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	CHANGING TIMES
		The simplest form of quantise (and the original reason for its existence in MIDI sequencers) is to move notes that are badly timed back onto the beat where they were intended to be.
		Quantising can make a great deal of difference to the feel of a track, but once you begin to move the hit points of one track very close to another, an interesting effect happens.
		Once you start hard quantising several instruments playing together, they will also tend to merge whenever their beats coincide, to produce a composite sound that is characterised by the attack of whichever instrument sounds first.
	www.soundonsound.com /sos/mar99/articles/Quant.html (3008 words)

	Dither and quantisation
		The effect of this on the digitised waveform is to generate unwanted frequencies, amounting to a distortion which is made particularly unpleasant by being harmonically unrelated to the wanted signal.
		The distortion to the waveform due to quantisation is clear, and obviously the vertical resolution is limited to the step sizes.
		Reducing the bit depth of a signal from 24 bits to 16 bits is essentially the same as sampling at 16 bits in the first place, and noise must be added at a level of half the new least significant bit.
	www.pearce.uk.com /papers/documents/dither.htm (695 words)

	Learn more about Gravity in the online encyclopedia. (Site not responding. Last check: 2007-11-05)
		Crucial experiments that justified the adoption of General Relativity over Newtonian gravity were the gravitational redshift, the deflection of light rays by the Sun, and the precession of the orbit of Mercury.
		Gravity is the only one of the four fundamental forces of nature that stubbornly refuses to be quantised (the other three: Electromagnetism, the Strong Force, and the Weak Force, can be quantised).
		Quantisation means that the force is measured in discrete steps that cannot be reduced in size, no matter what; alternatively, that gravitational interaction is transmitted by particles called gravitons.
	www.onlineencyclopedia.org /g/gr/gravity.html (1534 words)

	Introduction to Remotely Sensed Data - Data Resolution & Extent (Site not responding. Last check: 2007-11-05)
		Most remotely sensed imagery is recorded with quantisation levels in the range 0p;255, that is, the minimum 'detectable' radiation level is recorded as 0 while the 'maximum' radiation is recorded as 255.
		Quantisation levels are frequently given in terms of the number of bits rather than the number or range of levels.
		Since the radiometric resolution defines the maximum number of quantisation levels detectable by a sensor, it is most unlikely that a single remotely sensed image would actually contain data values covering the entire range.
	ceos.cnes.fr:8100 /cdrom/ceos1/irsd/pages/dre4.htm (712 words)

	Event Symmetric Space-Time
		It had been known since nearly the beginning of quantum theory that second quantisation was the way to construct quantum field theory, but this has always been regarded as a quirk rather than a fundamental feature.
		Quantisation as a formal process was introduced by Dirac as a generalisation of Heisenberg's mechanics of non-commuting matrices.
		Path integrals may give a clearer picture of what quantisation really is. Quantising a system which has different states seems to have something about all the different ways of going from A to B which are two different states of the system.
	www.weburbia.com /press/html/g09.htm (3600 words)

	Spectral Quantisation of Channel Vocoded Speech
		The tokens were quantised at the output of the analysis demodulation LP filters at 4 different j.n.d.
		The quantisation curves (at 1000 Hz) for the 4 j.n.d.
		It seems that the maximum degree of quantisation allowable before intelligibility and quality deterioration occurs is around 1 sone and that at the minimum intensity for which there appear to be significant cues (ie.
	www.shlrc.mq.edu.au /~rmannell/research/aix91 (2183 words)

	Genetic approach to scalar quantisation
		The scalar quantisation problem can be formulated as follows: for the probability distribution H(z), z from [a, b], find n representatives and n+1 breakpoints such that the mean-square error of quantisation is minimal.
		The classical algorithm for optimal quantisation (centroid algorithm)was developed in 1960 by J. Max, but the results are very sensitive to the initial state, and sometimes they are far from the global optimum.
		In the GA approach to the quantisation problem every individual (scalar quantiser) is represented as an ordered set of representatives - floating point values in the ascending order.
	www.mimuw.edu.pl /~jakubw/bib/a_po.html (662 words)

	Spectral Quantisation of Channel Vocoded Speech
		The tokens were quantised at the output of the analysis demodulation LP filters at 4 different j.n.d.
		These conditions can be considered the maximum levels of quantisation allowable before the intelligibility significantly deteriorates (at least for some classes) and they are also the coursest levels of quantisation that do not show a noticeable drop in speech quality.
		It seems that the maximum degree of quantisation allowable before intelligibility and quality deterioration occurs is around 1 sone and that at the minimum intensity for which there appear to be significant cues (ie.
	www.ling.mq.edu.au /~rmannell/research/aix91 (2120 words)

	Quantisation Noise
		Quantisation noise is the noise generated by the rounding error in the quantisation process.
		The diagram shows that the output value of the quantisation process remains constant as the input level increases until the next output value is reached.
		The quantisation error is relatively low and is not correlated with the signal.
	www.acoustics.salford.ac.uk /acoustics_world/de/adda/quantnoise.htm (367 words)

	Image Compression Techniques (Site not responding. Last check: 2007-11-05)
		Quantisation is in most cases not a reversible operation: therefore, it belongs to the so called 'lossy' methods.
		An optimum scalar quantiser was proposed by Lloyd and Max.
		These two operations constitute the logical modelling for this class of coding schemes; quantisation and encoding are strongly dependent on the statistical characteristics of the parameters of this approximation (and, therefore, on the approximation itself).
	www.ee.bgu.ac.il /~greg/graphics/compress.html (3695 words)

	AudioVideo101.com - Audio/Video Dictionary
		Quantisation takes the maximum amplitude or height of a given signal and divides it into a number of small pieces that are stacked on top of each other to reach the highest amplitude.
		If the quantisation blocks are smaller, say one eighth of an inch, then the approximated value is very close to the real value.
		In digital reproduction, quantisation is determined by the number of bits used to record the quantisation blocks.
	www.audiovideo101.com /dictionary/quantisation.asp (518 words)

	DSP Tutorial with MATLAB (Site not responding. Last check: 2007-11-05)
		Quantisation effects can be reduced by using more bits to represent each number, but this increases cost.
		In view of the significant effects on coefficient quantisation in Part 2, consider a parallel realisation of the filter design, using second order sections (and one 0th order section).
		These include data quantisation, which effectively adds noise to the signal being filtered, and data scaling, which must be arranged to prevent overflow in fixed-point additions.
	www.itr.unisa.edu.au /cbt/dsp/prac96.html (738 words)

	[No title]
		Quantisation, a form of entropy coding, is then used with non-uniform quantisation levels.
		Quantisation reduces the number of values a coefficient can take (it introduces quantisation noise here) and makes it more likely that adjacent coefficients are identical.
		Quantisation can also be used to control the bitrate of the output stream - fewer quantisation levels incareses the compression ratio since there is a reduction in the number of bits required to represent the levels.
	www.eee.bham.ac.uk /WoolleySI/video_on_demand/comp_16.htm (754 words)

	Perception: ECVP '98 abstracts (Site not responding. Last check: 2007-11-05)
		The results obtained for colour components of two natural textures showed that optimal quantisers on the red - green component are also uniform.
		Inside each spatial-frequency sub-band the measured quantisation parameters were constant for all textures used, showing, first, the uniformity of red - green quantisation laws and, second, a monotonic increase of blue - yellow quantisation parameters.
		Quantisation noise of red - green components must be equally distributed over its amplitude range, as opposed to blue - yellow noise which can be higher for high colour contrast.
	www.perceptionweb.com /ecvp98/l33b.html (358 words)

	1 JPEG Overview (Site not responding. Last check: 2007-11-05)
		To quantise the output of the DCT we divide this matrix by an integer matrix of the same dimensions.
		This is implemented by choosing the quantisation factors appropriately for the coefficient to be quantised.
		Hence two different quantisation factor tables are generally defined for colour images, one for the Y (or brightness) component, and one for the Cb and Cr components (or chrominance).
	murray.newcastle.edu.au /users/students/2000/c9425349/section3.htm (4500 words)

	Chapter 4 The Indexing Scheme
		Although these quantised images are likely to be difficult to identify by human eyes, this operation merely changed the "aspect ratios" of these quantised image shown in Figure 4.10(b).
		Since the indexing scheme involves the transformation of image quantisation, which actually reduces the resolution of the original images to represent "spatial information", there is a need for discuss the issue of the influence of image resolution versus image information content.
		That is, the quantised images may be used to distinguish similar images from dissimilar images for achieving the purpose of image retrieval.
	osiris.sunderland.ac.uk /~cs0sla/thesis/ch4_4.htm (1920 words)

	Lossy coding (Site not responding. Last check: 2007-11-05)
		Shorten supports two main types of lossy coding: the case where every segment is coded at the same rate; and the case where the bit rate is dynamically adapted to maintain a specified segmental signal to noise ratio.
		In the first mode, the variance of the prediction residual of the original waveform is estimated and then the appropriate quantisation performed to limit the bit rate.
		In areas of the waveform where there are strong sample to sample correlations this results in a relatively high signal to noise ratio, and in areas with little correlation the signal to noise ratio approaches that of the signal power divided by the quantisation noise of equation 22.
	svr-www.eng.cam.ac.uk /reports/ajr/TR156/node7.html (307 words)

	[No title]
		decoder and a lossless decoder is the presence of a quantiser.
		quantiser is to reduce the amount of psychovisual redundant data in the image.
		The quantisation level is directly proportional to the compression ratio.
	oldwww.cs.umu.se /tdb/kurser/TDBD07/VT-96/laborationer/GRP6/nm2.html (4948 words)

	[No title]
		Quantisation is the process of converting the sampled analogue signal (discrete-time continuous value) into impulses of discrete values of amplitude (analogous to the conversion from 'floating-point' values to 'integer' values in a program).
		quantisation noise: the noise introduced into a quantised signal by the approximation of the quantisation to the real analogue values.
		In a logarithmic quantisation scheme, the amplitude levels are further apart at large amplitudes and closer at smaller amplitudes, thereby giving a quantisation error which is proportional to the size of the signal at that instant.
	www.phon.ucl.ac.uk /courses/spsci/dsp/sample.html (874 words)

	Bores Signal Processing - Introduction to DSP - IIR filters - quantisation in IIR filters
		The effects of quantisation, saturation and overflow are all non linear, signal dependent errors.
		It is not possible to model the effects of quantisation in an IIR filter using simple random noise models.
		Some idea of quantisation effects in IIR filters can be gained using complex statistical models: but really the only way to evaluate the effects of quantisation in an IIR filter is to:
	www.bores.com /courses/intro/iir/5_quant.htm (463 words)

	Glossary of PA Terms - Q
		A measure of the width of the range of frequencies that are affected by a peaking equalisation control, in proportion to the equaliser's centre frequency.
		The added noise that results from the inaccuracy inherent in the assignment of a discrete numerical value to each instantaneous sample of an analogue signal, during analogue to digital conversion.
		Quantisation noise may sometimes be referred to as 'quantisation distortion', but is not a form of distortion in the true sense.
	www.btinternet.com /~paformusic/gl_q.htm (1109 words)

	VideoReDo Plus MPEG2 Edit and MPEG Editor Specifications
		The quantisation process refers to the DCT coefficients and is performed in order to both remove the subjective redundancy and control the compression factor.
		The setting of the quantisation parameters is a key point for the quality of the coder.
		Each element of a quantisation matrix refers to a coefficient of the Discrete Cosine Transform and it should be proportional to the subjective redundancy of that coefficient.
	www.videoredo.com /definitions/Q.htm (399 words)

	Contents of Vector Quantisation
		They can also be used with continuous signals such as speech by quantising each speech vector to give a unique VQ symbol for each input frame.
		However, the use of vector quantisation introduces errors and it can lead to rather fragile systems.
		This is done using the tool HC to read in and vector quantise each speech file.
	www.icsi.berkeley.edu /speech/docs/HTKBook/node83_ct.html (654 words)

	The Dirac Algorithm: Subband Quantisation (Site not responding. Last check: 2007-11-05)
		Having transformed the component data, each subband's coefficients are quantised by Dirac using a so-called uniform dead-zone quantiser.
		A simple uniform quantiser is a division of the real line into equal-width bins, of size equal to the quantisation factor QF: the bins are numbered and a reconstruction value is selected for each bin.
		A uniform dead-zone quantiser is slightly different in that the bin containing zero is twice as wide.
	www.bbc.co.uk /rd/projects/dirac/documentation/algorithm/quantisation.htm (361 words)

	Practical Groove Quantisation in Digital Performer
		Groove quantisation is particularly appealing because it enables the composer to create or extrapolate, his/her own grooves from MIDI and audio parts.
		The original concept of groove quantisation and how it might be applied to a MIDI performance was developed by acoustic researcher Ernest Cholakis in the mid- and late 1990s.
		When you're quantising the beats of a soundbite, DP will adjust the position of the transients of the audio file according to the quantisation option, and it will time-compress or expand the soundbite in order to make up or reduce the space between transients.
	www.soundonsound.com /sos/aug05/articles/performertech.htm (3008 words)

	VI Quantisation
		The effects of quantisation error are in fact both non linear and signal dependent.
		The model of quantisation as injections of random noise is helpful in gaining an idea of the effects.
		The effect of quantisation error is often similar to an injection of random noise.
	www.stcsm.gov.cn /learning/lesson/xinxi/20010705-1/20010705-6.asp (864 words)

	BROADCASTPAPERS.COM (Site not responding. Last check: 2007-11-05)
		where di,i=1…M are the quantiser decision levels, ri are the corresponding reconstruction levels (with di £ ri £ di+1) and p(x) is the probability density function of the input signal x, here assumed to be a continuous function.
		Then, the quantisation noise power in the DCT domain can be estimated from this single 'activity' parameter together with the quantiser scale parameter q.
		Having accepted that a single parameter may suffice to account for the dependence of quantisation noise power on the probability distribution of the source data, we observe that it is unnecessary to impose a particular shape such as a Laplacian on the data and then attempt to fit the data to the model.
	www.broadcastpapers.com /sigdis/Snell&WilcoxQualityMeasure03.htm (940 words)

	AMV :: Topic - Quantisation and Quantisation Matrices: Redux
		The quantisation tables will be stored in the jpeg or mepg file for the decoder to use and they are the tool we use for simplifiying the data.
		Quantisation tables were chosen (in the jpeg form, particularly) mainly by people deciding which looked the nicest with natural images.
		So, the tmpeg quantisation matrices for animation/cg are all 16s for the keyframes and all 32s for the delta frames in order to treat the quantisation equally for all the possible spatial frequencies.
	www.animemusicvideos.org /phpBB/viewtopic.php?t=46273 (1396 words)

	Quantisation
		The second stage in the analogue to digital conversion process is quantisation.
		The number of bits used to represent the sample governs the number of quantisation levels.
		Where n is the number of bits in the quantiser.
	www.acoustics.salford.ac.uk /acoustics_world/audiotutorial/adda/quantise.htm (137 words)

	Chapter 3: Voice communication (Site not responding. Last check: 2007-11-05)
		In general, the purpose of quantisation is to represent a sample by an N-bit value.
		With uniform quantisation, the range of possible values is divided into 2N equally sized segments and with each segment, an N-bit value is associated.
		At the start of the chapter we saw what sampling and quantisation is. It was also mentioned that a higher sampling rate and a smaller quantisation step implied a better representation of the original signal.
	research.edm.luc.ac.be /jori/thesis/onlinethesis/chapter3.html (2660 words)

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