The visual appearance of objects is given by the way in which they reflect and transmit
light. The colorof objects is determined by the parts of the spectrumof (incident white) light that are reflected or transmitted without being absorbed. Additional appearance attributes are based on the directional distribution of reflected ( BDRF) or transmitted light (BTDF) described by attributes like glossy, shiny versus dull, matte, clear, distinct, etc..
Appearance of reflective objects
The appearance of reflecting objects is determined by the way the surface reflects incident
light. The reflective properties of the surface can be characterized by a closer look at the (micro)- topographyof that surface.
Structures on the surface and the texture of the surface are determined by typical dimensions between some 10 mm and 0,1 mm (the detection limit of the human eye is at ~0,07 mm). Smaller structures and features of the surface cannot be directly detected by the unaided eye, but their effect becomes apparent in objects or images reflected in the surface. Structures at and below 0,1 mm reduce the "distinctness of image" (DOI), structures in the range of 0,01 mm induce "haze" and even smaller structures affect the "gloss" of the surface.
scattering: process by which the spatial distribution of a beam of radiation is changed in many directions when it is deviated by a surface or by a medium, without change of frequency of its monochromatic components. [CIE No17.4-1987: International lighting vocabulary, 4th ed. (Joint publication IEC/CIE)]
Appearance of transmissive objects
Reflective objects [ASTM Standards on Color & Appearance Measurement]
* "Reflectance Factor, R"
* "Gloss Reflectance Factor, Rs"
* "Gloss" (at least six types of "gloss" may be observed depending upon the character of the surface and the spatial (directional) distribution of the reflected light.)
* "Specular Gloss"
* "Distinctness-of-Image Gloss"
* "Reflection Haze, H"
Transmissive objects [ASTM Standards on Color & Appearance Measurement]
* "Transmittance, T"
* CIE No38-1977: Radiometric and photometric characteristics of materials and their measurement
* CIE No 44-1979: Absolute methods for reflection measurements
* F. E. Nicodemus, et al., Geometric Considerations and Nomenclature for Reflectance, U.S. Dept. of Commerce, NBS Monograph 160 (1977)
* John C. Stover, Optical Scattering, Measurement and Analysis, SPIE Press, 1995
Instrumentation for measurement and evaluation of appearance characteristics is available from:
* [http://www.bykgardner.com/ BYK-Gardner]
* [http://www.hunterlab.com/ HunterLab]
* [http://www.display-messtechnik.de/ DM&S]
Wikimedia Foundation. 2010.
Look at other dictionaries:
Appearance — may refer to:* In physiognomy, Human physical appearance. * The visual appearance of objects is given by the way in which they reflect and transmit light. The color of objects is determined by the parts of the spectrum of light that are reflected … Wikipedia
Visual memory — Close up of the human eye, where vision begins. Visual memory describes the relationship between perceptual processing and the encoding, storage and retrieval of the resulting neural representations. Visual memory occurs over a broad time range… … Wikipedia
Visual kei — Stylistic origins Various (mainly rock, metal, punk and pop music) Cultural origins Japan Typical instruments Guitar, bass, drums, keyboards Mainstre … Wikipedia
Visual literacy — (or, as it is colloquially known, visuacy [Christopher Allen, in The Australian on 16 August, described this word as a horrible neologism .] ) is the ability to interpret, negotiate, and make meaning from information presented in the form of an… … Wikipedia
Visual networking — refers to an emerging class of user applications that combine digital video and social networking capabilities. It is based upon the premise that visual literacy, the ability to interpret, negotiate and make meaning from information presented in… … Wikipedia
Visual flight — is the control and navigation of an aircraft by using the view from the aircraft as the primary reference point. A pilot observes the outside world and uses the flight controls to take the aircraft safely to the place they want to go. The… … Wikipedia
Visual refresh — refers to practice of providing a new skin or theme for a computer program whenever a new version is released. Thus it prevents the appearance of the program becoming stale to long term users, and enhances the apparent differentiation between the … Wikipedia
appearance — I (New American Roget s College Thesaurus) Outward look Nouns 1. (what is seen) sight, show, scene, view; outlook, prospect, vista, angle, perspective, bird s eye view; scenery, landscape, picture, tableau; display, setting, mise en scène. See… … English dictionary for students
Visual acuity — 20/15 and 20/15 vision redirect here. For other uses, see 2020 (disambiguation). Typical Snellen chart used for visual acuity testing. Visual acuity (VA) is acuteness or clearness of vision, which is dependent on the sharpness of the retinal… … Wikipedia
Visual Basic — This article is about the Visual Basic language shipping with Microsoft Visual Studio 6.0 or earlier. For the Visual Basic language shipping with Microsoft Visual Studio .NET or later, see Visual Basic .NET. Visual Basic Paradigm(s) Object based… … Wikipedia