DOCSLIB.ORG

Which Color Differencing Equation Should Be Used?

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Which Color Differencing Equation Should Be Used? International Circular of Graphic Education and Research, No. 6, 2013 science & technology Which color differencing equation should be used? Martin Habekost Keywords: Colour differencing, Color, CIE, Colorimetry, Differencing, Delta E Color differencing equations have been in used for quite some time. In 1976 the CIE released the ΔEab-formula, weighting02_Habekost_Formulas function (kLSL), a chroma weighting function All these equations try to overcome the drawbacks of which is still widely used in industry and in research. This formula has its drawback and a number of other (kCSC), a hue weighting function (kHSH), an interactive the L*a*b-color space by introducing correction terms to color differencing formulas have been issued that try to accommodate how the human observer perceives color term between chroma and hue differences for improv- the non-uniform L*a*b*-color space. differencing in different areas of the color space. Trained and untrained observers in regards to judging color ing the performance for blue colors and a factor (RT) for differences were asked to rank color differences of test colors. In both cases the ΔE2000 formula corresponded * *2 *2 *2 rescalingEab the LCIELab aa*-axis bfor improving performance 2. Application of various ΔE-equations best with the way both groups of observers perceived these color differences. When industry experts were asked for grey colours. to rank perceived color differences without having a standard to compare to the CMC1:1 formula corresponds The CIE was not the only body that released a color In this paper three individual studies have been well with their observations. Although the ΔE2000 is mathematically more complicated than the ΔEab formula differencing equation2 to address2 the shortcomings2 of combined to achieve a better understanding of the the TC130 is mentioning guideline values (not official standard values) for evaluating process colors in the ISO L* C* h* 12646-2 procedure in its latest draft version. This is an indication that the ΔE2000 formula will soon become the theE ΔEab-formula.* In 1984 the CMC (Color Measure- correlation between the ΔE-values that the different 94 standard color differencing equation and replace the ΔEab formula. ment Committee kL SL of the SocietykC SC of Dyes kH SandH Colorists of color differencing equations produce for the differences 02_Habekost_Formulas Great Britain) (Clarke, 1984) also developed an equation between two colors and how the human perception of that is based on the L*C*h*-notation of colors. color differences correlates with these ΔE-values. 1. Introduction This equation takes2 the various2 color sensitivities2 of the human* visualL system intoC consideration H and a ΔE C 2.1 ObservationsH of color differences by untrained 2 2 2 E R * * * * 00 T Color differencing equations have been used for quite forE calculatingab L color adifferences.b The ΔE94-formula of 1.0 under k CMCLSL gives thekC S sameC visual kH SdifferenceH in kallC SC observers kH SH some time. In 1976 the CIE published the first inter- looks as follows: regions of the color-wheel. The ΔEab equation has been widely used in industry nationally endorsed color differencing equation. This The formula looks as follows: and research, but are the other equations being used or 2 formula called ΔEab or ΔE76 deemed a difference or * 2 * * 2 is one more dominantly used and how do the measured * L C h 2 2 2 ΔE of 1.0 to be the smallest difference perceivable by E (1.2) * * * color difference correspond with how observers perceive 94 * L C h the human eye. This formula has been used in many ISO kL SL kC SC kH SH E (1.4) the color differences. CMC procedures such as 12647-2 for process control in the lSL cSC SH The author of this paper conducted a study (Habe- production of halftone color separations, proof and pro- This equation has two sets of coefficients. The k- kost, 2007) with untrained observers. The observers duction prints. This color differencing equation made it coefficients are also2 known as 2parametric factors2 and The SL, SC and SH are the main weighting factors for had to look at 34 different colors and their variations. possible to better communicate color differences under refer* to effects LinfluencingC color-differenceH judgment. C H lightness, chroma and hue. The two factors l and c are The variations had a ΔEab of 2, 5, 5.5 and 7 to the E00 RT standard illuminants and observers. The color notation The S-coefficients kLSL account kC SforC CIELab’s kH lackSH of visual kC SC kH SH constant and are defined by the user and weight the tested color. The color patches were 2x2 cm in size. The used for this equation was the L*a*b*-color space. uniformity (Billmeyer, 2000). importance of lightness and chroma relative to the hue distribution of the tested colors in an a*,b*-plot can be It was soon discovered that this equation had its Although this formula matched closer to the color of the measured color. seen in Figure 1. shortcomings. These shortcomings were, that it was not 02_Habekost_Formulasdifference perception of the human eye it lacked some 2 2 2 taken into consideration that the human eye is more accuracy in the blue-violet* region* of the *color space, L C h sensitive to small colour differences in some regions of which * lead to the release of the ΔE2000 formula in ECMC a*b*- plot * *2 lS *2 *2 cS S the color wheel and less sensitive in others. This means 2000.Eab ThisL formula aL containsb Ca so-called H rotational term that a ΔE of 1.0 could be a small visible difference in for the blue-violet region to address the shortcomings of 70 one area of the visible spectrum (i.e. dark blue colors) the ΔE94 formula. Since this equation has a deficiency 60 2 * 2 * * 2 50 and a large visible difference in another area (i.e. light in the* blue-violet L region C a correctional h or rotational fac- E 40 pastel type colors). tor 94 was added. This corrected formula is known as the kL SL kC SC kH SH The introduction of the L*a*b*-color notation by the ΔE2000 equation (CIE, 2001): 30 20 CIE was done to bring order to the various color nota- 10 2 2 2 tions02_Habekost_Formulas and color differencing equations that were used * L C H C H 0 E R (1.3) b* (CIE, 1986). The ΔEab equations looks as follows: 00 k S k S k S T k S k S -80 -70 -60 -50 -40 -30 -20 -10-10 0 10 20 30 40 50 60 70 80 L L C C H H C C H H -20 -30 2 2 2 * * * * -40 Eab L a b (1.1) It can be seen from this equation that the LCh has 2 2 2 * * * -50 been* transformed L into C L’, C’ andh H’. How the LCh E -60 valuesCMC are transformed into this new notation has been lSL cSC SH -70 The CIE revised the2 formula by introducing2 the2 ΔE94 explained in detail (Sharma G. W., 2005). The ΔE2000 * * * -80 formula* in 1994. L This formula C uses the L*C*h*-notationh formula has five corrections to CIELab: A lightness Figure 1: a*,b*-plot of the E a* 94 tested colors. kL SL kC SC kH SH 2 2 2 20 21 L C H C H * E00 RT kLSL kC SC kH SH kC SC kH SH 2 2 2 L* C* h* E* CMC lSL cSC SH International Circular of Graphic Education and Research, No. 6, 2013 science & technology The 02_Habekost_Graphical_Elementsobservers viewed the color patches in viewing In regards to lightness and chroma ΔE2000 and The L*a*b*-values of the test colours were entered booth with 5000K lighting. The difference between ΔECMC performed almost in a similar fashion, while into a MatLab worksheet and transformed into L*C*h*- the standard and the sample patch could be rated in regards to the hue of the tested colors the ΔECMC- values. These L*C*h*-values were modified in the way into match, slightly different, different, more different equation performed slightly better in the blue region. that color differences using ∆Eab between 2 and 7 and very different. The rankings werea* translated b* -Plot into Basically it can be said that in this study the visual resulted. Modifications were applied to each of the numbers from 5 (= match) to 1 (= very 70different) and a ranking by the untrained observers versus the color dif- three variables individually. For each standard color six ranking scheme was applied to weight60 the responses. A ference numbers resulting from the tested ΔE-equations variations were generated. This means that there were 50 typical ranking can be seen in Table 1. 40 the numbers from the ΔECMC-equation correlate better two variations in regards to Lightness, two in regards to 30 The ΔEab-values were plotted against20 the total num- than those from the ΔE2000 equation. (More details Chroma and two in regards to hue. ber and the R2-value obtained. This was10 done for the about this can be found in Habekost, 2007.) 0 b* b ΔE-values from-80 -70 all -60four -50 equations -40 -30 -20 and -10 -10all 0color 10 samples. 20 30 40 50 60 70 80 2.3 Observations by experienced observers A typical plot can be seen in Figure -202. A set of 14 test colors including neutral colors was -30 2.2. Color patches and trained observers 2 The R -values for these samples for -40the other equa- A similar experiment as mentioned in 3.1 was carried chosen for this test.
Load more

Recommended publications
  • Master Table of All Deep Space, Lunar, and Planetary Probes, 1958–2000 Official Name Spacecraft / 1958 “Pioneer” Mass[Luna] No
    Deep Space Chronicle: Master Table of All Deep Space, Lunar, and Planetary Probes, 1958–2000 Official Spacecraft / Mass Launch Date / Launch Place / Launch Vehicle / Nation / Design & Objective Outcome* Name No. Time Pad No. Organization Operation 1958 “Pioneer” Able 1 38 kg 08-17-58 / 12:18 ETR / 17A Thor-Able I / 127 U.S. AFBMD lunar orbit U [Luna] Ye-1 / 1 c. 360 kg 09-23-58 / 09:03:23 NIIP-5 / 1 Luna / B1-3 USSR OKB-1 lunar impact U Pioneer Able 2 38.3 kg 10-11-58 / 08:42:13 ETR / 17A Thor-Able I / 130 U.S. NASA / AFBMD lunar orbit U [Luna] Ye-1 / 2 c. 360 kg 10-11-58 / 23:41:58 NIIP-5 / 1 Luna / B1-4 USSR OKB-1 lunar impact U Pioneer 2 Able 3 39.6 kg 11-08-58 / 07:30 ETR / 17A Thor-Able I / 129 U.S. NASA / AFBMD lunar orbit U [Luna] Ye-1 / 3 c. 360 kg 12-04-58 / 18:18:44 NIIP-5 / 1 Luna / B1-5 USSR OKB-1 lunar impact U Pioneer 3 - 5.87 kg 12-06-58 / 05:44:52 ETR / 5 Juno II / AM-11 U.S. NASA / ABMA lunar flyby U 1959 Luna 1 Ye-1 / 4 361.3 kg 01-02-59 / 16:41:21 NIIP-5 / 1 Luna / B1-6 USSR OKB-1 lunar impact P Master Table of All Deep Space, Lunar, andPlanetary Probes1958–2000 ofAllDeepSpace,Lunar, Master Table Pioneer 4 - 6.1 kg 03-03-59 / 05:10:45 ETR / 5 Juno II / AM-14 U.S.
    [Show full text]
  • Collezione Per Genova
    1958-1978: 20 anni di sperimentazioni spaziali in Occidente La collezione copre il ventennio 1958-1978 che è stato particolarmente importante nella storia della esplorazio- ne spaziale, in quanto ha posto le basi delle conoscenze tecnico-scientifiche necessarie per andare nello spa- zio in sicurezza e per imparare ad utilizzare le grandi potenzialità offerte dallo spazio per varie esigenze civili e militari. Nel clima di guerra fredda, lo spazio è stato fin dai primi tempi, utilizzato dagli Americani per tenere sotto con- trollo l’avversario e le sue dotazioni militari, in risposta ad analoghe misure adottate dai Sovietici. Per preparare le missioni umane nello spazio, era indispensabile raccogliere dati e conoscenze sull’alta atmo- sfera e sulle radiazioni che si incontrano nello spazio che circonda la Terra. Dopo la sfida lanciata da Kennedy, gli Americani dovettero anche prepararsi allo sbarco dell’uomo sulla Luna ed intensificarono gli sforzi per conoscere l’ambiente lunare. Fin dai primi anni, le sonde automatiche fecero compiere progressi giganteschi alla conoscenza del sistema solare. Ben presto si imparò ad utilizzare i satelliti per la comunicazione intercontinentale e il supporto alla navigazio- ne, per le previsioni meteorologiche, per l’osservazione della Terra. La Collezione testimonia anche i primi tentativi delle nuove “potenze spaziali” che si avvicinano al nuovo mon- do dei satelliti, che inizialmente erano monopolio delle due Superpotenze URSS e USA. L’Italia, con San Mar- co, diventò il terzo Paese al mondo a lanciare un proprio satellite e allestì a Malindi la prima base equatoriale, che fu largamente utilizzata dalla NASA. Alla fine degli anni ’60 anche l’Europa entrò attivamente nell’arena spaziale, lanciando i propri satelliti scientifici e di telecomunicazione dalla propria base equatoriale di Kourou.
    [Show full text]
  • To Delta-Based Bidirectional Model Transformations: the Symmetric Case
    From State- to Delta-based Bidirectional Model Transformations: the Symmetric Case Zinovy Diskin1, Yingfei Xiong1, Krzysztof Czarnecki1, Hartmut Ehrig2, Frank Hermann2;3, and Fernando Orejas4 1 Generative Software Development Lab, University of Waterloo, Canada fzdiskin,yingfei,[email protected] 2 Institut f¨urSoftwaretechnik und Theoretische Informatik, Technische Universit¨atBerlin, Germany, [email protected] 3 Interdisciplinary Center for Security, Reliability and Trust, Universit´edu Luxembourg, [email protected] 4 Departament de Llenguatges i Sistemes Inform`atics, Universitat Polit`ecnicade Catalunya, Barcelona, Spain, [email protected] Abstract. A bidirectional transformation (BX) keeps a pair of interre- lated models synchronized. Symmetric BX are those for which neither model in the pair fully determines the other. We build two algebraic frameworks for symmetric BXs, with one correctly implementing the other, and both being delta-based generalizations of known state-based frameworks. We identify two new algebraic laws|weak undoability and weak invertibility, which capture important semantics of BX and are use- ful for both state- and delta-based settings. Our approach also provides a flexible tool architecture adaptable to different user's needs. 1 Introduction Keeping a system of models mutually consistent (model synchronization) is vital for model-driven engineering. In a typical scenario, given a pair of inter-related models, changes in either of them are to be propagated to the other to restore consistency. This setting is often referred to as bidirectional model transforma- tion (BX) [3]. As noted by Stevens [15], despite early availability of several BX tools on the market, they did not gain much user appreciation because of semantic issues.
    [Show full text]
  • Quarterly Launch Report
    Commercial Space Transportation QUARTERLY LAUNCH REPORT Featuring the launch results from the previous quarter and forecasts for the next two quarters 1st Quarter 1998 U n i t e d S t a t e s D e p a r t m e n t o f T r a n s p o r t a t i o n • F e d e r a l A v i a t i o n A d m i n i s t r a t i o n A s s o c i a t e A d m i n i s t r a t o r f o r C o m m e r c i a l S p a c e T r a n s p o r t a t i o n QUARTERLY LAUNCH REPORT 1 1ST QUARTER 1998 REPORT Objectives This report summarizes recent and scheduled worldwide commercial, civil, and military orbital space launch events. Scheduled launches listed in this report are vehicle/payload combinations that have been identified in open sources, including industry references, company manifests, periodicals, and government documents. Note that such dates are subject to change. This report highlights commercial launch activities, classifying commercial launches as one or more of the following: • Internationally competed launch events (i.e., launch opportunities considered available in principle to competitors in the international launch services market), • Any launches licensed by the Office of the Associate Administrator for Commercial Space Transportation of the Federal Aviation Administration under U.S.
    [Show full text]
  • The Evolution of Commercial Launch Vehicles
    Fourth Quarter 2001 Quarterly Launch Report 8 The Evolution of Commercial Launch Vehicles INTRODUCTION LAUNCH VEHICLE ORIGINS On February 14, 1963, a Delta launch vehi- The initial development of launch vehicles cle placed the Syncom 1 communications was an arduous and expensive process that satellite into geosynchronous orbit (GEO). occurred simultaneously with military Thirty-five years later, another Delta weapons programs; launch vehicle and launched the Bonum 1 communications missile developers shared a large portion of satellite to GEO. Both launches originated the expenses and technology. The initial from Launch Complex 17, Pad B, at Cape generation of operational launch vehicles in Canaveral Air Force Station in Florida. both the United States and the Soviet Union Bonum 1 weighed 21 times as much as the was derived and developed from the oper- earlier Syncom 1 and the Delta launch vehicle ating country's military ballistic missile that carried it had a maximum geosynchro- programs. The Russian Soyuz launch vehicle nous transfer orbit (GTO) capacity 26.5 is a derivative of the first Soviet interconti- times greater than that of the earlier vehicle. nental ballistic missile (ICBM) and the NATO-designated SS-6 Sapwood. The Launch vehicle performance continues to United States' Atlas and Titan launch vehicles constantly improve, in large part to meet the were developed from U.S. Air Force's first demands of an increasing number of larger two ICBMs of the same names, while the satellites. Current vehicles are very likely to initial Delta (referred to in its earliest be changed from last year's versions and are versions as Thor Delta) was developed certainly not the same as ones from five from the Thor intermediate range ballistic years ago.
    [Show full text]
  • NTSB Aircraft Accident Report
    c PB86-910406 / L NATIONAL * TRANSPORTATION SAFETY BOARD WASHINfSTON, D.C. 20594 AIRCRAFT ACCIDENT REPORT DELTA AIR LINES, INC., LOCKHEED L-101 l-385-1, N726DA DALLAS/FORT WORTH - INTERNATIONAL AIRPORT, TEXAS AUGUST 2,1985 NTSBIAAR-86/05 UNITED STATES. .-. GOVERNMENT REPRODUCE0 BY - - - U.S. DEPARTMENT DF COMMERCE NATIONAL TECHNICAL INFORMATION SERVICE SPRINC3FIELD. VA. 22161 -. -_ .__ TECHNICAL- -----_--- -- -.-. REPORT ---- ----.. DOCUMENTATTfIN --. --.. PAGF. ..-- I Report No. Z.Government Accession No. 3.Recipient’s Catalog No. ‘NTSB/AAR-86IOj PB86-910406 4 Title and Subti tie Aircraft .Accldent K t--uelta 5.Report Date ‘Air Lines, Inc., Lockheed L-loll-385-1, N’7‘ii%fi, August 15, 1986 Dallas/Fort i\;ortll International Airport, Texas, 6.Performing Organization Auplst 2, 1985 Code 7. Author(s) 8.Performing Organization Report No. 9. Performing Organization Name and Address 10.Woqr3k2i;i t No. National Transportation Safety ijoard d Rurcau of Accident Investigntmn ll.Contract or Grant No. Washington, D.C. 20594 13.Type of Report and Period Covered 12.Sponsoring Agency Name and Address Aircraft Accident Beport August 2, 1985 NATIONAL TRANSPORTATION SAFETY BOARD Washington, D. C. 20594 14.Sponsoring Agency Code ls.Supplementary Notes 16.Abstract On August 2, 1’385, at 1805:52 central daylight -time, Delta Air Lines flight 1 Y 1, a Lockheed L-1011-385-1. UTZliDA, crashed while,approaching to land on runway 1SL at tile Dallas Fort CVorth International Airport, Texas. (While passing through the rain shaft beneath a thuflderstor:n, flight lY1 entered a inicroburst which the pilot was unabie to traverse successfuliy. The airplane struck the ground about 6,300 feet north of the approach end of runway 1’7L, hit a car on a highway north of the runway killing the driver, struck two water tanks.
    [Show full text]
  • A Brazilian Space Launch System for the Small Satellite Market
    aerospace Article A Brazilian Space Launch System for the Small Satellite Market Pedro L. K. da Cás 1 , Carlos A. G. Veras 2,* , Olexiy Shynkarenko 1 and Rodrigo Leonardi 3 1 Chemical Propulsion Laboratory, University of Brasília, Brasília 70910-900, DF, Brazil; [email protected] (P.L.K.d.C.); [email protected] (O.S.) 2 Mechanical Engineering Department, University of Brasília, Brasília 70910-900, DF, Brazil 3 Directorate of Satellites, Applications and Development, Brazilian Space Agency, Brasília 70610-200, DF, Brazil; [email protected] * Correspondence: [email protected] Received: 8 July 2019; Accepted: 8 October 2019; Published: 12 November 2019 Abstract: At present, most small satellites are delivered as hosted payloads on large launch vehicles. Considering the current technological development, constellations of small satellites can provide a broad range of services operating at designated orbits. To achieve that, small satellite customers are seeking cost-effective launch services for dedicated missions. This paper deals with performance and cost assessments of a set of launch vehicle concepts based on a solid propellant rocket engine (S-50) under development by the Institute of Aeronautics and Space (Brazil) with support from the Brazilian Space Agency. Cost estimation analysis, based on the TRANSCOST model, was carried out taking into account the costs of launch system development, vehicle fabrication, direct and indirect operation cost. A cost-competitive expendable launch system was identified by using three S-50 solid rocket motors for the first stage, one S-50 engine for the second stage and a flight-proven cluster of pressure-fed liquid engines for the third stage.
    [Show full text]
  • Press Kit , Project ~Arisat-B RELEASE NO: 7643
    https://ntrs.nasa.gov/search.jsp?R=19760070167 2020-03-22T12:05:44+00:00Z View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by NASA Technical Reports Server ! News National Aeronautics and Space Administration Washrngton. D.C.20546 AC 202 755-8370 * For Release IMMEDIATE Press Kit , Project ~arisat-B RELEASE NO: 7643 Contents , GENERAL RE&EASE........:.....e...................... 1-3 DELTA LAUNCH VEHICLEoooo...o........oom....a...o.o. 4 STRAIGH$-SIGHT DELTA FACTS AND FIGURES. ............ 5-6 TYPICAL LAUNCH SEQUENCE FOR MARISAT-B ...............7-8 LAUNCH OP&~TIONS,..........................:...... 9 'NASA TEAM...................^.^..^.^.^..^.^^^ 9-10 COMSAT GENERAL CORP.,.............................. 11 ---- ---- -- -- - - -- - - - - - - .- (111SA-lleus-Release-76-83) . NASA TOLAUNCH SECOND BABISAT POB COBSAT GENERAL COOP- (NASA) 12 p Unclas 43127 N!News National Aeronautics and Space Administration' .> t r I Washington, 0.C.20546 I) AC 202 755-8310 For Release: ' Bill O'bonnell Headquarters, Washington, D.C. IMMEDIATE (Phone: 202/73518487) .. +. 4.: RELEASE NO: 76-83 NASA TO LAUNCH SECOND .~RISATFOR COMSAT GENBRAL,CORP. The 98cond maritime satellite (Marisat) will be launched a ,' by NASA for COMSAT General Corp. from Cape Canaveral, Fla., about May 27. 1, The spacecraft will be the second in the new Marisat system designed to provide communications t6 the :u.s. Navy, commercial shipping and offshore industries. I , Marisat-B will be il'alaced into synchronous orbit. over' the equator above the Pacific Ocean at 176.5 degrees W, longitude just west of Hawaii. A third Marisat has been t built as a spare. The first spacecraft, Marisat-1, was launched success- fully Feb.
    [Show full text]
  • Investigation of Combustion Instability in a Single Annular Combustor
    University of Cincinnati Date: 10/29/2010 I, Fumitaka Ichihashi , hereby submit this original work as part of the requirements for the degree of Master of Science in Aerospace Engineering. It is entitled: Investigation of Combustion Instability in a Single Annular Combustor Student's name: Fumitaka Ichihashi This work and its defense approved by: Committee chair: San-Mou Jeng, PhD Committee member: Shanwu Wang, PhD Committee member: Kelly Cohen, PhD Committee member: Asif Syed, PhD 1304 Last Printed:3/4/2011 Document Of Defense Form Investigation of Combustion Instability in a Single Annular Combustor A thesis submitted to the Graduate School of the University of Cincinnati in partial fulfillment of the requirements for the degree of Master of Science in the Department of Aerospace Engineering and Engineering Mechanics of the College of Engineering Nov 2010 by Fumitaka Ichihashi B.S., Aerospace Engineering, University of Cincinnati, USA Committee Chair: Dr. San-Mou Jeng Abstract The well known criterion for combustion instability is called the Rayleigh‘s criterion. It indicates that, for combustion instability to occur, the heat release rate (q‘) and pressure oscillation (p‘) must be in phase. This thesis describes measurement techniques and study methods for combustion instabilities that occurred in the prototype single annular sector Rich-Burn Quick-Mix Lean-Burn (RQL) combustor on the original (short) and new (long) experimental rig configuration with a focus on q‘ and p‘ measurements. A change in the configuration of the combustor rig was necessary in order to acquire more precise measurements of forward- and backward-moving acoustic pressure waves within the rig by mounting pressure transducers on preselected locations of the upstream duct, downstream duct and combustion area.
    [Show full text]
  • THE BASICS of COLOR PERCEPTION and MEASUREMENT the Basics of Color Perception and Measurement
    THE BASICS OF COLOR PERCEPTION AND MEASUREMENT The Basics Of Color Perception and Measurement This is a tutorial about color perception and measurement. It is a self teaching tool that you can read at your own pace. When a slide has all information displayed, the following symbols will appear on the lower left side of the screen To go back one slide click. To advance one slide click. To exit the presentation press the Escape key on your keyboard. Contents There are five sections to this presentation: Color Perception Color Measurement Color Scales Surface Characteristics and Geometry Sample Preparation and Presentation If you wish to jump to a specific section click above on the appropriate name or click below to advance to the next slide. COLOR PERCEPTION Things Required To See Color A Light Source An Object An Observer Visual Observing Situation LIGHT SOURCE OBSERVER OBJECT Visual Observing Situation The visual observing model shows the three items necessary to perceive color. To build an instrument that can quantify human color perception, each item in the visual observing situation must be represented as a table of numbers. Light Source Light Source A light source emits white light. When light is dispersed by a prism, all visible wavelengths can be seen. Sunlight Spectrum Light Source Visible light is a small part of the electromagnetic spectrum. The wavelength of light is measured in nanometers (nm). The CIE wavelength range of the visible spectrum is from 360 to 780 nm. A plot of the relative energy of light at each wavelength creates a spectral power distribution curve quantifying the characteristics of the light source.
    [Show full text]
  • Distributed $(\Delta+1)$-Coloring Via Ultrafast Graph Shattering | SIAM
    SIAM J. COMPUT. \bigcircc 2020 Society for Industrial and Applied Mathematics Vol. 49, No. 3, pp. 497{539 DISTRIBUTED (\Delta + 1)-COLORING VIA ULTRAFAST GRAPH SHATTERING\ast y z x YI-JUN CHANG , WENZHENG LI , AND SETH PETTIE Abstract. Vertex coloring is one of the classic symmetry breaking problems studied in distrib- uted computing. In this paper, we present a new algorithm for (\Delta +1)-list coloring in the randomized 0 LOCAL model running in O(Detd(poly log n)) = O(poly(log log n)) time, where Detd(n ) is the de- 0 terministic complexity of (deg +1)-list coloring on n -vertex graphs. (In this problem, each v has a palette of size deg(v)+1.) This improves upon a previousp randomized algorithm of Harris, Schneider,p and Su [J. ACM, 65 (2018), 19] with complexity O( log \Delta +log log n+Detd(poly log n)) = O( log n). Unless \Delta is small, it is also faster than the best known deterministic algorithm of Fraigniaud,Hein- rich, and Kosowski [Proceedings of the 57th Annual IEEE Symposium on Foundations of Com- puter Science (FOCS), 2016] and Barenboim, Elkin, and Goldenberg [Proceedings of the 38th An- nualp ACM Symposium on Principles of Distributed Computing (PODC), 2018], with complexity O( \Delta log \Deltalog\ast \Delta +log\ast n). Our algorithm's running time is syntactically very similar to the \Omega (Det(poly log n)) lower bound of Chang, Kopelowitz, and Pettie [SIAM J. Comput., 48 (2019), pp. 122{143], where Det(n0) is the deterministic complexity of (\Delta + 1)-list coloring on n0-vertex graphs.
    [Show full text]
  • ROCKETS and MISSILES Recent Titles in Greenwood Technographies
    ROCKETS AND MISSILES Recent Titles in Greenwood Technographies Sound Recording: The Life Story of a Technology David L. Morton Jr. Firearms: The Life Story of a Technology Roger Pauly Cars and Culture: The Life Story of a Technology Rudi Volti Electronics: The Life Story of a Technology David L. Morton Jr. ROCKETS AND MISSILES 1 THE LIFE STORY OF A TECHNOLOGY A. Bowdoin Van Riper GREENWOOD TECHNOGRAPHIES GREENWOOD PRESS Westport, Connecticut • London Library of Congress Cataloging-in-Publication Data Van Riper, A. Bowdoin. Rockets and missiles : the life story of a technology / A. Bowdoin Van Riper. p. cm.—(Greenwood technographies, ISSN 1549–7321) Includes bibliographical references and index. ISBN 0–313–32795–5 (alk. paper) 1. Rocketry (Aeronautics)—History. 2. Ballistic missiles—History. I. Title. II. Series. TL781.V36 2004 621.43'56—dc22 2004053045 British Library Cataloguing in Publication Data is available. Copyright © 2004 by A. Bowdoin Van Riper All rights reserved. No portion of this book may be reproduced, by any process or technique, without the express written consent of the publisher. Library of Congress Catalog Card Number: 2004053045 ISBN: 0–313–32795–5 ISSN: 1549–7321 First published in 2004 Greenwood Press, 88 Post Road West,Westport, CT 06881 An imprint of Greenwood Publishing Group, Inc. www.greenwood.com Printed in the United States of America The paper used in this book complies with the Permanent Paper Standard issued by the National Information Standards Organization (Z39.48–1984). 10987654321 For Janice P. Van Riper who let a starstruck kid stay up long past his bedtime to watch Neil Armstrong take “one small step” Contents Series Foreword ix Acknowledgments xi Timeline xiii 1.
    [Show full text]