounded errors, the language rules define certain kinds of errors as leading to erroneous execution. Like bounded errors, the implementation need not detect such errors either prior to or during run time. Unlike bounded errors, there is no language specified bound on the possible effect of erroneous execution the effect is in general not predictable. ref Ada Reference Manual ISO IEC 8652 1995 E http www.adaic.org standards 1zrm RM Final.pdf pdf , section 1.1.5. ref Defining a condition as erroneous means that the language implementation need not perform a potentially expensive check e.g. that a global variable aliasing computing refers to the same object as a subroutine parameter but may nonetheless depend on a condition being true in defining the semantics of the program. Notes references prog lang stub Category Programming language design ... more details
to prevent aliasing. Noble identities The Noble identities describe the effect of interchanging sampling ... as math H k z math .i See also Sampling information theory Aliasing Cascaded integrator comb filter ... more details
Frequency ambiguity resolution is used to find true target velocity for medium pulse repetition frequency PRF radar systems. Image AliasingSines.svg right thumb Doppler signal sampled with a pulse rate near the Doppler frequency. This is used with pulse Doppler radar . Definition Radial velocity aliasing occurs when reflections arrive from reflectors moving fast enough for the Doppler frequency to exceed the pulse repetition frequency PRF . Frequency ambiguity resolution is required to obtain the true radial velocity when the measurements is made using a system where the following inequality is true. math Radial Velocity 0.5 left frac PRF times C Transmit Frequency right math The radial velocity measurements made in this way produce a modulo function of the true radial velocity. math Apparent Velocity True Velocity MOD left frac PRF times C 2 times Transmit Frequency right math Theory Radar pulsing causes a phenomenon called Aliasing Sampling sinusoidal functions aliasing , which occurs when the Doppler frequency created by reflector motion exceeds the pulse repetition frequency PRF ref Cite web url http www.cage.curtin.edu.au mechanical info vibrations tut3.htm title Sampling and Aliasing publisher Curtin University of Technology ref . This concept is related to range ambiguity resolution . Doppler frequency shift is introduced onto reflected signals used by radar. Operation When the Doppler frequency shift exceeds the PRF, the frequency is reduced. This limitation is called the Nyquist rate Nyquist sampling rate . This introduces a Modular arithmetic modulo operation onto the apparent frequency of the reflected signal. The ambiguous velocity is as follows. math Ambiguous Velocity 0.5 left frac Doppler Frequency times C Transmit Frequency right math Frequency is folded for high speed targets where radial velocity produces a frequency shift above the Nyquist frequency . The true speed of the target may be folded by a modulo operation produced by the sampling process ... more details
Photo to Movie is slideshow software developed by LQ Graphics, Inc. that runs on Mac OS and Windows. It produces photo slideshow s. Overview Photo to Movie slideshow software is one of the original slideshow applications providing the Ken Burns effect. Originally created in 2002, it preceded the Ken Burns effect in iMovie by a few years. The video files it produces can be used online or burned to DVD. The application provides tools for adding motion effects aka the Ken Burns effect , transitions, layouts, backgrounds, titles, graphics, and music. It includes a specialized image processing algorithm to reduce or eliminate unwanted flickering aliasing effects that occur during Ken Burns motion effects. See also Slideshow Photo slideshow software Ken Burns effect External Links http www.lqgraphics.com software phototomovie.php Photo to Movie s official website http www.luminous landscape.com reviews software photo2movie.shtml Photo to Movie on Luminous Landscape http www.lafcpug.org reviews review photo2movie.html LAFCPUG Review Category Photo software Category Presentation ... more details
Infobox scientist name Franklin C. Crow image image size caption birth date birth place death date death place residence citizenship nationality ethnicity field Computer Science work institution University of Texas br Ohio State University br Xerox br PARC br Apple Computer Apple br Advanced Technology Group ATG br Interval Research br NVIDIA alma mater doctoral advisor doctoral students known for prizes religion footnotes Franklin C. Crow or Frank Crow is a computer scientist who has made important contributions to computer graphics , including some of the first practical anti aliasing techniques. Crow also proposed the shadow volume technique for generating geometrically accurate shadows. Interactive shadow volume rendering was popularized by the video game Doom 3 . Crow studied electrical engineering at the University of Utah University of Utah College of Engineering College of Engineering under Ivan Sutherland , a pioneer in computer graphics. He taught at the University of Texas and Ohio State University and was involved with research at Xerox PARC , Apple Computer s Advanced Technology Group , and Interval Research . From 2001 to 2008, he worked for NVIDIA as a GPU architect designing rasterization algorithms. Publications Parallel Computing for Graphics. Advances in Computer Graphics , 1990 113 140. Parallelism in rendering algorithms. in Graphics Interface 88, June 6 10, 1988, Edmonton, Alberta, Canada. p. 87 96 Advanced Image Synthesis Anti Aliasing. Advances in Computer Graphics , 1985 419 440. Advanced Image Synthesis Surfaces. Advances in Computer Graphics , 1985 457 467. Computational Issues in Rendering Anti Aliased Detail. COMPCON , 1982 238 244. Toward more complicated computer imagery. Computers & Graphics , 5 2 4 61 69 1980 . The Aliasing Problem in Computer Generated Shaded Images. Commun. ACM , 20 11 799 805 1977 . Shadow Algorithms for Computer Graphics , Computer Graphics SIGGRAPH 77 Proceedings , vol. 11, no. 2, 242 248. See also Universi ... more details
, aliasing may occur that is, frequencies at or above f sub s sub 2 may be erroneously reconstructed. See Aliasing for further discussion on this point. Interpolation as convolution sum The interpolation ... be zero at all frequencies equal to and above half the sample rate. See also Aliasing , Anti aliasing filter , Spatial anti aliasing Fourier transform Rectangular function Sampling signal ... more details
, alpha compositing , Z buffering Z Stencil buffer stencil buffering, and anti aliasing called Intelligent Memory , giving developers 4 sample anti aliasing at very little performance cost. 105 million ... Output unit s Maximum pixel fillrate 16 gigasamples per second fillrate using 4X multisample anti aliasing ... second using 4X anti aliasing 2 Z samples 8 ROPs 4X AA 500 MHz ref name Beyond3D Maximum anti aliasing ... more details
from the upper bound of the spectrum. See aliasing for a simpler formulation of this Nyquist criterion ... the gaps above that bound, in which aliasing will occur . Alternatively, for the case of a given sampling ..., and there s not room for stations at nearby expansion channels such as 87.9 without aliasing ... baseband alias under 56 MHz n 4 sampling, showing plenty of room for bandpass anti aliasing filter .... Note that if a band is sampled with n 1, then a band pass filter is required for the anti aliasing ... more details
Unreferenced date January 2011 Notability date January 2011 Infobox software name X Ray Engine logo image X ray logo.jpg 230px developer GSC Game World operating system Microsoft Windows platform Microsoft DirectX genre Game engine language English language English br Russian language Russian latest release version Version 1.6 latest release date Early 2010 frequently updated Updated when a new game comes out that supports the X Ray Engine programming language license website http www.gsc game.com The X Ray Engine is an engine created by Kiev based computer game developer, GSC Game World . Released on the 20th of March, 2007, the engine is used in the first three S.T.A.L.K.E.R. games released by the company, with a different engine being planned for the in development game S.T.A.L.K.E.R. 2. Introduction The X Ray Engine is a game engine, supporting DirectX 8.1 9.0c 10 10.1 11 and Shader Model 5.0. Up to a million polygons can be on screen at any one time. The engine features High dynamic range rendering HDR rendering , Parallax mapping parallax and normal mapping , soft shadows, motion blur, widescreen support, weather effects and day night cycles. As with other engines that utilize deferred shading , the X Ray Engine does not support anti aliasing and motion blur with enhanced dynamic lighting modes enabled. However, a fake form of anti aliasing can be enabled with the static lighting option this format utilizes a technique to blur the image to give the false impression of anti aliasing. Versions Version 1.0 Shadow of Chernobyl Version 1.5 Clear Sky Version 1.6 Call of Pripyat Engine used in S.T.A.L.K.E.R. Shadow of Chernobyl S.T.A.L.K.E.R. Clear Sky S.T.A.L.K.E.R. Call of Pripyat AI The X Ray Engine uses the proprietary ALife artificial intelligence engine developed by GSC Gameworld. ALife supports more than one thousand characters inhabiting the Zone the in game term for the 30 km wide area of exclusion surrounding the Chernobyl Nuclear Power Plant . These charac ... more details
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