Visual comparison

A visual comparison is to compare two or more things by eye. This might be done by placing them side by side; by overlaying them; by alternating an image or by presenting each image to a separate eye.

Such comparisons are the first stage in a child's development of an understanding of geometry and measurement, before they move to an understanding of measuring devices such as a ruler. [cite book|title=The Child's Conception of Geometry|author=Jean Piaget, Bärbel Inhelder, Alina Szeminska|pages=33|url=http://books.google.com/books?id=A-yQR6DxTkUC|isbn=0415209994|year=1999|publisher=Routledge]

People with good control of the parallax of their eyeballs (e.g. those who can easily view random-dot stereograms), can hold up images and go cross-eyed to superimpose them. This invokes the same visual processes responsible for depth perception and differences stand out almost immediately. This technique is good for finding edits in graphical images, or for comparing an image with a compressed version to spot artifacts.

Visual comparison with a standard chart or reference is often used as a means of measuring complex phenomena such as the weather, sea states or the roughness of a river. [cite book|title=Roughness Characteristics of New Zealand Rivers|author=D. Murray Hicks, Peter D. Mason|url=http://books.google.co.uk/books?id=Oez427pUSB0C|isbn=4770260873|year=1991] A colour chart is used for this purpose in many contexts such as chemistry, cosmetics, medical testing and photography.

Comparison by eye may also be used as a source of amusement or intelligence testing, as in the popular puzzle of spot the difference.

In policing, the technique is used for analysis of fingerprints and identity parades.

ee also

* Beaufort scale
* Blink comparator
* Hinman Collator
* Visual inspection
* Visual search

References


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Visual inspection — is a common method of quality control, data acquisition, and data analysis. Visual Inspection, used in maintenance of facilities, mean inspection of equipment and structures using either or all of human senses such as vision, hearing, touch and… …   Wikipedia

  • Visual Basic .NET — Paradigm(s) Structured, imperative, object oriented and declarative Appeared in 2001 Designed by Micro …   Wikipedia

  • Visual Studio Tools for Office — (VSTO) is a set of development tools available in the form of a Visual Studio add in and a runtime that allows Microsoft Office 2003 and later versions of Office applications to host the .NET Framework Common Language Runtime (CLR) to expose… …   Wikipedia

  • Visual Studio 2005 Express — Visual Studio Express Тип Интегрированная среда разработки Разработчик ОС Windows Версия 2008 Лицензия Сайт www.microsoft.com Microsoft Visua …   Википедия

  • Visual Studio Express — Тип Интегрированная среда разработки Разработчик ОС Windows Версия 2008 Лицензия Сайт www.microsoft.com Microsoft Visua …   Википедия

  • Visual phototransduction — is a process by which light is converted into electrical signals in the rod cells, cone cells and photosensitive ganglion cells of the retina of the eye.The visual cycle is the biological conversion of a photon into an electrical signal in the… …   Wikipedia

  • Visual arts by indigenous peoples of the Americas — encompasses the visual artistic traditions of the indigenous peoples of the Americas from ancient times to the present. These include works from South America, Mesoamerica, North America including Greenland, as well as Siberian Yup ik peoples who …   Wikipedia

  • visual acuity — n. the ability of the eye to discriminate detail, usually tested by comparison with the power of the normal eye to distinguish certain letters on a standard chart at a given distance, generally 20 feet …   English World dictionary

  • Comparison of C Sharp and Visual Basic .NET — The correct title of this article is Comparison of C# and Visual Basic .NET. The substitution or omission of the # sign is because of technical restrictions. Programming language comparisons General comparison Basic syntax Basic instructions …   Wikipedia

  • Comparison of programming languages (basic instructions) — Programming language comparisons General comparison Basic syntax Basic instructions Arrays Associative arrays String operations …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.