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Effects, Color .Level Ot Detail, Surce Definition, Perceived 1.7 DOCUNEIT RESONE NO 208 851 IR 009 760 -. i , AUTHOR Stenger, Anthony.J.; And Others TITLE ,Advanded Computer Image _Generation Techniques Exploiting Perceptual:Characteristics..Finai . Report. INSTITUTION :Technology Service Corp., Santa'Monica, Calif. SPONS AGENCY 'Air Force Human Resources Lab., Brooks AFB, Texas. REPORT NO APHRL-TR-80-61 '* V ) .. .PUB DATE , Aug 81 4 CONTRACT * . F33615-78-C-0020 ROTE 329p. IDES PRICE MT01/PC14 Plus Postage. DESCRIPTORS ,. *Algorithms; *Computer Graphics; Computers; Electronic Equipment; -*Input Output'DeVices; Perceptual Development; *Simulation; *Ulu? Aids; *Visual .Perception ABSTRACT Thisstudy suggests and identifies computer image generation (CIG) algorithms for 'visual simulation that improvethe 'training effectiveness of CIG simulators hnd identifiesareas of ,basic research "in visual perception that are significant for . improving CIG technology. The first phase of the project entailed observing,t4gee existing CIG' simulators. During the second phaie4 existing per:Septual knowledge was studied in light of the capabilities nd limitations,of existing CIG simulators. The analysis resulted in-4 list of 12 perCeptual limitations of these CIG f simulators wh ch include contrast management and aerial perspective,' resoluttor-dyn mic range, directional illumination effects, raster 'effectS, color .level ot detail, surce definition, perceived flatness of the display, minital scene content, size and continuity of the visual f eld, and hyhriAdispla4 and update. In the third phase, improved\1CsIG algorithms were developed in the areas of aliasing sontrolr-sceneienytronsent and sensor models, display properties, and future algorithms in high density of features and reflection models. Further research is recommended in sevenareas of perceptdal research and. in five areas for algorithm research. A. bibliography of 38 references' and appendices containing4onsAltant --intervieWs° and literature summaries are included. (CHC) # **$c******4.**************************************4!******************1**** * Re'prodUctIons supplied by EDIIS,a;e the best thatcan made *- , . be . * ':' from the original dochment. * *****44*t*****p******************************************************** _ , . - , . .....t US DEPARTMENT OF H i ALIN. AF11111,-T -80-6 I EDUCATION i WELFARE NATIONAL INSTITUTE OF EDUCATION 0 ' _THIS DOCUMENT HASBEEN REPRO. OUCEO EXACTLY AS RECEIVEDFROM THE PERSON OR ORGANIZATIONORIGIN ATING IT POINTS Of VIEW OROPINIONS STATED 00 NOT NECESSARILYREPRE SENT OFFICIAL NATIONAL INSTITUTEOF AIR FORC EOUCATION POSITION OR POLICY 1D\ 1N,CED CO.MPl. TER IMAGE GENERATIONTECIINIQ1. ES. EXPLOITING PERCIA4TLAL CHARACTERISTICS Anthony J. Stenger Iii A. immerlin James P. Thomas '\B roil Braunstein I veil nolow. `it.ict. ( ogps)ratioit 2950 - 31.1 tit reel (.alifortii 11)3 4 OPERATIONSTR AINI NG DIVISION Williams Air Force Base. Arizona 85221 R . r.... E1 August 1981 S , Final Report .. U 1,,,,r0,441for poblie'rleae. (11.1riloolooonlimitefl ..) C E., S .LABORATORY AIR FORCE SYSTEMS COMMAND BROOKS AIR FORCE BASE,TEXAS 78235 4(1 O NOTICE I When Government drawings. specifications.'orother data are used fur an) purpose other than inconnection with adefinitlsGovernment- related procurement. thet nitedStates Government incurs no respo7nsibilt)or am obligation whatsoever. The 4act that the Government eras have formulated or in answ a) supplied the said drawings. specifications. ur other data. is not to be regarded bs implication, or otherwise inanmanner construed. as, licensing the holder, or ans other person or corporation:or as conves an rights or permission to manufacture. use. or sell ans patented in%ention thatwas in an was be related, thereto. d This report was.. subinitt4 bs the Technology Service Corporation. 295I- 31.4 Street. Santa Monica. California 90405 under Contract F33615-78-C-0020.Project 6114. withthe Operations Training Division. Air Force Human Re..ources Laboratory (AFSC). V illiamskir hie Force Base.krizona 85221. Major, George Buckland was the Contract Monitor for the Laboratory , The Public kit-airs Office has resiewed this report. and itis releasable to the National Technical Information Service. where it will be mailable to the general_ public. including foreign nationals. Thi's report has beim reviewed and is approved for publication. MILTON E. V. 00Q. Technical Director Operations Training Division RONALD W. TERRY. Colonel. USAF Commander PREFACE .4- This study was accomplished to suggest advanced computerimage generation (CIG)techniques which will exploittthe capabilities/limitations of the human visual perceptual processing system and improve'lhetraining effectiveness of visual simulation systems. The secondary objktiveof this effort is to identify areas of basic perceptual research tnatpromise to haVe significant impact on(ftiture CIG technology.' This reportshould be of valve_to anyone involved in real-time visual simulation-usingcom-, puter image generation. This stud' was trformed for the AirForce Human Resources Laboratory' under contract F33615-78-C-0020: Mr. Michael Nicol was thecontract monitor . for the Air Force, and Mr.Anthony Stenger was'the programmanager for Technology Service Corporation. Dr. James P. Thomas of theUniversityof Californiaat Los Angeles and.Dr: Myron Braunstein of, the Universityof California at Irvine performed all the work in the perceptualarea. Mr. Timothy A. Zimmerlin contributed the materialon CIG algorithms and systems.¶Mr. Thomas Murray of the University of California atLos Angele and Mr. Jack Schryver of the University of California atIrvine perUippeg \the literature search and prep'aredthesummaries. .. 4 TABLE OF CONTENTS Section ". .; 1. INTRODUCTION 7 1.1 OBJECTIVES 7 1.2 APPROACH 8 1.3 RESULTS 9 1.4 RECOMMENATIONS 10. , 2. PERCEPTUAL LIMITATIONS OF EXISTING CIG SIMULATORS 14 2.1 CONTRAST MANAGEMENT'ANDAERIAL PERSPECTIVE 16 2.2. RESOLUTION' '', . 21 2.2.1 Detection and Identification 21 2.2.2 Judgments Of Position, Size, and Orientation 22 '2.2.3 ,.Ralism- 24 t 2.3 DYNAMIC RANGE 25 2.3.1 Remedial Steps f 26 2.3.2 Relevant Literature 27 2.4 DIRECTIONAL ILLUMINATION EFFECTS 27 2.5 +RASTER EFFECTS 7 28 2.6 COLOR ,30 . 2.7 LEVEL OF DETAIL - 30 2.8 SURFACE DEFINITION , 31 2.9 PERCEIVEVFLATNESS OF THE DISPLAY 36 2.10 MINIMAL SCENE CONTENT % 37 2.11 SIZE AND CONTINUITY OF THE VISUAL FIELD 40 2.12 HYBRID DISPLAY AND UPDATE RATE 41 3, ADVANCED ALGORITHMS RELATING TO LIMITATIONS ,. 43 3.1 ALIASING CONTROLS 1 43 , 1.1.1 Ga.ussian Impulse Response 44 4 3.1.2 Frame/Field Conditions 49 3.1.3 Hybrid Picture Effects , ..6 52 3.2 ,. SCENE, ENVIRONMENT, AND SENSOR MODELS 53 3.2.1 Atmospheric Attenuation and Scattering 54 3.2.2 Toni Application Methods 59 3.2.3 1 Reflection Models 64 3.2.4 Level-of-DetaiLContrors . : 65 3.3 DISPLAY PROPERTIES 6 66 3.3.1 Display Face - I 66 1 '3.3.2 Contrast Management , . .. .. 67. 3.4 FUTURE ALGORITHMS 68 3.4.1" High Density of ,Features 70 - 3.4.2 Reflection Models 70 a 0 3 C TABLE OF CONTENTS (continued) Section 4. ,,RECOMMENDED RESEARCH AREAS 71 4.1 AREAS PERCEPTUAL RESEARCH' 71 4.1.1 A rial Perspective 73'' 4.1.2 Texture 74 4,1.3 Shadows 76- 4.1.4 Specular Reflection 78 4.1.5- Flaaess Cues 79. 4.1.6 Perceived. Self- Motion. 80 4.1.7 Update Rate, 4 , 81 4.2 AREAS FOR ALGORITHM RESEARCH. 82*. 4.2.1 Smooth Shading 83 4.2.2 Textured Shading 84 4.2.3 Shadows 85 4.2.4 General Reflection 85 4.2.5 Contrast Management 86 REFERENCE!: 87-89 2 Appendix A. Consultant Interviews 91) B. Literature Summaries 107 4 ' LIST OF FIGURES Figure 1. Perceptual Illusions 33 2. Examples of Constant and Gaussian Weights 45 -3. Convolution of Human Response and Display 47 4. Point Light Using Uniform Weighting 48 5. Perceived Effect of Displaying Each Frame Twice f . 5'1 6. Effect Scattering and Need fora Defocusing Model --,----57 7. Perspective Effects on Linear; Interpolation lk of Surface Tones 61 8. Geometry of Inverse Range Shading , 63 9. Unfiltered and High:Pass Filtered Tonal Ranges . .. 69. 1 *am 4. 5 r 4 I 1 1. INTRODUCTION This final report documents a study that.Technology Service Corporation (TSC) completed for the Air Force Human ResoUrces Laboratory. The report is structured to parallel the prijgress of the individual project phases. This firsesection introduces the project and provides a summary by discussing the project's objective, approach, results, and recommendations. The remaining sections present the findings of the project in greaterdetail. The information is intended for computer image generation ,(CIG) system designers, data base constructors, psychologists, and training p&sonne). 1 .1 OBJECTIVES . The study objectives involve applying psychological knowledge of vistr61"' perception to,improvereal-time CIG simulators. The primary objec- tive is to suggest and identify Vg7;i777thms for visual simulation that improve the training effectiveness of CIG simulators. The secondary objective is to\identify areas of basic research in visual perception that are significant for improving CIG technology. The objectives of the'project have been met. A numbj of CIG algorithmsare described in this report, most of which can be applied to existing Simulators with only slight'modifications to the simulators' basic, designs. SomealgAithmsinvolve the scene and environment models and require no hardware modifications. A few algorithms impact the display requirements of future CIG simulators. The algorithms were suggested?yobserving the perceptual limitations of existing CIG simulators..The perceptual objectives were further met by 1. Categorizing
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