Colonel Crawford Burn Site Monument drawing

Digital artifact in information science, is any undesired or unintended alteration in data introduced in a digital process by an involved technique and/or technology. Digital artifact can be of any content types including text,

audio Audio most commonly refers to sound, as it is transmitted in signal form. It may also refer to: Sound *Audio signal, an electrical representation of sound *Audio frequency, a frequency in the audio spectrum *Digital audio, representation of sound ...

video Video is an Electronics, electronic medium for the recording, copying, playback, broadcasting, and display of moving picture, moving image, visual Media (communication), media. Video was first developed for mechanical television systems, whi ...

image An image or picture is a visual representation. An image can be Two-dimensional space, two-dimensional, such as a drawing, painting, or photograph, or Three-dimensional space, three-dimensional, such as a carving or sculpture. Images may be di ...

animation Animation is a filmmaking technique whereby still images are manipulated to create moving images. In traditional animation, images are drawn or painted by hand on transparent celluloid sheets to be photographed and exhibited on film. Animati ...

or a combination.

Information science

In information science, digital artifacts result from: *Hardware malfunction: In

computer graphics Computer graphics deals with generating images and art with the aid of computers. Computer graphics is a core technology in digital photography, film, video games, digital art, cell phone and computer displays, and many specialized applications. ...

visual artifact Visual artifacts (also artefacts) are anomalies apparent during visual representation as in digital graphics and other forms of imagery, especially photography and microscopy. In digital graphics * Image quality factors, different types of v ...

s may be generated whenever a hardware component such as the processor,

memory chip Semiconductor memory is a digital electronic semiconductor device used for digital data storage, such as computer memory. It typically refers to devices in which data is stored within metal–oxide–semiconductor (MOS) memory cells on a sil ...

, cabling malfunctions, etc., corrupts data. Examples of malfunctions include physical damage, overheating, insufficient voltage and GPU

overclocking In computing, overclocking is the practice of increasing the clock rate of a computer to exceed that certified by the manufacturer. Commonly, operating voltage is also increased to maintain a component's operational stability at accelerated sp ...

. Common types of hardware artifacts are

texture Texture may refer to: Science and technology * Image texture, the spatial arrangement of color or intensities in an image * Surface texture, the smoothness, roughness, or bumpiness of the surface of an object * Texture (roads), road surface c ...

corruption and T-vertices in

3D graphics 3D computer graphics, sometimes called CGI, 3D-CGI or three-dimensional computer graphics, are graphics that use a three-dimensional representation of geometric data (often Cartesian) that is stored in the computer for the purposes of perfor ...

, and

pixelization Pixelization (in British English pixelisation) or mosaic processing is any technique used in editing images or video, whereby an image is blurred by displaying part or all of it at a markedly lower resolution. It is primarily used for censorshi ...

MPEG The Moving Picture Experts Group (MPEG) is an alliance of working groups established jointly by International Organization for Standardization, ISO and International Electrotechnical Commission, IEC that sets standards for media coding, includ ...

compressed video. *Software malfunction: Artifacts may be caused by algorithm flaws such as decoding/encoding audio or video, or a poor pseudo-random number generator that would introduce artifacts distinguishable from the desired noise into statistical models. * Compression: Controlled amounts of unwanted information may be generated as a result of the use of

lossy compression In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size ...

techniques. One example is the artifacts seen in

JPEG JPEG ( , short for Joint Photographic Experts Group and sometimes retroactively referred to as JPEG 1) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degr ...

and

compression algorithms that produce

compression artifacts A compression artifact (or artefact) is a noticeable distortion of media (including Image, images, Sound recording, audio, and video) caused by the application of lossy compression. Lossy data compression involves discarding some of the medi ...

. * Quantization: Digital imprecision generated in the process of converting analog information into digital space, is due to the limited granularity of digital numbering space. In computer graphics, quantization is seen as pixelation. *

Aliasing In signal processing and related disciplines, aliasing is a phenomenon that a reconstructed signal from samples of the original signal contains low frequency components that are not present in the original one. This is caused when, in the ori ...

: As a consequence of sampling or

sample-rate conversion Sample-rate conversion, sampling-frequency conversion or resampling is the process of changing the sampling rate or sampling frequency of a discrete signal to obtain a new discrete representation of the underlying continuous signal. Application a ...

, energy from frequencies outside of the signal

frequency band Spectral bands are regions of a given spectrum, having a specific range of wavelengths or frequencies. Most often, it refers to electromagnetic bands, regions of the electromagnetic spectrum. More generally, spectral bands may also be means in ...

of interest are folded across multiples of the

Nyquist frequency In signal processing, the Nyquist frequency (or folding frequency), named after Harry Nyquist, is a characteristic of a Sampling (signal processing), sampler, which converts a continuous function or signal into a discrete sequence. For a given S ...

. This is typically mitigated by using an anti-aliasing filter. * Filtering: The process of filtering a signal, such as using an anti-aliasing filter, causes undesired alterations to the signal due to imperfections in the

frequency response In signal processing and electronics, the frequency response of a system is the quantitative measure of the magnitude and Phase (waves), phase of the output as a function of input frequency. The frequency response is widely used in the design and ...

magnitude and phase, and due to the

time domain In mathematics and signal processing, the time domain is a representation of how a signal, function, or data set varies with time. It is used for the analysis of mathematical functions, physical signals or time series of economic or environmental ...

impulse response In signal processing and control theory, the impulse response, or impulse response function (IRF), of a dynamic system is its output when presented with a brief input signal, called an impulse (). More generally, an impulse response is the reac ...

. * Rolling shutter, the line scanning of an object that is moving too fast for the image sensor to capture a unitary image. * Error diffusion: poorly-weighted kernel coefficients result in undesirable visual artifacts.

References

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External links

DPReview: Glossary: Artifacts
Anthropology Archaeology Information science Error Computer graphic artifacts Digital photography