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Spatial aliasing in the form of a Moiré pattern.
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Spatial and aliasing
Spatial aliasing, particular of angular frequency, can occur when reproducing a light field or sound field with discrete elements, as in 3D displays or wave field synthesis of sound.
Spatial and form
Spatial memories are said to form after a person has already gathered and processed sensory information about her or his environment.
* Spatial translation: These spatial symmetries are represented by transformations of the form and describe those situations where a property of the system does not change with a continuous change in location.
* Spatial inversion: These are represented by transformations of the form and indicate an invariance property of a system when the coordinates are ' inverted '.
Spatial and .
The necessary inference, as the authors themselves interpret it, would seem to be this: `` ( ( 1 ) Spatial qualities are not among those grasped by the sense of touch, as such.
Spatial planning and movement, speech production, and complex motor movements are all aspects of action.
The Bergeron and Spatial Synoptic Classification systems focus on the origin of air masses that define the climate of a region.
Spatial information can be stored in a database, from which it can be extracted on demand.
Spatial autocorrelation can also occur geographic areas are likely to have similar errors.
Spatial coherence typically is expressed through the output being a narrow beam which is diffraction-limited, often a so-called " pencil beam.
* Spatial performance: LCDs come in only one size for a variety of applications and a variety of resolutions within each of those applications.
** Optical solitons, An equilibrium solution for either an optical pulse ( temporal soliton ) or Spatial mode ( spatial soliton ) that does not change during propagation due to a balance between diffraction and the Kerr effect ( e. g. Self-phase modulation for temporal and Self-focusing for spatial solitons ).
Spatial indices are well suited for handling the complexity of Grid resource queries.
The U. S. Navy used a PDP-11 / 34 to control its Multi-station Spatial Disorientation Device, a simulator used in pilot training, until 2007, when it was replaced by a PC-based emulator that could run the original PDP-11 software and interface with custom Unibus controller cards.
Spatial subdivision methods, discussed below, try to achieve this.
Spatial categories vary greatly between languages and recent research has shown that speakers rely on the linguistic conceptualization of space in performing many quotidian tasks.
* Spatial Production Allocation Model, global rainfed and irrigated crop production and distribution spatially disaggregated at 10 km grid cells, developed by HarvestChoice.
) ( 1985 ): Social Relations and Spatial Structures.
Also of importance to the development of CAD was the development of the B-rep solid modeling kernels ( engines for manipulating geometrically and topologically consistent 3D objects ) Parasolid ( ShapeData ) and ACIS ( Spatial Technology Inc .) at the end of the 1980s and beginning of the 1990s, both inspired by the work of Ian Braid.
Place, Practice and Structure: Social and Spatial Transformation in Southern Sweden, 1750-1850.
Spatial measurements are used to quantify how far apart objects are, and temporal measurements are used to quantitatively compare the interval between ( or duration of ) events.
In their journal article " Beyond social capital: Spatial dynamics of collective efficacy for children ", Sampson et al.
; 3D PHL V5: 3D ACIS PHL V5 is a hidden line removal ( HLR ) solution from Spatial based on CATIA V5 technology.
ACIS is currently being developed by Spatial.
Spatial distribution of marine phytoplankton species is restricted both horizontally and vertically.
This plan would as one of it components include a Spatial Development Framework plan which would normally, certainly for the larger metropolitan areas, indicate an Urban Edge beyond which urban type development would be severely limited or restricted.
aliasing and form
If the waveform is digitally created directly in the time domain using a non-bandlimited form, such as y = x-floor ( x ), infinite harmonics are sampled and the resulting tone contains aliasing distortion.
A form of spatial aliasing can also occur in antenna arrays or microphone arrays used to estimate the direction of arrival of a wave signal, as in geophysical exploration by seismic waves.
The resulting stop-go motion is a temporal form of jaggies ; formally, a form of aliasing.
This form of oscillator sync is more common than soft sync, but is prone to generating aliasing in naive digital implementations.
A bootleg TS rarely, if ever, uses this form of synchronisation which can lead to additional temporal aliasing.
In the most common geometrical SR algorithms, the added information is embedded in the low resolution image in the form of aliasing.
aliasing and Moiré
Moiré patterns are often an undesired artifact of images produced by various digital imaging and computer graphics techniques, for example when scanning a halftone picture or ray tracing a checkered plane ( the latter being a special case of aliasing, due to undersampling a fine regular pattern ).
An example of spatial aliasing is the Moiré pattern one can observe in a poorly pixelized image of a brick wall.
The blur makes the image less sharp, but prevents the formation of Moiré pattern aliasing artifacts.
aliasing and pattern
The aliasing appears as a moiré pattern.
aliasing and .
Older techniques, such as bilinear and trilinear filtering, do not take into account the angle a surface is viewed from, which can result in aliasing or blurring of textures.
If a naive rendering algorithm is used without any filtering, high frequencies in the image function will cause ugly aliasing to be present in the final image.
In order to remove aliasing, all rendering algorithms ( if they are to produce good-looking images ) must use some kind of low-pass filter on the image function to remove high frequencies, a process called antialiasing.
Most printers already use such small pixels that aliasing is rarely a problem and, in any case, they don't have the addressable fixed subpixels ClearType requires.
This interpolation is not unique: aliasing implies that one could add N to any of the complex-sinusoid frequencies ( e. g. changing to ) without changing the interpolation property, but giving different values in between the points.
Note that if the operations are performed in a colour space where γ is not equal to 1 then the operation will lead to non-linear effects which can potentially be seen as aliasing artifacts ( or ' jaggies ') along sharp edges in the matte.
Another reason to be interested in S < sub > 1 / T </ sub >( ƒ ) is that it often provides insight into the amount of aliasing caused by the sampling process.
Decreasing N, causes overlap ( adding ) in the time-domain ( analogous to aliasing ), which corresponds to decimation in the frequency domain.
" Jaggies " is the informal name for artifacts in raster images, most frequently from aliasing, which in turn is often caused by non-linear mixing effects producing high-frequency components or missing or poor anti-aliasing filtering prior to sampling.
In some systems, such as the Digital Light Processing ( DLP ) system, there is no flying spot or raster scan at all, so there is no flicker other than that generated by the temporal aliasing of the film image capture.
Converting outlines requires filling them in ; converting to bitmaps is not trivial, because bitmaps often don't have sufficient resolution to avoid " stairstepping " (" aliasing "), especially with smaller visible character sizes.
This produces aliasing because the same vibration can be considered to have a variety of different wavelengths, as shown in the figure.
It is mathematically equivalent to the aliasing of a signal that is sampled at discrete intervals.
However, this solution may create undesirable aliasing artifacts wherever two elements overlap the same pixel.
The constructive proof of the theorem leads to an understanding of the aliasing that can occur when a sampling system does not satisfy the conditions of the theorem.
The error that corresponds to the failure of bandlimitation is referred to as aliasing.
A designer of a system that deals with sampling and reconstruction processes needs a thorough understanding of the signal to be sampled, in particular its frequency content, the sampling frequency, how the signal is reconstructed in terms of interpolation, and the requirement for the total reconstruction error, including aliasing, sampling, interpolation and other errors.
# Increase the sampling rate, to above twice some or all of the frequencies that are aliasing.
However, the leakage energy can be made small enough so that the aliasing effects are negligible.
Similar to one-dimensional discrete-time signals, images can also suffer from aliasing if the sampling resolution, or pixel density, is inadequate.
For example, a digital photograph of a striped shirt with high frequencies ( in other words, the distance between the stripes is small ), can cause aliasing of the shirt when it is sampled by the camera's image sensor.
The top image is what happens when the image is downsampled without low-pass filtering: aliasing results.
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