interface: 1. The stairstepping appearance of diagonal lines and curves on a low resolution display. 2. A metallic distortion heard when digitized sounds are sampled at too low a rate, forcing the computer to fill in the gaps. In both cases, anti-aliasing resolves the problem by smoothing things out, sacrificing some detail in order to look or sound better.
Unwanted visual effects or artifacts caused by limited display resolution. These effects include grainy surfaces, jaggies (staircasing along diagonal lines), moiré effects (grids or checkerboards), or temporal aliasing (strobing) in animated scenes.They are controlled by anti-aliasing settings. See also anti-aliasing.
A form of image distortion associated with signal sampling. A common form of aliasing is a stair-stepped appearance along diagonal and curved lines. Also causes distortion to audio.
a artifact of a discrete sampling process when the signal being sampled contains frequencies higher that half the sampling frequency. This can lead to misleading data.
A jagged look of an image or type that happens when the resolution is inadequate or when images have been increased. The square pixels that make up the image are then visable to the naked eye. See also jaggies.
The misrepresentation of high frequencies from the original signal as low frequencies in the sampled result, due to undersampling. Aliasing distorts the letterforms and letter spacing.
A form of image distortion associated with signal sampling at low resolutions. The result is that diagonal lines appear stepped (like a staircase).
Interference phenomenon which occurs when a sampled signal contains frequencies that are higher than half the sampling frequency. A CCD samples the picture spatially. An optical low-pass filter is used to avoid aliasing, especially in color applications.
A jagged effect which occurs when a graphic image has low resolution
Is when a wider spaced line pattern is created from a finer line pattern. This is caused by improper filtering and/or insufficient resolution of the display relative to the source.
The jagged, stair-stepped features associated with a line on a computer monitor, usually only present when lines are not horizontal, vertical, or at a 45 degree angle. Aliasing occurs because picture elements (pixels) are arranged rectangularly in rows and columns on a display.
The generation of false signal frequencies caused by sampling at a rate lower than the Nyquist rate or two times the maximum signal frequency.
The pixelated or stair-step appearance of slanted or curved lines on low-resolution, computer generated images.
Defects in a picture caused by too low a sampling frequency or poor filtering. Usually called "jaggies" or stairsteps effect.
Undesirable signals added to and interfering with an originating electronic signal. In audio, frequencies generated by inadequate digital filter sampling circuitry, harmonically unrelated to the original signal. In video, display effects caused by too much high frequency video information. Examples are: Temporal aliasing - e.g., rotating wagon wheel spokes apparently reversing direction Raster scan aliasing - e.g., twinkling or strobing effects on sharp horizontal lines Stair-stepping - Stepped or jagged edges of angled lines, e.g., at the slanted edges of letters. (See ANTI-ALIASING)
Distortion caused by a low sample rate.
The familiar "staircase effect". Jagged transitions are often formed between adjacent pixels in the representation of diagonals or curves. These "jaggies" can be smoothed out by anti-aliasing.
The unwanted jagged, or stair stepping, appearance of diagonal lines in an image caused by the square shape of pixels. Aliasing is most often noticed in higher contrast areas of your photo.
The erroneous interpretation of high-frequency signals as lower-frequency signals. Such misinterpretations are an expected result of making discrete measurements with sampling devices such as analog-to-digital (A/D) converters. See also anti-aliasing filters.
A phenomenon encountered when sampling a continuous function to produce values at discrete points. If the sampling frequency isn't high enough to resolve the highest frequency signal present in the continuous function, then the high frequency information above the sampling frequency will appear as a false enhancement of (or, equivalently, be aliased onto) a related lower frequency in the computed power spectrum.
the phenomenon resulting from digitizing fewer than two samples per period in a periodic function. Aliasing can occur in MR imaging whenever the area of anatomy extends beyond the field of view. These areas extending beyond the field of view boundaries are aliased back into the image to appear at artifactual locations.
Unwanted visual effects caused by insufficient sampling resolution or inadequate filtering to completely define an object; most commonly seen as a jagged or stepped edge along object boundaries or along lines.
Jagged lines in a pixilated image.
Distortion in the video signal which may manifest itself in different ways, depending on the type of aliasing: Spectral aliasing is caused by interference between two frequencies, such as the luminance and chrominance frequencies or the chrominance and field scanning frequencies. It appears as moirè or herringbone patterns, straight lines that become wavy, or rainbow colors. Spatial aliasing is distortion that occurs because of limitations in physical resolution of the scanning process. It appears, for example, as straight diagonal lines that become stair stepped or jagged. Temporal aliasing is distortion resulting from information lost between line or field scans. It appears, for example, when a video camera is focused on a computer screen; the video output shows a flickering bar on the computer screen because of the lack of scan synchronization of the camera and the computer.
An effect that occurs when an analog signal is digitally sampled. See the graphical example of 44,100 Hz sampling [by coincidence, 44.1 kb]. Samples (black circles) of a 10,000 Hz tone are identical to samples of a 34,100 tone. In general, samples of a tone of frequency f are identical (except for a phase shift) to samples of a tone of frequency Fs - f, where Fs is the sampling rate. Thus if f equals, say Fs/2 + f0, the digital recording will produce a false tone of Fs/2 - f0. Anti-aliasing filters are used to eliminate tones above Fs/2 to avoid this effect. See the Signal Processing Section for more detail.
The jagged, "stair-stepped" edges that can appear between colors in a bitmapped graphic.
In computer graphics, the undesirable jagged or stair-stepped appearance of diagonal lines in computer-generated graphic images
Stair-stepping pattern on the diagonal lines of an image.
The jagged, stepped lines that appear on computer generated images, due to pixilation.
is the staircase or "jaggy" phenomenon brought about by the limitations of working with pixels. Because pixels are distinct points, smooth curves and diagonal lines are not possible.
A rendering technique that assigns to pixels the color of the primitive being rendered, regardless of whether that primitive covers all or only a portion of the pixel's area. This results in jagged edges, or jaggies.
A form of distortion which can occur during the conversion of analog signals into digital. If the input signal is more than one half the sampling rate, only portions of the signal will be present when the system samples the waveform. A false image of the waveform based on the components that were actually sampled, is created.
When computer graphics output has jagged edges or a stair stepped appearance when magnified. Homonym is "anti-aliasing".
Defects or distortion in a television picture or audio. In digital video, aliasing is caused by insufficient sampling or poor filtering of the digital video. Defects are typically seen as jagged edges on diagonal lines and twinkling or brightening.
The “jaggies,” those stair-stepping patterns that occur on a diagonal or curved line on a computer or video display. Can be smoothed or corrected through anti-aliasing processes.
Aliasing is a jagged edge on text and images
Distortion in a video image. In analog video, this is caused by interference between different signal frequencies; in digital video, it's caused by poor sampling in the digitizing process. On the screen, the result is that angled lines look jagged. Anti-Aliasing is the process of smoothing out those jagged lines.
The result of sampling an analog frequency signal at a rate below that required by the Nyquist theorem of 2 x Fs. Under-sampling translates high frequency components into the pass-band, producing unwanted signal components and unpredictable results.
() Condition when bitmapped or vector graphics showjagged edges under magnification.
Unwanted frequencies generated when sampling a signal with frequency more than half the sampling rate.
spatial aliasing creates visual artifacts such as jagged edges while temporal aliasing creates animation artifacts such as waggon wheels rotating backwards. Both are caused by insufficient sampling.
In computer graphics, an undesirable effect--also known as “jaggies”--in which the edge of the image or letter is characterized by a stair-step appearance.
Result when graphics, either constructed with lines (vector) or dots (bitmap), show jagged edges when magnified.
If frequencies above the Nyquist Frequency are not filtered out, energy in these will appear as spectral artefacts below the Nyquist Frequency. Optical and electronic anti aliasing can be used to prevent this. Sometimes the higher frequencies are said to be “folded” back so the term “folding” is used.
The effect on a signal when it has been sampled at less than twice its highest frequency.
Refers to the jagged appearance of diagonal and curved lines in a bit-mapped image.
envelope follower modulation depth sample rate
is the perception as noise of high-frequency sounds or visual components, due to insufficient sampling frequency. Proper filtering avoids aliasing.
A stair step effect (jaggies) caused by poor resolution in which angled lines or edges of elements in an electronic image look broken or crooked. Anti-aliasing programs smooth out these boundaries and produce a softer image.
A jagged effect in an image that caused by low resolution
Commonly referred to as "jaggies", these are the 'stair' patterns that appear on the edge of diagonal or curved lines on a computer or video display. They can usually be removed by an Anti-aliasing function.
In reflection mapping, a distortion in appearance resulting from two nearby vertices on a surface that have different normals, and therefore different texture images.
Is sampled data interference. This can happen in CCD image projection of high spatial frequencies. It can be lessened by a method known as optical low-pass filtering. Aliasing is also known as Moire patterning.
(1) (n.) The jagged artifact in a line or in the silhouette of a curve that results from drawing on a raster grid. Aliasing is especially noticeable in low-resolution monitors. Also called jaggies. See also antialiasing.(2) (n.) See command aliasing.
Aliasing is basically described as the tendency for a curved or diagonal line to appear jagged since they are composed of tiny squares, or pixels. Anti-aliasing remedies this jagged appearance through software, making images appear more smooth and natural. Video games may provide varying levels of anti-aliasing, and generally with higher levels of anti-aliasing, the overall performance of the game will be lower since more processing power is being dedicated to smoothing each image. For this reason, many graphics card reviews will show the effect on the frame rate of a game when run with different levels of anti-aliasing applied.
Aliasing occurs when smooth curves and lines become rough or jagged because of a lower resolution device, or by an event. In analog video, aliasing is typically caused by interference between the luma and chroma frequencies or between the chroma and field scanning frequencies. It appears as a moiré or herringbone pattern, straight lines that become wavy, or rainbow colors. (Also see cross color.) In digital video, insufficient sampling or poor filtering of the signal causes aliasing. Defects typically appear as jagged edges on diagonal lines and twinkling or brightening in picture detail. See antialiasing.
The stair-stepped (jagged) appearance in printed diagonal lines.
The stair-step effect caused by square pixels on a computer screen.
An aliased image is frequently said to have "jaggies." Aliasing is a technique used for bitmap file display to make diagonal edges look smoother by setting pixels close to the edge to intermediary colors according to where the edge crosses them.
In graphic design, aliasing occurs when a computer monitor, printer, or graphics file does not have a high enough resolution to represent a graphic image or text. The resulting image is blurry, and often said to be pixellated.
An occurrence of sampled data interference. This can occur in CCD image projection of high spatial frequencies and is also known as Moiré patterning. It can be minimized by a technique known as optical low pass filtering.
the presence of alias frequencies in acquired data
The visual stair-stepping of edges (jagged edges) that occurs in an image when the resolution is too low. Can be caused by improper image sampling or improper image processing.
Pixel-shaped curves on the diagonal edges of objects. This can sometimes occur since all graphics consist of individual pixels. Anti-aliasing reduces this unwelcome effect by recalculating the contrast values of the neighbouring pixels and matching them up with each other.
This term is commonly applied to spatial aliasing, which manifests as visible pixelation - a blocky or jagged effect - especially with near horizontal or near vertical lines of high contrast.
A phenomenon which can occur whenever a signal is not sampled at greater than twice the maximum bandwidth of the signal. Causes high frequency signals to appear at low frequencies. Aliasing is minimized by filtering the signal to a bandwidth less than 1/2 the sample rate. When the signal starts at 0 Hz (baseband signals), bandwidth can be exchanged to maximum frequency in the definition above.
Where the sampling rate is less than twice the input signal's highest frequency content.
Defects or distortion in a television picture or audio. Defects are typically seen as jagged edges on diagonal lines and twinkling or brightening. In digital video, aliasing is caused by insufficient sampling or poor filtering of the digital video.
The noticeable repeated patterns, lines, or textures in any photographed or scanned subject that conflict with the pattern of an electronic sensor's pixel arrangement. For example diagonal lines represented by square pixels will produce jagged lines.
The jagged and stair-stepped appearance of curved and diagonal lines of a graphic image. Filling in adjacent pixels can soften the jagged appearance with intermediate colors between the object and the background. This softening of the edges is called anti-aliasing. Software like PhotoShop can apply anti-aliasing for you automatically. It is often the default setting.
Undesirable visual effects (sometimes called artefacts) in imagery largely caused by improper sampling techniques. In raster imagery generated from vector data, a common aliasing effect is a jagged line along object boundaries.
In spectral analysis, error which is due to undersampling. One may wish to sample a signal that is known to be band-limited, but whose bandwidth is not known a priori. The Fourier transform of Shannon's series is periodic; aliasing is of the form of an overlapping, or superposition of these "replicated" spectra. See also Nyquist sampling rate and aliased response. 2. In computer graphics, the jagged artifact in a line or curve that results from drawing on a raster grid. 3.
An undesirable jagged edge on many 3D renderings on bitmapped displays. Creates jaggies along the sides of objects and flickering of objects smaller than a pixel. (see Anti- Aliasing )
Aliasing is the visual stair stepping of edges (jagged edges) that occurs in an image when the resolution is too low. Anti-Aliasing is the smoothing and removing of aliasing effects by electronic filtering and other techniques such as blending of hard edges.
Undesirable data anomalies present in image data. See also spatial and temporal aliasing.
In a sampled data system, the analog input must be sampled at a rate of FS2FA in order to avoid loss of data (Nyquist Theorem). Adhering to the Nyquist Theorem prevents in-band "alias" signals, which are beat frequencies between the analog signal and the sampling clock that inherently occur at FS± FA. As the Nyquist limit is exceeded, the aliased signals move within the band of the analog input (DC - FS/2) and create distortion. Likewise, high-frequency noise can also be aliased into the input signal range, which mandates low-pass filtering, or anti-alias filtering, on the input of a sampled system. See also Aliased Imaging.
Jagged edges in text and also along the outer boundaries of diagonal or curved objects. Anti-aliasing refers to software compensation that minimize this effect.
Undesired frequencies that are produced when harmonic components within the audio signal being sampled by a digital recording device or generated within a digital sound source lie above the Nyquist frequency. Aliasing differs from some other types of noise in that its pitch changes radically when the pitch of the intended sound changes. See Nyquist frequency.
Anti-aliasing removes the blocky or jagged effect on text and graphics.
A distortion (artifact) in the reproduction of digital audio or video that results when the signal frequency is more than twice the sampling frequency. The resolution is insufficient to distinguish between alternate reconstructions of the waveform, thus admitting additional noise that was not present in the original signal.
An artifact produced by distorting or not using the high frequency components of an image, signal, data stream, etc. due to some limitation such as undersampling or inadequate detection bandwidth. The result is unwanted appearance of low frequency components (aliases) which must be filtered out and replaced with the missing high frequency components. The process of removal/replacement of frequencies is called "anti-aliasing".
In computer graphics, the process by which smooth curves and other lines become jagged because the resolution of the graphics device or file is not high enough to represent a smooth curve. Smoothing and antialiasing techniques can reduce the effect of aliasing.
Incorrect sampled data obtained by either not sampling fast enough or not bandlimiting the signal prior to sampling. Can result in artifacts inserted into the image.
In sampling theory, an input signal (fIN) must be sampled with at least twice its frequency (Nyquist criteria, fSAMPLE fIN). If the input tone exceeds the Nyquist limit, the signal is folded back (aliasing) or replicated at other frequencies in the frequency spectrum above and below Nyquist ( see also Nyquist Frequency). Caused by unwanted signal components above Nyquist, aliasing can be avoided by introducing front-end anti-aliasing filters to attenuate those signals.
Visibly jagged steps along angled lines or object edges, due to sharp tonal contrasts between pixels.
n. In computer graphics, the jagged appearance of curves or diagonal lines on a display screen, which is caused by low screen resolution.
In sampling theory, input-signal frequencies that exceed the Nyquist frequency are "aliased." That is, they are "folded back" or replicated at other positions in the spectrum above and below the Nyquist frequency. To prevent aliasing, you must adequately filter all undesired signals so the ADC does not digitize them. Aliasing can be used to advantage when undersampling. See also application note Filter Basics: Anti-Aliasing
Defects in the picture caused by too low a sampling frequency or poor filtering. Usually scene as "jaggies" or stair steps in diagonal lines.
An unwanted stair-stepped appearance on uncorrected curves and angled lines in graphics or text. Aliasing can be corrected in many applications applying anti-aliasing.
The jagged edge in a bitmap graphic.
One of several types of digital video artifact appearing as jagged edges. Aliasing results when an image is sampled that contains frequency components above the Nyquist limit for the sampling rate. See also Nyquist limit.
If the sample rate of a function (fs) is less than two times the highest frequency value of the function, the frequency is ambiguously presented. The frequencies above (fs/2) will be folded back into the lower frequencies producing erroneous data.
This term is borrowed from signal processing, and describes when a function is undersampled, yielding unwanted results. For example, drawing a diagonal line on a low-resolution raster display, yields an undesirable "staircase" look.
Condition when graphics, either constructed with lines (vectored) or dots (bitmapped), show jagged edges under magnification.
Effect of visual stair-stepping of edges of diagonal lines, edges of circles, etc because pixels that make up a digital picture are square.
false frequencies'' that are created when sampling frequencies greater than one-half the sampling rate.
In a sampled data system, the analog input must be sampled at a rate of at least twice the bandwidth of the signal in order to avoid loss of data (Nyquist Theorem). Adhering to the Nyquist Theorem prevents in-band "alias" signals, which are beat frequencies between the analog signal and the sampling clock that inherently occur.
In bitmapped graphics, the jagged boundary along the edges of different coloured shapes within an image.
A type of distortion that occurs when digitally recording high frequencies with a low sample rate. A visual analogy can be found in video, when a car's wheels appear to slowly spin backwards while the car is quickly moving forward. Similarly when you try to record a frequency greater than one half of the sampling rate (Nyquist Frequency), instead of hearing a high pitch you may hear a low frequency rumble. An anti-aliasing filter can be used to remove high-frequencies before recording. However, once a sound has been recorded, aliasing distortion is impossible to remove without also removing other frequencies from the sound.
Aliasing refers to visual effects showing jagged edges (jaggies) in text, icons and graphic objects. Anti-aliasing refers to software compensation that minimizes this effect.
When smooth lines and curves in a digital image become distorted due to low resolution.
The result of sampling a signal at less than twice its natural frequency. Aliasing causes data to be lost in the conversion that occurs when resampling an existing signal at more than twice its natural frequency.
False signals in the frequency domain caused by a measuring rate for digitising that is too slow.
A pattern of image sampling error in digital systems. Aliasing forces spatial frequency components higher than a critical value (the Nyquist frequency) to be displayed at progressively lower frequencies. Aliasing introduces an undesirable moiré pattern when the spatial frequency of the signal exceeds the sampling rate in a digitizer.
A distortion caused by improper waveform reconstruction during the reproduction of an audio or video signal. Aliasing creates “noise” that is not in the original signal.
Jagged edges along the outer edge of objects or text. Anti-aliasing refers to software adjustments that correct this effect. This effect is created by inadequate sampling techniques in computer-produced images. Backlit A remote control, projector control panel, or other object illuminated from behind. This can be helpful when working in darkened rooms.
Visual stair-stepping of edges that occurs in an image when the resolution is too low for the size of the output. Anti-aliasing is the removal or softening of the rough edges (or jaggies) by averaging or blending of surrounding colors. See also jaggies.
is an effect caused by sampling an image (or signal) at too low a rate. It makes rapid change (high texture) areas of an image appear as a slow change in the sample image. Once aliasing occurs, there is no way to accurately reproduce the original image from the sampled image.
1. The introduction of error in the Fourier analysis of a discrete sampling from continuous data, by which frequencies too high to be analyzed with the discrete sampling interval erroneously contribute to the amplitude of the lower frequencies. Aliasing can be avoided by filtering out the high frequencies (using slower-response instruments or analog electronic circuits) before sampling or digitizing. See also Nyquist frequency. 2. In radar, sodar, and lidar, the folding of target returns from outside the normal unambiguous range interval ( range folding) into the normal range interval, or the folding of radial velocity measurements outside the unambiguous velocity interval ( velocity folding) into the normal velocity interval.
Aliasing is a graphic design term and it occurs when a computer printer, monitor, or graphic file does not have enough resolution to properly display a graphic.
a misrepresentation of the measurement caused by sampling more slowly than the signal being measured. For example, if your signal had a 2500 Hz component and you sampled at 1000 samples per second, aliasing would occur. The waveform that you observe in your sampled data may have a "ghost" wave at, for example, 100 Hz. This wave actually never existed and is a result of aliasing. Aliasing cannot be easily removed once it occurs and often, users are unaware that it has occurred, resulting in incorrect conclusions being drawn. To avoid aliasing, the sample period must be increased or a hardware filter be implemented before sampling occurs to remove high frequencies.
when raster images show jagged edges when magnified. Anti-Aliasing is when the jagged edges are masked with surrounding lighter pixels to create a smooth edge.
An image sampling error in digital systems manifesting itself as spatial frequency components beyond the sampling limit (Nyquist frequency) that are displayed at progressively lower frequencies. Aliasing can produce moiré pattern artifact in an image when the spatial frequency of the signal exceeds the sampling rate of the digitizer.
Aliasing is a "staircase" or jagged effect that occurs when display resolution is too coarse to minimize the broken appearance of certain electronic design elements. Aliasing is more visually pronounced in diagonal lines, curves, and circles. To avoid aliasing, you should save your files with "Anti-Alias" to keep the text smooth when printed.
Undesirable picture inaccuracies ("artifacts") caused by excessive deatail in the videso signal. Most common are "jaggies" or "stair-stepping" on angled lines, or strobing effects on sharp thin horizontal lines.
The effect produced when a complex image is put onto a display with a limited resolution. This effect is a product of downsampling. Examples include jagged looking lines in lower resolutions. Temporal aliasing is the effect where motion appears stuttered due to a low frame rate (for the speed).
A set of problematic effects resulting from the usual method of displaying *scalable images on low-resolution screens. When converting these images to *bitmaps for display, samples are taken from the theoretical mathematical image, usually at the pixel centres. The influence of what is happening at these more or less arbitrary points is thereby greatly exaggerated, causing jagged edges, "pimples" and other undesirable effects. (We should really be considering what is happening over the complete area covered by each pixel.) The approach to the problem that takes the generic term, *anti-aliasing, normally denotes careful shading of border pixels. Another approach (distinct but complementary) is *hinting, a set of techniques that can in principle regularize features of any graphic, but in practice is confined to font technology.
