CS452/552; EE465/505. Color Display Issues


 Stuart Rodgers
 9 months ago
 Views:
Transcription
1 CS452/552; EE465/505 Color Display Issues
2 2
3 Outline! Color Display Issues Color Systems Dithering and Halftoning! Splines Hermite Splines Bezier Splines CatmullRom Splines Read: Angel, Chapter 8, section 8.13 Display Considerations Chapter 11, Curves and Surfaces Chapter 12, section Advanced Rendering: RayTracing Lab#5 posted, due: April 22nd simple scene: platform & object; 1 light; shadow map; camera controls Project#2 posted due: April 23rd
4 Light mapping
5 Recursive Ray Tracer (Simple version) // starting point p, direction d, max # of steps; returns a color c (single light source) trace(p, d, step) { color local, reflected, transmitted; point q; normal n; if(step > max) return(background_color); q = intersect(p, d, status); if(status==light_source) return(light_source_color); if(status==no_intersection) return(background_color); n = normal(q); r = reflect(q, n); t = transmit(q,n); local = phong(q, n, r); reflected = trace(q, r, step+1); // recursive call transmitted = trace(q, t, step+1); // recursive call return(local + reflected + transmitted); }
6 Ray Tracing: Summary! Efficiency replace the recursion with iteration use bounding boxes to simplify the math used to compute intersections! Aliasing errors, due to sampling use a stochastic sampling method in which the decision on where to cast the next ray is based on the rays cast so far (used in Renderman)! Ray tracing is an inherently parallel process! There are many free ray tracers available
7 Next Topic: Displays & Color! Consider perceptual issues related to displays! Introduce chromaticity space Color systems Color transformations! Standard Color Systems Angel and Shreiner: Interactive Computer Graphics 7E AddisonWesley 2015
8 Displays & Color! Problems that affect the quality of a display two different displays may have the same resolution, but display pixels at different sizes the colors displayed on two different monitors may differ map softwaredefined colors onto the display map brightness values onto the display RGB values are independent of display properties, but do not account for the full range of the human visual system! The range of displayable colors for a device is called its color gamut
9 Luminance and Color Images! Luminance Image Monochromatic Values are gray levels Analogous to working with black and white film or television! Color Image Has perceptional attributes of hue, saturation, and lightness Do we have to match every frequency in visible spectrum? No! E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
10 Perception Review! Light is the part of the electromagnetic spectrum between ~ nm! A color C(λ) is a distribution of energies within this range! Human visual system has two types of sensors Rods: monochromatic, night vision Cones: color sensitive Three types of cones! Consequently, only three values, the tristimulus values, are perceived by the brain E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
11 Color vision deficiency! redgreen difficulty distinguishing between shades of red + green affects ~8% of males and ~0.5% of females in populations of North European ancestry! blueyellow difficulty differentiating shades of blue and yellow affects males & females equally, < 1/10,000! achromatopsia cannot perceive any colors rare, < 1/30,000 for most populations
12 Tristimulus Values! The human visual center has three cones with sensitivity curves S 1 (λ), S 2 (λ), and S 3 (λ)! For a color C(λ), the cones output the tristimulus values T = S λ) C( λ) dλ 1 1 ( C(λ) T = S λ) C( λ) dλ 2 2 ( T = S λ) C( λ) dλ 3 3 ( cones optic nerve T 1, T 2, T 3 E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
13 Three Color Theory! Any two colors with the same tristimulus values are perceived to be identical! Thus a display (CRT, LCD, film) must only produce the correct tristimulus values to match a color! Is this possible? Not always Different primaries (different sensitivity curves) in different systems E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
14 The Problem! The sensitivity curves of the human are not the same as those of physical devices! Human: curves centered in blue, green, and greenyellow! CRT: RGB! Print media: CMY or CMYK! Which colors can we match and, if we cannot match, how close can we come? E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
15 Representing Colors! Consider a color C(λ)! It generates tristimulus values T 1, T 2, T 3 Write C = (T 1, T 2, T 3 ) Conventionally,we assume 1 T 1, T 2, T 3 0 because there is a maximum brightness we can produce and energy is nonnegative 1 C is a point in color solid C 1 T 3 T 2 T 1 1 E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
16 Producing Colors! Consider a device such as a CRT with RGB primaries and sensitivity curves! Tristimulus values T = R( λ) C( λ) dλ T = G( λ) C( λ) dλ T = B( λ) C( λ) dλ E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
17 Matching! This T 1, T 2, T 3 is dependent on the particular device! If we use another device, we will get different values and these values will not match those of the human cone curves! Need a way of matching and a way of normalizing E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
18 Color Systems! Various color systems are used Based on real primaries: RGB UVW CMYK HLS (aka HSB) NTSC YIQ (National Television System Committee) Theoretical XYZ! Prefer to separate brightness (luminance) from color (chromatic) information Reduce to two dimensions E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
19 Tristimulus Coordinates! For any set of primaries, define t = T T T Note: T t 3 = T T T t = T T T T 3 T + + 1,, 0 t t t = 1 t t 2 t E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
20 Maxwell Triangle 1 T 1 + T 2 +T 3 =1 1 1 color solid Project onto 2D: chromaticity space 1 t 1 + t 2 =1 t 1 possible colors t 2 1 E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
21 NTSC RGB 1 r+g+b=1 g r+g=1 r 1 E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
22 Producing Other Colors! However colors producible on one system (its color gamut) is not necessarily producible on any other! Note that if we produce all the pure spectral colors in the nm range, we can produce all others by adding spectral colors! With real systems (CRT, film), we cannot produce the pure spectral colors! We can project the color solid of each system into chromaticity space (of some system) to see how close we can get E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
23 Color Gamuts 600 nm spectral colors CRT colors printer colors producible color on CRT but not on printer unproducible color 350 nm producible color on both CRT and printer 750 nm E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
24 XYZ! Reference system in which all visible pure spectral colors can be produced! Theoretical systems, as there are no corresponding physical primaries! Standard reference system E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
25 Color Systems! Most correspond to real primaries National Television Systems Committee (NTSC) RGB matches phosphors in CRTs! Film both additive (RGB) and subtractive (CMY) for positive and negative film! Print industry CMYK (K = black) K used to produce sharp crisp blacks Example: ink jet printers E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
26 Color Transformations! Each additive color system is a linear transformation of another G G C = (T 1, T 2, T 3 ) = (T 1, T 2, T 3 ) B B R in R G B system R in RGB system E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
27 Additive and Subtractive Color! Additive color Form a color by adding amounts of three primaries CRTs, projection systems, positive film Primaries are Red (R), Green (G), Blue (B)! Subtractive color Form a color by filtering white light with cyan (C), Magenta (M), and Yellow (Y) filters Lightmaterial interactions Printing Negative film E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
28 RGB: Red, Green, Blue! Primary colors: red, green, blue! Secondary colors: yellow = red+green cyan = green+blue magenta = blue+red! All colors white = red+green+blue black = no color C = T 1 R + T 2 G + T 3 B Color Cube
29 CMYK: Cyan, Magenta, Yellow, Black! Primary colors: cyan, magenta, yellow! Secondary colors: blue = cyan+magenta red = magenta+yellow green = yellow+cyan! All colors white = no color black = cyan+magenta+yellow for true black, add in black (+black) Also known as process color (used to print fullcolor images)
30 RGB, CMY, CMYK! Assuming 1 is max of a primary C = 1 R M = 1 G Y = 1 B! Convert CMY to CMYK by K = min(c, M, Y) C = C K M = M K Y = Y  K E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
31 Color Matrix! Exists a 3 x 3 matrix to convert from representation in one system to representation in another # &! $! = M$! $ " %! Example: XYZ to NTSC RGB find in colorimetry references & $ $ $ % T' T' T' T T T! Can take a color in XYZ and find out if it is producible by transforming and then checking if resulting tristimulus values lie in (0,1) #!!! " E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
32 YIQ! NTSC Transmission Colors! Here Y is the luminance arose from the need to separate brightness from chromatic information in TV broadcasting & Y# $! $ I! $ % Q! " = & $ $ $ % #& R# ! $!! $ G! 0.311!" $ % B! "! Note luminance shows high green sensitivity E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
33 Other Color Systems! UVW: equal numerical errors are closer to equal perceptual errors! HLS: perceptual color (hue, saturation, lightness) Polar representation of color space Single and double cone versions E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
34 HSB: Hue, Saturation, Brightness! Hue is the actual color. It is measured in angular degrees counterclockwise around the cone starting and ending at red=0 or 360 (yellow = 60, green = 120, etc.).! Saturation is the purity of the color, measured in percent from the center of the cone (0) to the surface (100).! Brightness is measured in percent from black (0%) to white (100%). grayscale axis from 0% (white) to 100% (black)
35 Gamma Correction! Intensity vs CRT voltage is nonlinear I = cv γ! Gamma correction (encoding) can code/decode luminance or tristimulus values! Can use a lookup table to correct! Human brightness response is logarithmic Equal steps in gray levels are not perceived equally Can use lookup table! CRTs cannot produce a full black Limits contrast ratio E. Angel and D. Shreiner: Interactive Computer Graphics 6E AddisonWesley 2012
36 Dithering (digital halftoning)
37 Black/White Dithering
38 Color Dithering
39 Halftoning
40 Modeling Complex Shapes
41 What do we need from curves in Computer Graphics?! Local control of shape so that it is easy to build and modify! Stability! Smoothness and continuity! Ability to evaluate derivatives! Ease of rendering
42 Utah Teapot! Most famous data set in computer graphics! Widely available as a list of 306 3D vertices and the indices that define 32 Bezier patches
43 Curve Representations
44 Parameterization of a Curve
45 Polynomial Interpolation
46 Splines: Piecewise Polynomials
47 Piecewise Polynomials
48 Splines
49 Cubic Curves in 3D
50 Cubic Hermite Splines
51 Deriving Hermite Splines
52 Deriving Hermite Splines
53 Deriving Hermite Splines
54 The Cubic Hermite Spline Equation
55 Four Basis Functions for Hermite Splines
56 Piecing together Hermite Splines
57 Hermite Splines in Adobe Illustrator
58 Bezier s Idea! In graphics and CAD, we do not usually have derivative data! Bezier suggested using the same 4 data points as with the cubic interpolating curve to approximate the derivatives in the Hermite form
59 Bezier Splines
60 Approximating Derivatives p 1 located at u=1/3 p 1 p 2 p 2 located at u=2/3 p p0 p'(0) 1/ 3 1 p p2 p'(1) 1/ 3 3 slope p (0) slope p (1) p 0 u p 3
61 The Bezier Spline Matrix
62 Bezier Blending Functions
63 DeCasteljau Construction
64 Bezier Patches Using same data array P=[p ij ] as with interpolating form p( u, v) 3 3 = i= 0 j= 0 bi( u) b j ( v) p ij = u T M B P M T B v Patch lies in convex hull
65 Analysis! Although the Bezier form is much better than the interpolating form, we have the derivatives are not continuous at join points! Can we do better? Go to higher order Bezier More work Derivative continuity still only approximate Supported by OpenGL Apply different conditions Tricky without letting order increase
66 CatmullRom Splines
67 Constructing the CatmullRom Spline
68 CatmullRom Spline Matrix
69 Splines with More Continuity?
70 Comparison of Basic Cubic Splines
71 Natural Cubic Splines
72 BSplines
73 BSplines! Basis splines: use the data at p=[p i2 p i1 p i p i1 ] T to define curve only between p i1 and p i! Allows us to apply more continuity conditions to each segment! For cubics, we can have continuity of function, first and second derivatives at join points! Cost is 3 times as much work for curves Add one new point each time rather than three! For surfaces, we do 9 times as much work
74 BSpline Basis
75 Other Common Types of Splines
76 Generalizing Splines! We can extend to splines of any degree! Data and conditions to not have to given at equally spaced values (the knots) Nonuniform and uniform splines Can have repeated knots Can force spline to interpolate points! CoxdeBoor recursion gives method of evaluation
77 NURBS! Nonuniform Rational BSpline curves and surfaces add a fourth variable w to x,y,z Can interpret as weight to give more importance to some control data Can also interpret as moving to homogeneous coordinate! Requires a perspective division NURBS act correctly for perspective viewing! Quadrics are a special case of NURBS
78 How to Draw Spline Curves
79 Drawing Splines, continued
80 Summary
81 Project: Roller Coaster! use CatmullRom splines along with lighting and texture mapping to create a roller coaster simulation! runs in a firstperson view, allowing the user to ride the coaster in an immersive environment
82 Animation
Image Formation. Ed Angel Professor of Computer Science, Electrical and Computer Engineering, and Media Arts University of New Mexico
Image Formation Ed Angel Professor of Computer Science, Electrical and Computer Engineering, and Media Arts University of New Mexico 1 Objectives Fundamental imaging notions Physical basis for image formation
More informationIntroduction to Computer Graphics with WebGL
Introduction to Computer Graphics with WebGL Ed Angel Professor Emeritus of Computer Science Founding Director, Arts, Research, Technology and Science Laboratory University of New Mexico Image Formation
More informationPhysical Color. Color Theory  Center for Graphics and Geometric Computing, Technion 2
Color Theory Physical Color Visible energy  small portion of the electromagnetic spectrum Pure monochromatic colors are found at wavelengths between 380nm (violet) and 780nm (red) 380 780 Color Theory
More informationVisible Color. 700 (red) 580 (yellow) 520 (green)
Color Theory Physical Color Visible energy  small portion of the electromagnetic spectrum Pure monochromatic colors are found at wavelengths between 380nm (violet) and 780nm (red) 380 780 Color Theory
More information3D graphics, raster and colors CS312 Fall 2010
Computer Graphics 3D graphics, raster and colors CS312 Fall 2010 Shift in CG Application Markets 19892000 2000 1989 3D Graphics Object description 3D graphics model Visualization 2D projection that simulates
More informationLecture 1. Computer Graphics and Systems. Tuesday, January 15, 13
Lecture 1 Computer Graphics and Systems What is Computer Graphics? Image Formation Sun Object Figure from Ed Angel,D.Shreiner: Interactive Computer Graphics, 6 th Ed., 2012 Addison Wesley Computer Graphics
More informationINTRODUCTION. Slides modified from Angel book 6e
INTRODUCTION Slides modified from Angel book 6e Fall 2012 COSC4328/5327 Computer Graphics 2 Objectives Historical introduction to computer graphics Fundamental imaging notions Physical basis for image
More informationColor and Shading. Color. Shapiro and Stockman, Chapter 6. Color and Machine Vision. Color and Perception
Color and Shading Color Shapiro and Stockman, Chapter 6 Color is an important factor for for human perception for object and material identification, even time of day. Color perception depends upon both
More informationComputer Graphics. Curves and Surfaces. Hermite/Bezier Curves, (B)Splines, and NURBS. By Ulf Assarsson
Computer Graphics Curves and Surfaces Hermite/Bezier Curves, (B)Splines, and NURBS By Ulf Assarsson Most of the material is originally made by Edward Angel and is adapted to this course by Ulf Assarsson.
More informationThe Elements of Colour
Color science 1 The Elements of Colour Perceived light of different wavelengths is in approximately equal weights achromatic.
More informationCOMP3421. Global Lighting Part 2: Radiosity
COMP3421 Global Lighting Part 2: Radiosity Recap: Global Lighting The lighting equation we looked at earlier only handled direct lighting from sources: We added an ambient fudge term to account for all
More informationMain topics in the Chapter 2. Chapter 2. Digital Image Representation. Bitmaps digitization. Three Types of Digital Image Creation CS 3570
Main topics in the Chapter Chapter. Digital Image Representation CS 3570 Three main types of creating digital images Bitmapping, Vector graphics, Procedural modeling Frequency in digital image Discrete
More informationFall CSCI 420: Computer Graphics. 4.2 Splines. Hao Li.
Fall 2014 CSCI 420: Computer Graphics 4.2 Splines Hao Li http://cs420.haoli.com 1 Roller coaster Next programming assignment involves creating a 3D roller coaster animation We must model the 3D curve
More informationCurves and Surfaces 1
Curves and Surfaces 1 Representation of Curves & Surfaces Polygon Meshes Parametric Cubic Curves Parametric BiCubic Surfaces Quadric Surfaces Specialized Modeling Techniques 2 The Teapot 3 Representing
More informationIllumination and Shading
Illumination and Shading Light sources emit intensity: assigns intensity to each wavelength of light Humans perceive as a colour  navy blue, light green, etc. Exeriments show that there are distinct I
More informationSpectral Color and Radiometry
Spectral Color and Radiometry Louis Feng April 13, 2004 April 13, 2004 Realistic Image Synthesis (Spring 2004) 1 Topics Spectral Color Light and Color Spectrum Spectral Power Distribution Spectral Color
More informationIntro to Modeling Modeling in 3D
Intro to Modeling Modeling in 3D Polygon sets can approximate more complex shapes as discretized surfaces 2 1 2 3 Curve surfaces in 3D Sphere, ellipsoids, etc Curved Surfaces Modeling in 3D ) ( 2 2 2 2
More informationCS130 : Computer Graphics Lecture 2: Graphics Pipeline. Tamar Shinar Computer Science & Engineering UC Riverside
CS130 : Computer Graphics Lecture 2: Graphics Pipeline Tamar Shinar Computer Science & Engineering UC Riverside Raster Devices and Images Raster Devices  raster displays show images as a rectangular array
More informationCSE 167: Lecture #6: Color. Jürgen P. Schulze, Ph.D. University of California, San Diego Fall Quarter 2011
CSE 167: Introduction to Computer Graphics Lecture #6: Color Jürgen P. Schulze, Ph.D. University of California, San Diego Fall Quarter 2011 Announcements Homework project #3 due this Friday, October 14
More informationCSE 167: Lecture #7: Color and Shading. Jürgen P. Schulze, Ph.D. University of California, San Diego Fall Quarter 2011
CSE 167: Introduction to Computer Graphics Lecture #7: Color and Shading Jürgen P. Schulze, Ph.D. University of California, San Diego Fall Quarter 2011 Announcements Homework project #3 due this Friday,
More informationCurves and Surfaces Computer Graphics I Lecture 9
15462 Computer Graphics I Lecture 9 Curves and Surfaces Parametric Representations Cubic Polynomial Forms Hermite Curves Bezier Curves and Surfaces [Angel 10.110.6] February 19, 2002 Frank Pfenning Carnegie
More informationCHAPTER 3 COLOR MEASUREMENT USING CHROMATICITY DIAGRAM  SOFTWARE
49 CHAPTER 3 COLOR MEASUREMENT USING CHROMATICITY DIAGRAM  SOFTWARE 3.1 PREAMBLE Software has been developed following the CIE 1931 standard of Chromaticity Coordinates to convert the RGB data into its
More informationCOMP3421. Global Lighting Part 2: Radiosity
COMP3421 Global Lighting Part 2: Radiosity Recap: Global Lighting The lighting equation we looked at earlier only handled direct lighting from sources: We added an ambient fudge term to account for all
More informationAnimation & Rendering
7M836 Animation & Rendering Introduction, color, raster graphics, modeling, transformations Arjan Kok, Kees Huizing, Huub van de Wetering h.v.d.wetering@tue.nl 1 Purpose Understand 3D computer graphics
More informationCS452/552; EE465/505. Image Formation
CS452/552; EE465/505 Image Formation 11515 Outline! Image Formation! Introduction to WebGL, continued Draw a colored triangle using WebGL Read: Angel, Chapters 2 & 3 Homework #1 will be available on
More informationAn introduction to interpolation and splines
An introduction to interpolation and splines Kenneth H. Carpenter, EECE KSU November 22, 1999 revised November 20, 2001, April 24, 2002, April 14, 2004 1 Introduction Suppose one wishes to draw a curve
More informationCSE 167: Introduction to Computer Graphics Lecture #13: Curves. Jürgen P. Schulze, Ph.D. University of California, San Diego Fall Quarter 2017
CSE 167: Introduction to Computer Graphics Lecture #13: Curves Jürgen P. Schulze, Ph.D. University of California, San Diego Fall Quarter 2017 Announcements Project 4 due Monday Nov 27 at 2pm Next Tuesday:
More informationMultimedia Technology CHAPTER 4. Video and Animation
CHAPTER 4 Video and Animation  Both video and animation give us a sense of motion. They exploit some properties of human eye s ability of viewing pictures.  Motion video is the element of multimedia
More informationComputergrafik. Matthias Zwicker. Herbst 2010
Computergrafik Matthias Zwicker Universität Bern Herbst 2010 Today Curves NURBS Surfaces Parametric surfaces Bilinear patch Bicubic Bézier patch Advanced surface modeling Piecewise Bézier curves Each segment
More informationComputergrafik. Matthias Zwicker Universität Bern Herbst 2016
Computergrafik Matthias Zwicker Universität Bern Herbst 2016 Today Curves NURBS Surfaces Parametric surfaces Bilinear patch Bicubic Bézier patch Advanced surface modeling 2 Piecewise Bézier curves Each
More informationBezier Curves, BSplines, NURBS
Bezier Curves, BSplines, NURBS Example Application: Font Design and Display Curved objects are everywhere There is always need for: mathematical fidelity high precision artistic freedom and flexibility
More informationColor and Light. CSCI 4229/5229 Computer Graphics Summer 2008
Color and Light CSCI 4229/5229 Computer Graphics Summer 2008 Solar Spectrum Human Trichromatic Color Perception Are A and B the same? Color perception is relative Transmission,Absorption&Reflection Light
More informationLecture #2: Color and Linear Algebra pt.1
Lecture #2: Color and Linear Algebra pt.1 John McNelly, Alexander Haigh, Madeline Saviano, Scott Kazmierowicz, Cameron Van de Graaf Department of Computer Science Stanford University Stanford, CA 94305
More informationCOURSE DELIVERY PLAN  THEORY Page 1 of 6
COURSE DELIVERY PLAN  THEORY Page 1 of 6 Department of Department of Computer Science and Engineering B.E/B.Tech/M.E/M.Tech : Department of Computer Science and Engineering Regulation : 2013 Sub. Code
More informationImage Formation. CS418 Computer Graphics Eric Shaffer.
Image Formation CS418 Computer Graphics Eric Shaffer http://graphics.cs.illinois.edu/cs418/fa14 Some stuff about the class Grades probably on usual scale: 97 to 93: A 93 to 90: A 90 to 87: B+ 87 to 83:
More informationWhat is it? How does it work? How do we use it?
What is it? How does it work? How do we use it? Dual Nature http://www.youtube.com/watch?v=dfpeprq7ogc o Electromagnetic Waves display wave behavior o Created by oscillating electric and magnetic fields
More information3D Modeling techniques
3D Modeling techniques 0. Reconstruction From real data (not covered) 1. Procedural modeling Automatic modeling of a selfsimilar objects or scenes 2. Interactive modeling Provide tools to computer artists
More informationShape Representation Basic problem We make pictures of things How do we describe those things? Many of those things are shapes Other things include
Shape Representation Basic problem We make pictures of things How do we describe those things? Many of those things are shapes Other things include motion, behavior Graphics is a form of simulation and
More informationLecture 2 5 Aug 2004
TOPICS in IT: ADVANCED GRAPHICS (CS & SE 233.420) Lecture 2 5 Aug 2004 1 Topics Image Formation Electromagnetic spectrum Light Human Visual Image processing Color Programming in OpenGL Background Programming
More informationCSE 167: Introduction to Computer Graphics Lecture #11: Bezier Curves. Jürgen P. Schulze, Ph.D. University of California, San Diego Fall Quarter 2016
CSE 167: Introduction to Computer Graphics Lecture #11: Bezier Curves Jürgen P. Schulze, Ph.D. University of California, San Diego Fall Quarter 2016 Announcements Project 3 due tomorrow Midterm 2 next
More informationCurves & Surfaces. Last Time? Progressive Meshes. Selective Refinement. Adjacency Data Structures. Mesh Simplification. Mesh Simplification
Last Time? Adjacency Data Structures Curves & Surfaces Geometric & topologic information Dynamic allocation Efficiency of access Mesh Simplification edge collapse/vertex split geomorphs progressive transmission
More informationComputer Graphics and Visualization. Graphics Systems and Models
UNIT 1 Graphics Systems and Models 1.1 Applications of computer graphics: Display Of Information Design Simulation & Animation User Interfaces 1.2 Graphics systems A Graphics system has 5 main elements:
More informationMA 323 Geometric Modelling Course Notes: Day 21 Three Dimensional Bezier Curves, Projections and Rational Bezier Curves
MA 323 Geometric Modelling Course Notes: Day 21 Three Dimensional Bezier Curves, Projections and Rational Bezier Curves David L. Finn Over the next few days, we will be looking at extensions of Bezier
More informationAdvanced TextureMapping Curves and Curved Surfaces. PreLecture Business. Texture Modes. Texture Modes. Review quiz
Advanced TextureMapping Curves and Curved Surfaces Preecture Business loadtexture example midterm handed bac, code posted (still) get going on pp3! more on texturing review quiz CS148: Intro to CG Instructor:
More informationExtensions of OneDimensional Graylevel Nonlinear Image Processing Filters to ThreeDimensional Color Space
Extensions of OneDimensional Graylevel Nonlinear Image Processing Filters to ThreeDimensional Color Space Orlando HERNANDEZ and Richard KNOWLES Department Electrical and Computer Engineering, The College
More informationImage Analysis and Formation (Formation et Analyse d'images)
Image Analysis and Formation (Formation et Analyse d'images) James L. Crowley ENSIMAG 3  MMIS Option MIRV First Semester 2010/2011 Lesson 4 19 Oct 2010 Lesson Outline: 1 The Physics of Light...2 1.1 Photons
More informationA Data Flow Approach to Color Gamut Visualization
A Data Flow Approach to Color Gamut Visualization Gary W. Meyer and Chad A. Robertson Department of Computer and Information Science University of Oregon, Eugene, Oregon 97403 Abstract Software has been
More informationICC color management for print production
ICC color management for print production TAGA Annual Technical Conference 2002 W Craig Revie Principal Consultant Fuji Film Electronic Imaging Limited ICC Chair of the Graphic Arts Special Interest Group
More informationCIE L*a*b* color model
CIE L*a*b* color model To further strengthen the correlation between the color model and human perception, we apply the following nonlinear transformation: with where (X n,y n,z n ) are the tristimulus
More informationMathematical Tools in Computer Graphics with C# Implementations Table of Contents
Mathematical Tools in Computer Graphics with C# Implementations by Hardy Alexandre, WilliHans Steeb, World Scientific Publishing Company, Incorporated, 2008 Table of Contents List of Figures Notation
More informationWhen this experiment is performed, subjects find that they can always. test field. adjustable field
COLORIMETRY In photometry a lumen is a lumen, no matter what wavelength or wavelengths of light are involved. But it is that combination of wavelengths that produces the sensation of color, one of the
More informationCS681 Computational Colorimetry
9/14/17 CS681 Computational Colorimetry Min H. Kim KAIST School of Computing COLOR (3) 2 1 Color matching functions User can indeed succeed in obtaining a match for all visible wavelengths. So color space
More informationCurves and Surfaces 2
Curves and Surfaces 2 Computer Graphics Lecture 17 Taku Komura Today More about Bezier and Bsplines de Casteljau s algorithm BSpline : General form de Boor s algorithm Knot insertion NURBS Subdivision
More informationOutline. The de Casteljau Algorithm. Properties of Piecewise Linear Interpolations. Recall: Linear Interpolation
CS 430/585 Computer Graphics I Curve Drawing Algorithms Week 4, Lecture 8 David Breen, William Regli and Maxim Peysakhov Geometric and Intelligent Computing Laboratory Department of Computer Science Drexel
More informationArtistic Rendering of Functionbased Shape Models
Artistic Rendering of Functionbased Shape Models by Shunsuke Suzuki Faculty of Computer and Information Science Hosei University n00k1021@k.hosei.ac.jp Supervisor: Alexander Pasko March 2004 1 Abstract
More informationTWO APPROACHES IN SCANNERPRINTER CALIBRATION: COLORIMETRIC SPACEBASED VS. CLOSEDLOOP.
TWO APPROACHES I SCAERPRITER CALIBRATIO: COLORIMETRIC SPACEBASED VS. CLOSEDLOOP. V. Ostromoukhov, R.D. Hersch, C. Péraire, P. Emmel, I. Amidror Swiss Federal Institute of Technology (EPFL) CH15 Lausanne,
More informationCS GAME PROGRAMMING Question bank
CS6006  GAME PROGRAMMING Question bank Part A Unit I 1. List the different types of coordinate systems. 2. What is ray tracing? Mention some applications of ray tracing. 3. Discuss the stages involved
More informationVisual cues The human headway
Visual cues The human headway Overlapping objects Quantized scenes Lo sposalizio della Vergine Raffaello Sanzio Pinacoteca di Brera Perspective geometry Depth from shading Multipresence Depth from texture
More information2003 Steve Marschner 7 Light detection discrete approx. Cone Responses S,M,L cones have broadband spectral sensitivity This sum is very clearly a dot
2003 Steve Marschner Color science as linear algebra Last time: historical the actual experiments that lead to understanding color strictly based on visual observations Color Science CONTD. concrete but
More informationOrthogonal Projection Matrices. Angel and Shreiner: Interactive Computer Graphics 7E AddisonWesley 2015
Orthogonal Projection Matrices 1 Objectives Derive the projection matrices used for standard orthogonal projections Introduce oblique projections Introduce projection normalization 2 Normalization Rather
More informationCS770/870 Spring 2017 Curve Generation
CS770/870 Spring 2017 Curve Generation Primary resources used in preparing these notes: 1. Foley, van Dam, Feiner, Hughes, Phillips, Introduction to Computer Graphics, AddisonWesley, 1993. 2. Angel, Interactive
More informationCurves & Surfaces. MIT EECS 6.837, Durand and Cutler
Curves & Surfaces Schedule Sunday October 5 th, * 35 PM * Review Session for Quiz 1 Extra Office Hours on Monday Tuesday October 7 th : Quiz 1: In class 1 handwritten 8.5x11 sheet of notes allowed Wednesday
More informationFoundations of 3D Graphics Programming
Foundations of 3D Graphics Programming Jim X. Chen Edward J. Wegman Foundations of 3D Graphics Programming Using JOGL and Java3D With 139 Figures Jim X. Chen, PhD Computer Science Department George Mason
More informationCurves and Curved Surfaces. Adapted by FFL from CSE167: Computer Graphics Instructor: Ronen Barzel UCSD, Winter 2006
Curves and Curved Surfaces Adapted by FFL from CSE167: Computer Graphics Instructor: Ronen Barzel UCSD, Winter 2006 Outline for today Summary of Bézier curves Piecewisecubic curves, Bsplines Surface
More informationComputer graphics 2 Marks 1. Define Computer graphics.
Computer graphics 2 Marks 1. Define Computer graphics. Computer graphics remains one of the most existing and rapidly growing computer fields. Computer graphics may be defined as a pictorial representation
More informationAnnouncements. Written Assignment 2 out (due March 8) Computer Graphics
Announcements Written Assignment 2 out (due March 8) 1 Advanced Ray Tracing (Recursive) Ray Tracing Antialiasing Motion Blur Distribution Ray Tracing Ray Tracing and Radiosity Assumptions Simple shading
More informationColor Balancing Experimental Projection Displays
Color Balancing Experimental Projection Displays Maureen C. Stone StoneSoup Consulting, Los Altos, CA Abstract Experimental, tiled displays made of commodity projectors provide a relatively easy and cost
More informationCSE 167: Introduction to Computer Graphics Lecture #10: View Frustum Culling
CSE 167: Introduction to Computer Graphics Lecture #10: View Frustum Culling Jürgen P. Schulze, Ph.D. University of California, San Diego Fall Quarter 2015 Announcements Project 4 due tomorrow Project
More information3D Programming. 3D Programming Concepts. Outline. 3D Concepts. 3D Concepts  Coordinate Systems. 3D Concepts Displaying 3D Models
3D Programming Concepts Outline 3D Concepts Displaying 3D Models 3D Programming CS 4390 3D Computer 1 2 3D Concepts 3D Model is a 3D simulation of an object. Coordinate Systems 3D Models 3D Shapes 3D Concepts
More informationComputer Graphics and Visualization. What is computer graphics?
CSCI 120 Computer Graphics and Visualization Shiaofen Fang Department of Computer and Information Science Indiana University Purdue University Indianapolis What is computer graphics? Computer graphics
More informationPhotorealistic 3D Rendering for VW in Mobile Devices
Abstract University of Arkansas CSCE Department Advanced Virtual Worlds Spring 2013 Photorealistic 3D Rendering for VW in Mobile Devices Rafael Aroxa In the past few years, the demand for high performance
More informationNote to users of this presentation (this slide does not display during show)
ICC Colour Management Venue Presenter Organisation Date Note to users of this presentation (this slide does not display during show) Some content in this presentation is excerpted, with permission, from
More informationLets assume each object has a defined colour. Hence our illumination model is looks unrealistic.
Shading Models There are two main types of rendering that we cover, polygon rendering ray tracing Polygon rendering is used to apply illumination models to polygons, whereas ray tracing applies to arbitrary
More informationWednesday, 26 January 2005, 14:OO  17:OO h.
Delft University of Technology Faculty Electrical Engineering, Mathematics, and Computer Science Mekelweg 4, Delft TU Delft Examination for Course IN41 5 13D Computer Graphics and Virtual Reality Please
More informationColor. Phillip Otto Runge ( )
Color Phillip Otto Runge (17771810) Overview The nature of color Color processing in the human visual system Color spaces Adaptation and constancy White balance Uses of color in computer vision What is
More informationOptical Flow CS 637. Fuxin Li. With materials from Kristen Grauman, Richard Szeliski, S. Narasimhan, Deqing Sun
Optical Flow CS 637 Fuxin Li With materials from Kristen Grauman, Richard Szeliski, S. Narasimhan, Deqing Sun Motion and perceptual organization Sometimes, motion is the only cue Motion and perceptual
More informationDigital Images. Kyungim Baek. Department of Information and Computer Sciences. ICS 101 (November 1, 2016) Digital Images 1
Digital Images Kyungim Baek Department of Information and Computer Sciences ICS 101 (November 1, 2016) Digital Images 1 iclicker Question I know a lot about how digital images are represented, stored,
More informationPhotorealism: Ray Tracing
Photorealism: Ray Tracing Reading Assignment: Chapter 13 Local vs. Global Illumination Local Illumination depends on local object and light sources only Global Illumination at a point can depend on any
More informationA DATA FLOW APPROACH TO COLOR GAMUT VISUALIZATION
A DATA FLOW APPROACH TO COLOR GAMUT VISUALIZATION by CHAD ANDREW ROBERTSON A THESIS Presented to the Department of Computer and Information Science and the Graduate School of the University of Oregon in
More informationPS Geometric Modeling Homework Assignment Sheet I (Due 20Oct2017)
Homework Assignment Sheet I (Due 20Oct2017) Assignment 1 Let n N and A be a finite set of cardinality n = A. By definition, a permutation of A is a bijective function from A to A. Prove that there exist
More informationProperties of Blending Functions
Chapter 5 Properties of Blending Functions We have just studied how the Bernstein polynomials serve very nicely as blending functions. We have noted that a degree n Bézier curve always begins at P 0 and
More informationSection 2 Flat Mirrors. Distinguish between specular and diffuse reflection of light. Apply the law of reflection for flat mirrors.
Section 2 Flat Mirrors Objectives Distinguish between specular and diffuse reflection of light. Apply the law of reflection for flat mirrors. Describe the nature of images formed by flat mirrors. Section
More informationOverview CS Plans for this semester. References. CS 4600 Fall Prerequisites
Overview CS 4600 What is CS 4600? What should know (pre reqs)? What will you get out of this course? Chuck Hansen Website: www.eng.utah.edu/~cs4600 Thanks to Ed Angel and Jeff Parker for slides and materials
More informationShading Languages. Seminar Computer Graphics. Markus Kummerer
Shading Languages Markus Kummerer ABSTRACT Shading Languages provide a highly flexible approach for creating visual structures in computer imagery. The RenderMan Interface provides an API for scene description,
More informationShadow Algorithms. CSE 781 Winter HanWei Shen
Shadow Algorithms CSE 781 Winter 2010 HanWei Shen Why Shadows? Makes 3D Graphics more believable Provides additional cues for the shapes and relative positions of objects in 3D What is shadow? Shadow:
More informationECE 600, Dr. Farag, Summer 09
ECE 6 Summer29 Course Supplements. Lecture 4 Curves and Surfaces Aly A. Farag University of Louisville Acknowledgements: Help with these slides were provided by Shireen Elhabian A smile is a curve that
More informationLECTURE #6. Geometric Modelling for Engineering Applications. Geometric modeling for engineering applications
LECTURE #6 Geometric modeling for engineering applications Geometric Modelling for Engineering Applications Introduction to modeling Geometric modeling Curve representation Hermite curve Bezier curve Bspline
More informationHIGHLY PARALLEL COMPUTING IN PHYSICSBASED RENDERING OpenCL Raytracing Based. Thibaut PRADOS OPTIS RealTime & Virtual Reality Manager
HIGHLY PARALLEL COMPUTING IN PHYSICSBASED RENDERING OpenCL Raytracing Based Thibaut PRADOS OPTIS RealTime & Virtual Reality Manager INTRODUCTION WHO WE ARE 3 Highly Parallel Computing in Physicsbased
More informationOverview: Ray Tracing & The Perspective Projection Pipeline
Overview: Ray Tracing & The Perspective Projection Pipeline Lecture #2 Thursday, August 28 2014 About this Lecture! This is an overview.! Think of it as a quick tour moving fast.! Some parts, e.g. math,
More informationColor Image Enhancement Using Optimal Linear Transform with Hue Preserving and Saturation Scaling
International Journal of Intelligent Engineering & Systems http://www.inass.org/ Color Image Enhancement Using Optimal Linear Transform with Hue Preserving and Saturation Scaling Xiaohua Zhang 1, Yuelan
More informationBezier Curves. An Introduction. Detlef Reimers
Bezier Curves An Introduction Detlef Reimers detlefreimers@gmx.de http://detlefreimers.de September 1, 2011 Chapter 1 Bezier Curve Basics 1.1 Linear Interpolation This section will give you a basic introduction
More informationIntroduction to Geometry. Computer Graphics CMU /15662
Introduction to Geometry Computer Graphics CMU 15462/15662 Assignment 2: 3D Modeling You will be able to create your own models (This mesh was created in Scotty3D in about 5 minutes... you can do much
More informationPolygon Meshes and Implicit Surfaces
CSCI 420 Computer Graphics Lecture 9 and Constructive Solid Geometry [Angel Ch. 10] Jernej Barbic University of Southern California Modeling Complex Shapes An equation for a sphere is possible, but how
More informationCOMPUTER AIDED GEOMETRIC DESIGN. Thomas W. Sederberg
COMPUTER AIDED GEOMETRIC DESIGN Thomas W. Sederberg January 31, 2011 ii T. W. Sederberg iii Preface This semester is the 24 th time I have taught a course at Brigham Young University titled, Computer Aided
More informationSo far, we have considered only local models of illumination; they only account for incident light coming directly from the light sources.
11 11.1 Basics So far, we have considered only local models of illumination; they only account for incident light coming directly from the light sources. Global models include incident light that arrives
More informationKnot Insertion and Reparametrization of Interval Bspline Curves
International Journal of Video&Image Processing and Network Security IJVIPNSIJENS Vol:14 No:05 1 Knot Insertion and Reparametrization of Interval Bspline Curves O. Ismail, Senior Member, IEEE Abstract
More informationDirect Rendering of Trimmed NURBS Surfaces
Direct Rendering of Trimmed NURBS Surfaces Hardware Graphics Pipeline 2/ 81 Hardware Graphics Pipeline GPU Video Memory CPU Vertex Processor Raster Unit Fragment Processor Render Target Screen Extended
More informationScanline Rendering 2 1/42
Scanline Rendering 2 1/42 Review 1. Set up a Camera the viewing frustum has near and far clipping planes 2. Create some Geometry made out of triangles 3. Place the geometry in the scene using Transforms
More informationComputer Graphics. Si Lu. Fall uter_graphics.htm 11/27/2017
Computer Graphics Si Lu Fall 2017 http://web.cecs.pdx.edu/~lusi/cs447/cs447_547_comp uter_graphics.htm 11/27/2017 Last time o Ray tracing 2 Today o Animation o Final Exam: 14:0015:30, Novermber 29, 2017
More informationVisual Design and Imaging Alignment
Visual Design and Imaging Alignment This document contains information about four CareerTechnical Articulation Numbers (CTANs) for the Visual Design and Imaging Alignment CareerTechnical Assurance Guide
More information