SAE J 264-1998 Vision Glossary.pdf

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1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro

2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.Copyright 2004 SAE InternationalAll rights reserved. No part of this publication may be

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4、776-0790Email: custsvcsae.orgSAE WEB ADDRESS: http:/www.sae.orgSURFACEVEHICLEINFORMATIONREPORTJ264REAF.JUN2004Issued 1971-09Reaffirmed 2004-06Superseding J264 SEP1998Vision Glossary1. ScopeThe function of uniform terminology is to promote understandable and exact communication in thearea of vision.

5、A great deal of effort has been expended to make these definitions suit this purpose. It isrecognized that this terminology, like other dictionaries, must be revised periodically to reflect current usageand changing needs. The Driver Vision Subcommittee of the Human Factors Engineering Committee,the

6、refore, solicits suggestions for improvements and additions to be considered in future revisions.2. References2.1 Related PublicationsThe following publications are provided for information purposes only and are not arequired part of this document.Boff, K. R., Kaufman, L., and Thomas, J. P. (Eds.),

7、Handbook of Perception and Human Performance:Volume 1 Sensory Processes and Perception, New York: John Wiley and Sons, 1986Boff, K. R., Lincoln, J. E. (Eds.), Engineering Data Compendium, Human Perception and Performance:Volume 1, Harry G. Armstrong Aerospace Medical Research Laboratory, Wright-Patt

8、erson Air ForceBase, Ohio, 1988Cornsweet, T. N., Visual Perception, New York: Academic Press, 1970Schiff, W., Perception: An Applied Approach, Boston: Houghton Mifflin Company, 1980Sekular, R., and Blake, R., Perception (3rd edition). New York: McGraw-Hill, Inc., 1994Wyszecki, G., and Stiles, W. S.,

9、 Color Science: Concepts and Methods, Quantitative Data and Formulae.New York: John Wiley and Sons, 19823. Definitions3.1 Field of View3.1.1 AMBINOCULAR FIELD OF VIEWThe total field of view that can be seen by either eye. It is the combination ofall of the right and all of the left monocular fields

10、of view.NOTEThe ambinocular field of view is larger than the binocular field of view.3.1.2 BINOCULAR FIELD OF VIEWThe field of view that can be seen simultaneously by both eyes (i.e., only theoverlapping areas of the right and left monocular fields of view).3.1.3 CENTRAL FIELD OF VIEW(See Foveal Fie

11、ld of View.)SAE J264 Reaffirmed JUN2004-2-3.1.4 DIRECT FIELD OF VIEWThe field of view which can be viewed directly, without any mirrors or other imagingdevices (e.g., periscopes or video monitors).3.1.5 FIELD OF VIEW (VISUAL FIELD)The extent of visual space over which vision is possible with the eye

12、s in afixed position (i.e., while looking straight ahead, it is the entire region of space visible). The size of the visualfield is influenced by such individual factors as age, alcohol, anxiety, attentiveness, drugs, fatigue, gender,and general health.3.1.6 FOVEAL FIELD OF VIEW (CENTRAL FIELD OF VI

13、EW)The small, 1 to 2 degree region in the center of the visualfield where visual acuity is greatest.3.1.7 INDIRECT FIELD OF VIEWThe field of view provided by imaging devices (e.g., mirrors, periscopes, or videomonitors).3.1.8 MONOCULAR FIELD OF VIEWThe field of view that can be seen by one eye.3.1.9

14、 PERIPHERAL FIELD OF VIEWThe outer, non-foveal field of view. For practical purposes, anything beyond thesmall (1 to 2 degree) central area of vision can be considered part of the peripheral field of view. This area ischaracterized by (a) poor acuity, (b) poor color discrimination, and (c) optimal s

15、ensitivity to low levels of light.3.1.10 PRIMARY LINE OF SIGHTThe line connecting the point of observation and the fixation point. (The point ofobservation is the midpoint of a line connecting the centers of rotation of the two eyes.)3.1.11 VISUAL FIELD(See Field of View.)3.2 Psychophysics3.2.1 ABSO

16、LUTE THRESHOLDThe minimum value required for the presence of a stimulus or stimulus attribute tobe detected. For example, the minimum intensity required for a light to be detected, or the minimum amountof contrast required for a pattern to be detected. The more perceptible a stimulus isor the more s

17、ensitivethe observerthe lower the absolute threshold will be. See threshold.3.2.2 DIFFERENCE THRESHOLDThe least amount by which two stimuli must differ along a given dimension (e.g.,intensity, color, length, weight, etc.) to be perceived as different. The more perceptible a difference isor themore s

18、ensitive the observerthe lower the difference threshold will be. See threshold.3.2.3 JUST-NOTICEABLE DIFFERENCE (JND)(See difference threshold.)3.2.4 PSYCHOPHYSICSThe study of the quantitative relationship between physical aspects of a stimulus and theperception of that stimulus.3.2.5 SENSITIVITYAs

19、a psychophysical expression, it is the reciprocal of the measured threshold. For example,contrast sensitivity is the reciprocal of contrast threshold; a spectral sensitivity curve plots the reciprocals ofthe thresholds obtained for each of the wavelengths.3.2.6 STEVENS POWER LAW (POWER FUNCTION)The

20、mathematical relationship between physical magnitude andperceived magnitude. S. S. Steven found that the perceived magnitude was a function of the stimulusmagnitude raised to a power (S = klb, where S = the perceived magnitude, k is a constant, and l is the actualphysical magnitude). The exponents v

21、alue, b, is specific to modality (vision, audition, taste, etc.) andstimulus attribute of interest (brightness of a light versus redness of a light, for example).SAE J264 Reaffirmed JUN2004-3-3.2.7 THRESHOLDThe smallest value of a stimulus which results in a change in perceptual states (e.g., seeing

22、versus not seeing). Thresholds are mathematically defined, usually as the point at which performance is50%. (For example, the intensity of light which can just be seen 50% of the time.) See also absolutethreshold and difference threshold.3.2.8 WEBERS LAWA psychophysical law which states that the rel

23、ationship between the initial stimulus intensityand the change in intensity required to perceive a difference (difference threshold) is a constant. Weberslaw is usually expressed as the equation l / l = k, where l is the initial intensity, l is the smallest detectablechange in intensity, and k is th

24、e constant.3.3 Retina3.3.1 BLIND SPOT (OPTIC DISC)The area of the retina where the fibers of the optic nerve leave the eye. This areacontains no photoreceptors and is therefore insensitive to light.3.3.2 CONESThe type of photoreceptor responsible for color vision and resolution of fine detail (acuit

25、y). Conesonly function at high light levels (referred to as photopic vision). Most people have three types of cones, eachcontaining a different photopigment. Abnormalities in one or more of the cone types will result in a deficiencyof color vision. The type of vision provided by cones is analogous t

26、o a picture taken with slow, highresolution, color film. Cones are the only type of photoreceptor found in the fovea. Although there are somecones in the peripheral areas, their number falls off rapidly as you move away from the center of the retina.3.3.3 FOVEAThe small, central area of the retina (

27、1 to 2 degrees visual angle), with the highest density ofphotoreceptors. When a viewer focuses on an object, it is imaged on the fovea. Foveal vision is chromaticand has the greatest visual acuity.3.3.4 OPTIC NERVEThe nerve bundle which transmits retinal sensations from the eye to the brain.3.3.5 PH

28、OTOPIGMENTA light sensitive molecule contained within the photoreceptors of the eye. There are fourdifferent types of photopigments (one found in rods, and three different types for cones). Each photopigmentabsorbs light of various wavelengths to a different degree.3.3.6 PHOTORECEPTORSSpecialized ne

29、rve cells (rods and cones) found in the retina of the eye that contain light-sensitive materials (called photopigments).3.3.7 RETINAAn outgrowth of the brain forming a thin lining at the back of the eyeball and containing the light-sensitive rods and cones which are the peripheral end organs of the

30、optic nerve.3.3.8 RODSThe most light-sensitive type of photoreceptor. Rods form an achromatic (color blind) part of thevisual system, which is functional even at low light levels (scotopic vision). However, acuity is very poor. Thetype of vision created by rods is analogous to a picture taken with f

31、ast but coarsely grained photographic film.Rods are located throughout the retina, except in the fovea and the blind spot, and are primarily responsiblefor peripheral vision.3.4 Sensitivity to Light3.4.1 GLAREThe light or reflection from a relatively bright light source (compared to the luminance le

32、vels in therest of the visual field.) Depending on the relative intensity of the glare source and the physical condition ofthe observer:a. Glare can result in annoyance, discomfort, visual fatigue, reduced visual ability, and even temporary“blindness;“b. The effect of glare can be magnified by the s

33、cattering of light inside the observers eyes (this problembecomes more prevalent with increasing age).SAE J264 Reaffirmed JUN2004-4-3.4.1.1 Discomfort GlareGlare of sufficient magnitude so as to cause annoyance or discomfort.3.4.1.2 Disability GlareGlare of sufficient magnitude so as to cause a redu

34、ction in visual ability.3.4.2 LATERAL INHIBITIONLateral inhibition refers to antagonistic interactions between neighboring neural regions.In terms of vision, stimulating one area of the retina with light may cause adjacent areas to be lessresponsive. Essentially, excitation in one cell causes an inh

35、ibitory message to be sent to other neighboringcells. Lateral inhibition occurs throughout the visual pathway, and is believed to play a key role in suchdiverse phenomena as contrast effects, Mach bands, and color perception.3.4.3 MESOPICRefers to the low and intermediate levels of light (0.001 to 1

36、00 candelas/meter2), that fall betweenphotopic and scotopic levels, or the type of vision available under these lighting conditions. Both rods andcones contribute to mesopic vision.3.4.4 PHOTOPICRefers to daylight levels of illumination (100 candelas/meter2), or the type of vision which isavailable

37、when the eyes are adapted to these light levels. Photopic vision is mediated by the cones. Peakspectral sensitivity for photopic vision occurs at approximately 555 nm. Overall spectral sensitivity ofphotopic vision is lower than that observed for scotopic vision. Photopic vision becomes fully dark a

38、dapted(i.e., reaches maximum sensitivity) after 5 to 6 min in the dark.3.4.5 SCOTOPICRefers to exceptionally low light levels (0.001 candelas/meter2), or the type of vision availablewhen the eyes are adapted to these low levels of illumination. Scotopic vision is mediated by the rods, and ischaracte

39、rized by reduced contrast sensitivity, poor acuity, and achromatic vision. Peak spectral sensitivity forscotopic vision occurs at approximately 505 nm. Overall spectral sensitivity of scotopic vision is higher thanthat observed for photopic vision. Dark adaptation of the scotopic system takes at lea

40、st 20 min, and maycontinue for 30 to 40 min.3.4.6 SPECTRAL SENSITIVITYThe sensitivity of the visual system to various wavelengths of light. Spectralsensitivity curves plot sensitivity (1/absolute threshold) as a function of wavelength. The spectral sensitivityfunction is different depending on which

41、 aspect of the visual system is tested (for example, photopic versusscotopic).3.5 Constancy and Contrast Effects3.5.1 ADAPTATIONA change in sensitivity as a result of continued or repeated exposure to stimuli of similar natureor magnitude. Adaptation may result in increased sensitivity (as is the ca

42、se with dark adaptation), or indecreased sensitivity (which can result in aftereffects, such as successive color contrast).3.5.2 AFTEREFFECTThe effect of a past stimulus on the present perceptual experience. Aftereffects are broughtabout by prolonged or repeated exposure to a particular stimulus or

43、stimulus quality (such as color orconstant motion in one direction). This adaptation results in reduced sensitivity to that particular quality,giving rise to illusory perceptions which are in the opposite or complimentary direction. For example, afterviewing a bright green slide for several minutes,

44、 you may see a reddish patch on an otherwise white wall;viewing something that has a constant downward motion (such as a waterfall) may cause stationary objectsto appear to move upwards.3.5.3 AFTERIMAGEA visual sensation which persists for a short time after exposure to some intense stimulus.Afterim

45、ages may be positive or negative, either reproducing or being complementary to the precedingexperience.3.5.4 CONSTANCY EFFECTSThe general tendency for perceptions to remain constant under a variety of condi-tions. In short, perceptions remain constant although the actual physical stimulation is diff

46、erent (compare tocontrast effects).SAE J264 Reaffirmed JUN2004-5-3.5.5 CONTRAST EFFECTSPerceptual effects that result from the interaction of two or more areas of stimulation sothat the presence of one affects the appearance of the other. For example, a particular gray patch mayappear to change colo

47、r, or to be lighter or darker, depending on its surrounding area. Contrast effects arevarying perceptions to the same physical stimulus (compare to constancy effects). See color contrast andlightness contrast.3.5.6 LIGHTNESS CONSTANCYThe tendency for the perceived lightness of an object to remain co

48、nstant despitevariations in the level of illumination. For example, when viewing an object indoors there will be much lesslight reflected back to the eye than when the same object is viewed in natural sunlight. However, thebrightness of the object will remain constant.3.5.7 LIGHTNESS CONTRASTA perce

49、ptual phenomenon where the apparent brightness or lightness of an area isinfluenced by the lightness of adjacent areas. For example, the same gray patch will appear lighter whensurrounded by a black area, but will appear darker when surrounded by white. An example of lightnesscontrast is the perception of black in a television image. The actual image cannot be any darker than thelightness of the screen when the television is turned off. It is assumed that lateral inhibition is primarilyresponsible for this effect.3.5.8 MACH BAN