skip chap. 8 for now Chap. 9 Color (continued) Lecture 19 Tuesday, October 26

Size: px
Start display at page:

Download "skip chap. 8 for now Chap. 9 Color (continued) Lecture 19 Tuesday, October 26"

Transcription

1 skip chap. 8 for now Chap. 9 Color (continued) Lecture 19 Tuesday, October 26 Next time: Chapter 10, start reading. Nov. 2: exam review Nov. 4: exam II There are computer problems with clicker registration. Be patient. 1 Ch. 9 - Color We are here Spectral and non-spectral colors Intensity distribution curve Intensity, hue, saturation Additive primaries: R, G. B. Subtractive primaries: C, M, Y Hair, skin, and eye color CIE diagram Lighting, painting and printing Start Chapter 10, color perception. 2

2 CIE diagram (International Commission on Illumination) This is a color triangle with Green at the top, Blue at lower left, Red at (lower) right x,y positions on the color triangle represent all the colors that can be reproduced by adding red, green and blue. Limitation: darkness is missing. To be complete you must also specify lightness or brightness. 3 White: X = 1/3 Y = 1/3 Less saturated colors are near the center Spectral color wavelengths are at the left and right edges Non spectral colors are at this edge 4

3 Projection (additive) TV systems can only reproduce colors inside the triangle between the 3 colors of the sources (dots). 5 Comparison of old TV phosphors with LEDs (light emitting diodes) 6

4 Properties of the CIE diagram The spectral colors are on the left and right edges Equal mixing of two spectral colors on the edge makes the color half way between these two colors (on the line joining the two colors.) Where is magenta on the diagram? It is half way across the bottom, which is an equal mixture of red and blue. Where is cyan? What s great about this diagram: two numbers, x and y, can be used to describe a color. What s missing from the C.I.E. diagram? Because the colors are adjusted to add to 100%, dark colors (that total less than 100%) aren t represented, for example, black and brown. 7 Alternate diagram: Munsell s color tree: Hue, value and chroma an alternate way to indicate color that includes brightness Compare to: 8

5 Ink transmission curves Magenta = white green 100% 400 nm 500 nm 600 nm 700 nm 9 Ink transmission curves Cyan = white red 100% 400 nm 500 nm 600 nm 700 nm 10

6 Ink transmission curves Yellow ink (unsaturated) = white blue (contains green, yellow, orange and red) 100% 400 nm 500 nm 600 nm 700 nm 11 Additive and subtractive color mixing Why does one figure have a black interior and the other is white? 12

7 Ch. 9 - Color We are here Spectral and non-spectral colors Intensity distribution curve Intensity, hue, saturation Additive primaries: R, G. B. Subtractive primaries: C, M, Y Hair, skin, and eye color CIE diagram Lighting, painting and printing 13 Methods of adding colors 1. Addition of illumination: stage lighting and 3-color TV projector. Projected colors overlap. 2. Partitive mixing: closely spaced dots of colors. TV screens, laptop screens, pointillist paintings, tight textile weaves, some printing 3. Time mixing: a rotating color wheel. It s hard to find examples. 4. Binocular mixing: different color to each eye. The colors "blend" in the brain. 14

8 Partitive mixing is placing colors next to one another so that they are merged in the eye. Examples: Pointillist painting LCD screens Old TV screens (CRT) Plasma TVs Detail from Circus Sideshow (or Parade de Cirque) (1889) showing pointillism Georges Seurat 15 Georges Seurat, Sunday Afternoon on the Island of La Grande Jatte, , The Art Institute of Chicago. 16

9 Sources of light, color balance Color balance important for movies and stage lighting. White light should contain equal amounts R, G and B but often does not. Examples of odd (unbalanced) lighting: Candles and campfires contain an excess of red. So do sunsets and tungsten bulbs. Some street lamps (low pressure sodium, for example) contain only a few wavelengths. All other colors are missing. When red is missing, red lipstick looks black. Demo: blue light with red, white, and blue papers 17 Color temperature The temperature of light bulb determines the relative amount of red. Cooler bulbs have more red than hotter bulbs. A lamp can be characterized by its temperature Sun, 5000 K (has a lot of blue) Photoflood lamp, 3200 K, an approximation of sunlight Tungsten lamp, 2850 K, looks orange, less blue. Candle, 1800 K, distinctly red, almost no blue. Color film is balanced for daylight. Photos made by candlelight or ordinary tungsten lamps will look unnaturally red. Demo: blue and red filter with dimmed bulb 18

10 Ch. 9 - Color Spectral and non-spectral colors Intensity distribution curve Intensity, hue, saturation Additive primaries: R, G. B. Subtractive primaries: C, M, Y Hair, skin, and eye color CIE diagram Lighting, painting and printing We are here 19 Printing Ink jet printers use four inks: cyan, magenta, yellow, and black. These are often called CMYK printers, with K for black. Ink on the paper acts as a filter for light reflected from paper. Combinations of C, M, and Y can make all colors by filtration. Black is needed for darker blacks. High brightness paper is needed for good pictures. Six color printing adds additional inks to CMYK. Some use red and blue, others use light cyan and light magenta. Canon has an 11 ink printer. Watercolors work the same way. Putting on more results in more light being absorbed, so a brighter blue requires less watercolor and a darker one more. 20

11 Recall that inks act like filters A colored filter subtracts certain colors by absorption and transmits the rest = Incident white light Magenta filter subtracts green Cyan filter subtracts red Only blue gets through Halftone printing Halftones (black and white): The printing plate is covered with dots of different size with the bigger dots putting more ink than the smaller dots. Halftones (color) There is a different halftone printing plate for each of the subtractive primaries. High quality color printing (National Geographic, art books) use more than four inks. Print resolution is measured in dots per inch. More dots/inch = more detail. Typical inkjet: 600 dots per inch but 1200 to 4800 dots per inch (dpi) is possible 22

12 Halftone printing black and white Size of dots determines amount of black ink. Newspapers had 85 lines of dots per inch. Wikipedia Magnified view First half tone Halftone printing - color Where would I see this? Sunday comics. 24

13 Halftone printing - color Cyan = -red Magenta = -green Yellow = -blue This is the final printed product of adding the 4 above images. Magazines use this method. Wikipedia 25 Zoom in on a color half tone. 26

14 End - Ch. 9 - Color Spectral and non-spectral colors Intensity distribution curve Intensity, hue, saturation Additive primaries: R, G. B. Subtractive primaries: C, M, Y Hair, skin, and eye color CIE diagram Lighting, painting and printing We are here 27 Paint Paints: consist of pigment particles in a liquid vehicle. The vehicle may dry to a glossy or matte finish. The vehicle may be clear or it may contain dye. Dye is colored at the molecular level, no solid particles. Pigment flakes may be partially transparent and work by selective absorption or they may be opaque and work by selective reflection. The size of the particle makes a difference, with smaller particles transmitting more and absorbing less. Paints appear different (often brighter) when wet because a wet surface is glossy. 28

15 Surfaces, glossy and matte Photographs can have a glossy or matte finish and so can house paint. Paint can also be semi-gloss (looks frosted ). Glossy surfaces are smooth and part of the light is reflected specularly (like from a mirror) and part is reflected diffusely. Glossy surfaces look brighter. Wet surfaces tend to be glossy, so all paints are glossy when they go on and may become matte as they dry. 29 Chapter 10: Color perception We are here Trichromacy Metamers Psychological primaries Channels Color deficiency Animal vision Temporal processing 30

16 Trichromacy You have 3 kinds of color receptors (cones) Wavelengths: Short Intermediate Long We know this because we can find the wavelengths absorbed by the cones. Fig in textbook. 31 Metamers (again) Yellow (600) looks like red (650) + green (550) No mixture will look like blue or red. 32

17 Why blue+yellow looks white S+I+L stimulated is the same stimulation as from white light 33 How colors are perceived Blue excites S receptors Cyan excites S + I Green excites I mostly Yellow excites I + L Orange excites I + L Red excites L 34

18 Sensitivity of cones 35

Take a break: Watch some stop-motion animation Music: Grindin

Take a break: Watch some stop-motion animation Music: Grindin Take a break: Watch some stop-motion animation Music: Grindin http://vimeo.com/9625370 1 skip chap. 8 for now Chap. 9 Color (continued) Lecture 18 Thursday, March 11 Next week: Chapter 10, start reading.

More information

Physics 1230: Light and Color. If you do not have a telescope, please come get the parts on front table. Useful for Written_HW12.

Physics 1230: Light and Color. If you do not have a telescope, please come get the parts on front table. Useful for Written_HW12. Physics 1230: Light and Color Chuck Rogers, Charles.Rogers@colorado.edu Ryan Henley, Valyria McFarland, Peter Siegfried physicscourses.colorado.edu/phys1230 If you do not have a telescope, please come

More information

excite the cones in the same way.

excite the cones in the same way. Humans have 3 kinds of cones Color vision Edward H. Adelson 9.35 Trichromacy To specify a light s spectrum requires an infinite set of numbers. Each cone gives a single number (univariance) when stimulated

More information

Color Mixing. Color Systems and Additive and Subtractive Colors. MODIFIED FROM Dr. Patricia Hill, Millersville University

Color Mixing. Color Systems and Additive and Subtractive Colors. MODIFIED FROM Dr. Patricia Hill, Millersville University Color Mixing Color Systems and Additive and Subtractive Colors MODIFIED FROM Dr. Patricia Hill, Millersville University Describing Color Color Attributes Hue (color) Brightness Saturation or Purity corresponds

More information

Test 1: Example #2. Paul Avery PHY 3400 Feb. 15, Note: * indicates the correct answer.

Test 1: Example #2. Paul Avery PHY 3400 Feb. 15, Note: * indicates the correct answer. Test 1: Example #2 Paul Avery PHY 3400 Feb. 15, 1999 Note: * indicates the correct answer. 1. A red shirt illuminated with yellow light will appear (a) orange (b) green (c) blue (d) yellow * (e) red 2.

More information

Color Reproduction. Chapter 6

Color Reproduction. Chapter 6 Chapter 6 Color Reproduction Take a digital camera and click a picture of a scene. This is the color reproduction of the original scene. The success of a color reproduction lies in how close the reproduced

More information

What is Color? Chapter 9: Color. Color Mixtures. Color Mixtures 10/29/2012. What is color? Color vocabulary

What is Color? Chapter 9: Color. Color Mixtures. Color Mixtures 10/29/2012. What is color? Color vocabulary What is color? Color vocabulary Chapter 9: Color Color mixtures Intensity-distribution curves Specifying colors Hue, saturation and brightness Color trees RGB color specification Chromaticity What is Color?

More information

Multimedia Systems and Technologies

Multimedia Systems and Technologies Multimedia Systems and Technologies Faculty of Engineering Master s s degree in Computer Engineering Marco Porta Computer Vision & Multimedia Lab Dipartimento di Ingegneria Industriale e dell Informazione

More information

Multimedia Systems Color Space Mahdi Amiri March 2012 Sharif University of Technology

Multimedia Systems Color Space Mahdi Amiri March 2012 Sharif University of Technology Course Presentation Multimedia Systems Color Space Mahdi Amiri March 2012 Sharif University of Technology Physics of Color Light Light or visible light is the portion of electromagnetic radiation that

More information

Color & Graphics. Color & Vision. The complete display system is: We'll talk about: Model Frame Buffer Screen Eye Brain

Color & Graphics. Color & Vision. The complete display system is: We'll talk about: Model Frame Buffer Screen Eye Brain Color & Graphics The complete display system is: Model Frame Buffer Screen Eye Brain Color & Vision We'll talk about: Light Visions Psychophysics, Colorimetry Color Perceptually based models Hardware models

More information

Digital Images. CCST9015 Oct 13, 2010 Hayden Kwok-Hay So

Digital Images. CCST9015 Oct 13, 2010 Hayden Kwok-Hay So Digital Images CCST9015 Oct 13, 2010 Hayden Kwok-Hay So 1983 Oct 13, 2010 2006 Digital Images - CCST9015 - H. So 2 Demystifying Digital Images Representation Hardware Processing 3 Representing Images R

More information

The Principles of Chromatics

The Principles of Chromatics The Principles of Chromatics 03/20/07 2 Light Electromagnetic radiation, that produces a sight perception when being hit directly in the eye The wavelength of visible light is 400-700 nm 1 03/20/07 3 Visible

More information

Form 4: Integrated Science Notes TOPIC NATURAL AND ARTIFICIAL LIGHTING

Form 4: Integrated Science Notes TOPIC NATURAL AND ARTIFICIAL LIGHTING Form 4: Integrated Science Notes TOPIC NATURAL AND ARTIFICIAL LIGHTING OBJECTIVES: 1. Define natural and artificial lighting. 2. Use of fluorescent and filament lamps. 3. Investigation of white light and

More information

Color vision and representation

Color vision and representation Color vision and representation S M L 0.0 0.44 0.52 Mark Rzchowski Physics Department 1 Eye perceives different wavelengths as different colors. Sensitive only to 400nm - 700 nm range Narrow piece of the

More information

Color Image Processing. Gonzales & Woods: Chapter 6

Color Image Processing. Gonzales & Woods: Chapter 6 Color Image Processing Gonzales & Woods: Chapter 6 Objectives What are the most important concepts and terms related to color perception? What are the main color models used to represent and quantify color?

More information

Color theory Quick guide for graphic artists

Color theory Quick guide for graphic artists Quick guide for graphic artists We can talk about color using two kinds of terminology: Color generation systems. Color harmony system. Graphic artists and photographers certainly have to understand color

More information

Chapter 9: Color. What is Color? Wavelength is a property of an electromagnetic wave in the frequency range we call light

Chapter 9: Color. What is Color? Wavelength is a property of an electromagnetic wave in the frequency range we call light Chapter 9: Color What is color? Color mixtures Intensity-distribution curves Additive Mixing Partitive Mixing Specifying colors RGB Color Chromaticity What is Color? Wavelength is a property of an electromagnetic

More information

Comparing Sound and Light. Light and Color. More complicated light. Seeing colors. Rods and cones

Comparing Sound and Light. Light and Color. More complicated light. Seeing colors. Rods and cones Light and Color Eye perceives EM radiation of different wavelengths as different colors. Sensitive only to the range 4nm - 7 nm This is a narrow piece of the entire electromagnetic spectrum. Comparing

More information

Match the correct description with the correct term. Write the letter in the space provided.

Match the correct description with the correct term. Write the letter in the space provided. Skills Worksheet Directed Reading A Section: Interactions of Light with Matter REFLECTION Write the letter of the correct answer in the space provided. 1. What happens when light travels through a material

More information

Colour. Cunliffe & Elliott, Chapter 8 Chapman & Chapman, Digital Multimedia, Chapter 5. Autumn 2016 University of Stirling

Colour. Cunliffe & Elliott, Chapter 8 Chapman & Chapman, Digital Multimedia, Chapter 5. Autumn 2016 University of Stirling CSCU9N5: Multimedia and HCI 1 Colour What is colour? Human-centric view of colour Computer-centric view of colour Colour models Monitor production of colour Accurate colour reproduction Cunliffe & Elliott,

More information

Visual Imaging and the Electronic Age Color Science

Visual Imaging and the Electronic Age Color Science Visual Imaging and the Electronic Age Color Science Grassman s Experiments & Trichromacy Lecture #5 September 5, 2017 Prof. Donald P. Greenberg Light as Rays Light as Waves Light as Photons What is Color

More information

Colour. Why/How do we perceive colours? Electromagnetic Spectrum (1: visible is very small part 2: not all colours are present in the rainbow!

Colour. Why/How do we perceive colours? Electromagnetic Spectrum (1: visible is very small part 2: not all colours are present in the rainbow! Colour What is colour? Human-centric view of colour Computer-centric view of colour Colour models Monitor production of colour Accurate colour reproduction Colour Lecture (2 lectures)! Richardson, Chapter

More information

Mahdi Amiri. March Sharif University of Technology

Mahdi Amiri. March Sharif University of Technology Course Presentation Multimedia Systems Color Space Mahdi Amiri March 2014 Sharif University of Technology The wavelength λ of a sinusoidal waveform traveling at constant speed ν is given by Physics of

More information

Image and video processing (EBU723U) Colour Images. Dr. Yi-Zhe Song

Image and video processing (EBU723U) Colour Images. Dr. Yi-Zhe Song Image and video processing () Colour Images Dr. Yi-Zhe Song yizhe.song@qmul.ac.uk Today s agenda Colour spaces Colour images PGM/PPM images Today s agenda Colour spaces Colour images PGM/PPM images History

More information

Colour. Electromagnetic Spectrum (1: visible is very small part 2: not all colours are present in the rainbow!) Colour Lecture!

Colour. Electromagnetic Spectrum (1: visible is very small part 2: not all colours are present in the rainbow!) Colour Lecture! Colour Lecture! ITNP80: Multimedia 1 Colour What is colour? Human-centric view of colour Computer-centric view of colour Colour models Monitor production of colour Accurate colour reproduction Richardson,

More information

Understand brightness, intensity, eye characteristics, and gamma correction, halftone technology, Understand general usage of color

Understand brightness, intensity, eye characteristics, and gamma correction, halftone technology, Understand general usage of color Understand brightness, intensity, eye characteristics, and gamma correction, halftone technology, Understand general usage of color 1 ACHROMATIC LIGHT (Grayscale) Quantity of light physics sense of energy

More information

Reading for Color. Vision/Color. RGB Color. Vision/Color. University of British Columbia CPSC 314 Computer Graphics Jan-Apr 2013.

Reading for Color. Vision/Color. RGB Color. Vision/Color. University of British Columbia CPSC 314 Computer Graphics Jan-Apr 2013. University of British Columbia CPSC 314 Computer Graphics Jan-Apr 2013 Tamara Munzner Vision/Color Reading for Color RB Chap Color FCG Sections 3.2-3.3 FCG Chap 20 Color FCG Chap 21.2.2 Visual Perception

More information

Additive. Subtractive

Additive. Subtractive Physics 106 Additive Subtractive Subtractive Mixing Rules: Mixing Cyan + Magenta, one gets Blue Mixing Cyan + Yellow, one gets Green Mixing Magenta + Yellow, one gets Red Mixing any two of the Blue, Red,

More information

Slide 1. Slide 2. Slide 3. Light and Colour. Sir Isaac Newton The Founder of Colour Science

Slide 1. Slide 2. Slide 3. Light and Colour. Sir Isaac Newton The Founder of Colour Science Slide 1 the Rays to speak properly are not coloured. In them there is nothing else than a certain Power and Disposition to stir up a Sensation of this or that Colour Sir Isaac Newton (1730) Slide 2 Light

More information

Conceptual Physics 11 th Edition

Conceptual Physics 11 th Edition Conceptual Physics 11 th Edition Chapter 27: COLOR This lecture will help you understand: Color in Our World Selective Reflection Selective Transmission Mixing Colored Light Mixing Colored Pigments Why

More information

University of British Columbia CPSC 314 Computer Graphics Jan-Apr Tamara Munzner. Color.

University of British Columbia CPSC 314 Computer Graphics Jan-Apr Tamara Munzner. Color. University of British Columbia CPSC 314 Computer Graphics Jan-Apr 2016 Tamara Munzner Color http://www.ugrad.cs.ubc.ca/~cs314/vjan2016 Vision/Color 2 RGB Color triple (r, g, b) represents colors with amount

More information

Lecture 30 Chapter 26 The Human Eye & Visual Perception. Chapter 27 Color

Lecture 30 Chapter 26 The Human Eye & Visual Perception. Chapter 27 Color Lecture 30 Chapter 26 The Human Eye & Visual Perception Chapter 27 Color 4-Nov-10 The Eye As light enters the eye, it moves through the transparent cover, the cornea, which does about 70% of the necessary

More information

COLOR and the human response to light

COLOR and the human response to light COLOR and the human response to light Contents Introduction: The nature of light The physiology of human vision Color Spaces: Linear Artistic View Standard Distances between colors Color in the TV 2 How

More information

Psy 280 Fall 2000: Color Vision (Part 1) Oct 23, Announcements

Psy 280 Fall 2000: Color Vision (Part 1) Oct 23, Announcements Announcements 1. This week's topic will be COLOR VISION. DEPTH PERCEPTION will be covered next week. 2. All slides (and my notes for each slide) will be posted on the class web page at the end of the week.

More information

Thursday, May 19, 16. Color Theory

Thursday, May 19, 16. Color Theory Color Theory Which colours is white light made of? Did you know?! Your eyes have only 3 types of cells that can recognize millions of colours.! When you observe a colour, it is because different combinations

More information

Light and Colour. Light as part of the EM spectrum. Light as part of the EM spectrum

Light and Colour. Light as part of the EM spectrum. Light as part of the EM spectrum Light and Colour Prof. Grega Bizjak, PhD Laboratory of Lighting and Photometry Faculty of Electrical Engineering University of Ljubljana Light as part of the EM spectrum Visible light can be seen as part

More information

Color and Color Model. Chap. 12 Intro. to Computer Graphics, Spring 2009, Y. G. Shin

Color and Color Model. Chap. 12 Intro. to Computer Graphics, Spring 2009, Y. G. Shin Color and Color Model Chap. 12 Intro. to Computer Graphics, Spring 2009, Y. G. Shin Color Interpretation of color is a psychophysiology problem We could not fully understand the mechanism Physical characteristics

More information

COLOR. and the human response to light

COLOR. and the human response to light COLOR and the human response to light Contents Introduction: The nature of light The physiology of human vision Color Spaces: Linear Artistic View Standard Distances between colors Color in the TV 2 Amazing

More information

H10: Description of Colour

H10: Description of Colour page 1 of 7 H10: Description of Colour Appearance of objects and materials Appearance attributes can be split into primary and secondary parts, as shown in Table 1. Table 1: The attributes of the appearance

More information

Computer Graphics Si Lu Fall /27/2016

Computer Graphics Si Lu Fall /27/2016 Computer Graphics Si Lu Fall 2017 09/27/2016 Announcement Class mailing list https://groups.google.com/d/forum/cs447-fall-2016 2 Demo Time The Making of Hallelujah with Lytro Immerge https://vimeo.com/213266879

More information

Introduction. The Spectral Basis for Color

Introduction. The Spectral Basis for Color Introduction Color is an extremely important part of most visualizations. Choosing good colors for your visualizations involves understanding their properties and the perceptual characteristics of human

More information

Digital Image Processing

Digital Image Processing Digital Image Processing 6. Color Image Processing Computer Engineering, Sejong University Category of Color Processing Algorithm Full-color processing Using Full color sensor, it can obtain the image

More information

Chapter 16 Light Waves and Color

Chapter 16 Light Waves and Color Chapter 16 Light Waves and Color Lecture PowerPoint Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. What causes color? What causes reflection? What causes color?

More information

Interactive Computer Graphics

Interactive Computer Graphics Interactive Computer Graphics Lecture 4: Colour Graphics Lecture 4: Slide 1 Ways of looking at colour 1. Physics 2. Human visual receptors 3. Subjective assessment Graphics Lecture 4: Slide 2 The physics

More information

Light, Color, Spectra 05/30/2006. Lecture 17 1

Light, Color, Spectra 05/30/2006. Lecture 17 1 What do we see? Light Our eyes can t t detect intrinsic light from objects (mostly infrared), unless they get red hot The light we see is from the sun or from artificial light When we see objects, we see

More information

Printing Technology. Lecture 14 October 8, 2015 Imaging in the Electronic Age Donald P. Greenberg

Printing Technology. Lecture 14 October 8, 2015 Imaging in the Electronic Age Donald P. Greenberg Printing Technology Lecture 14 October 8, 2015 Imaging in the Electronic Age Donald P. Greenberg Color Additive Color Subtractive Color Additive & Subtractive Color Spaces Subtractive Reflection Processes

More information

Conceptual Physics Fundamentals

Conceptual Physics Fundamentals Conceptual Physics Fundamentals Chapter 13: LIGHT WAVES This lecture will help you understand: Electromagnetic Spectrum Transparent and Opaque Materials Color Why the Sky is Blue, Sunsets are Red, and

More information

Chapter Objectives. Color Management. Color Management. Chapter Objectives 1/27/12. Beyond Design

Chapter Objectives. Color Management. Color Management. Chapter Objectives 1/27/12. Beyond Design 1/27/12 Copyright 2009 Fairchild Books All rights reserved. No part of this presentation covered by the copyright hereon may be reproduced or used in any form or by any means graphic, electronic, or mechanical,

More information

A Colorful Lab in a Bag

A Colorful Lab in a Bag A Colorful Lab in a Bag In this lab you will explore color and color mixing. You will investigate the white light spectrum and examine ways in which color can be combined. One process of mixing color,

More information

28 Color. The colors of the objects depend on the color of the light that illuminates them.

28 Color. The colors of the objects depend on the color of the light that illuminates them. The colors of the objects depend on the color of the light that illuminates them. Color is in the eye of the beholder and is provoked by the frequencies of light emitted or reflected by things. We see

More information

Raster Graphics. Overview קורס גרפיקה ממוחשבת 2008 סמסטר ב' What is an image? What is an image? Image Acquisition. Image display 5/19/2008.

Raster Graphics. Overview קורס גרפיקה ממוחשבת 2008 סמסטר ב' What is an image? What is an image? Image Acquisition. Image display 5/19/2008. Overview Images What is an image? How are images displayed? Color models How do we perceive colors? How can we describe and represent colors? קורס גרפיקה ממוחשבת 2008 סמסטר ב' Raster Graphics 1 חלק מהשקפים

More information

קורס גרפיקה ממוחשבת 2008 סמסטר ב' Raster Graphics 1 חלק מהשקפים מעובדים משקפים של פרדו דוראנד, טומס פנקהאוסר ודניאל כהן-אור

קורס גרפיקה ממוחשבת 2008 סמסטר ב' Raster Graphics 1 חלק מהשקפים מעובדים משקפים של פרדו דוראנד, טומס פנקהאוסר ודניאל כהן-אור קורס גרפיקה ממוחשבת 2008 סמסטר ב' Raster Graphics 1 חלק מהשקפים מעובדים משקפים של פרדו דוראנד, טומס פנקהאוסר ודניאל כהן-אור Images What is an image? How are images displayed? Color models Overview How

More information

Dr. Shahanawaj Ahamad. Dr. S.Ahamad, SWE-423, Unit-06

Dr. Shahanawaj Ahamad. Dr. S.Ahamad, SWE-423, Unit-06 Dr. Shahanawaj Ahamad 1 Outline: Basic concepts underlying Images Popular Image File formats Human perception of color Various Color Models in use and the idea behind them 2 Pixels -- picture elements

More information

Additive Color Synthesis

Additive Color Synthesis Color Systems Defining Colors for Digital Image Processing Various models exist that attempt to describe color numerically. An ideal model should be able to record all theoretically visible colors in the

More information

Images and Colour COSC342. Lecture 2 2 March 2015

Images and Colour COSC342. Lecture 2 2 March 2015 Images and Colour COSC342 Lecture 2 2 March 2015 In this Lecture Images and image formats Digital images in the computer Image compression and formats Colour representation Colour perception Colour spaces

More information

Light. intensity wavelength. Light is electromagnetic waves Laser is light that contains only a narrow spectrum of frequencies

Light. intensity wavelength. Light is electromagnetic waves Laser is light that contains only a narrow spectrum of frequencies Image formation World, image, eye Light Light is electromagnetic waves Laser is light that contains only a narrow spectrum of frequencies intensity wavelength Visible light is light with wavelength from

More information

Digital Image Processing COSC 6380/4393. Lecture 20 Oct 25 th, 2018 Pranav Mantini

Digital Image Processing COSC 6380/4393. Lecture 20 Oct 25 th, 2018 Pranav Mantini Digital Image Processing COSC 6380/4393 Lecture 20 Oct 25 th, 2018 Pranav Mantini What is color? Color is a psychological property of our visual experiences when we look at objects and lights, not a physical

More information

Biology 70, Lecture 4, Part II Fall 2007

Biology 70, Lecture 4, Part II Fall 2007 color another bad joke 1 2 from lecture outline: COLOR What s wrong here?????? 7. What property of light is responsible for color information? Under white light why does an opaque or translucent blue object

More information

LECTURE III: COLOR IN IMAGE & VIDEO DR. OUIEM BCHIR

LECTURE III: COLOR IN IMAGE & VIDEO DR. OUIEM BCHIR 1 LECTURE III: COLOR IN IMAGE & VIDEO DR. OUIEM BCHIR 2 COLOR SCIENCE Light and Spectra Light is a narrow range of electromagnetic energy. Electromagnetic waves have the properties of frequency and wavelength.

More information

Today. Color. Color and light. Color and light. Electromagnetic spectrum 2/7/2011. CS376 Lecture 6: Color 1. What is color?

Today. Color. Color and light. Color and light. Electromagnetic spectrum 2/7/2011. CS376 Lecture 6: Color 1. What is color? Color Monday, Feb 7 Prof. UT-Austin Today Measuring color Spectral power distributions Color mixing Color matching experiments Color spaces Uniform color spaces Perception of color Human photoreceptors

More information

CIE tri-stimulus experiment. Color Value Functions. CIE 1931 Standard. Color. Diagram. Color light intensity for visual color match

CIE tri-stimulus experiment. Color Value Functions. CIE 1931 Standard. Color. Diagram. Color light intensity for visual color match CIE tri-stimulus experiment diffuse reflecting screen diffuse reflecting screen 770 769 768 test light 382 381 380 observer test light 445 535 630 445 535 630 observer light intensity for visual color

More information

It s a Colorful Life

It s a Colorful Life It s a Colorful Life Dr. Lawrence D. Woolf General Atomics San Diego CA 92121 Presented at the 2000 Southeastern College Art Conference/Mid-America College Art Association Meeting Foundations in Art Theory

More information

KODAK EKTACHROME RADIANCE III Paper

KODAK EKTACHROME RADIANCE III Paper TECHNICAL DATA / COLOR PAPER February 2003 E-1766 KODAK EKTACHROME RADIANCE III Paper NOTICE Discontinuance of KODAK PROFESSIONAL EKTACHROME RADIANCE III Papers and Materials and KODAK EKTACHROME R-3 Chemicals

More information

12/02/2017. From light to colour spaces. Electromagnetic spectrum. Colour. Correlated colour temperature. Black body radiation.

12/02/2017. From light to colour spaces. Electromagnetic spectrum. Colour. Correlated colour temperature. Black body radiation. From light to colour spaces Light and colour Advanced Graphics Rafal Mantiuk Computer Laboratory, University of Cambridge 1 2 Electromagnetic spectrum Visible light Electromagnetic waves of wavelength

More information

Sunderland, NE England

Sunderland, NE England Sunderland, NE England Robert Grosseteste (1175-1253) Bishop of Lincoln Teacher of Francis Bacon Exhibit featuring color ideas of Robert Grosseteste Closes Saturday! Exactly 16 colors: (unnamed) White

More information

Exercises The Color Spectrum (pages ) 28.2 Color by Reflection (pages )

Exercises The Color Spectrum (pages ) 28.2 Color by Reflection (pages ) Exercises 28.1 The Spectrum (pages 555 556) 1. was the first person to do a systematic study of color. 2. Circle the letter of each statement that is true about Newton s study of color. a. He studied sunlight.

More information

Images and Displays. Lecture Steve Marschner 1

Images and Displays. Lecture Steve Marschner 1 Images and Displays Lecture 2 2008 Steve Marschner 1 Introduction Computer graphics: The study of creating, manipulating, and using visual images in the computer. What is an image? A photographic print?

More information

Image Representations, Colors, & Morphing. Stephen J. Guy Comp 575

Image Representations, Colors, & Morphing. Stephen J. Guy Comp 575 Image Representations, Colors, & Morphing Stephen J. Guy Comp 575 Procedural Stuff How to make a webpage Assignment 0 grades New office hours Dinesh Teaching Next week ray-tracing Problem set Review Overview

More information

Color Perception. Color, What is It Good For? G Perception October 5, 2009 Maloney. perceptual organization. perceptual organization

Color Perception. Color, What is It Good For? G Perception October 5, 2009 Maloney. perceptual organization. perceptual organization G892223 Perception October 5, 2009 Maloney Color Perception Color What s it good for? Acknowledgments (slides) David Brainard David Heeger perceptual organization perceptual organization 1 signaling ripeness

More information

Section 18.3 Behavior of Light

Section 18.3 Behavior of Light Light and Materials When light hits an object it can be Section 18.3 Behavior of Light Light and Materials Objects can be classified as Transparent Translucent Opaque Transparent, Translucent, Opaque Transparent

More information

Figure 1: Energy Distributions for light

Figure 1: Energy Distributions for light Lecture 4: Colour The physical description of colour Colour vision is a very complicated biological and psychological phenomenon. It can be described in many different ways, including by physics, by subjective

More information

Colors in Images & Video

Colors in Images & Video LECTURE 8 Colors in Images & Video CS 5513 Multimedia Systems Spring 2009 Imran Ihsan Principal Design Consultant OPUSVII www.opuseven.com Faculty of Engineering & Applied Sciences 1. Light and Spectra

More information

Color Theory. Additive Color

Color Theory. Additive Color Color Theory A primary color is a color that cannot be made from a combination of any other colors. A secondary color is a color created from a combination of two primary colors. Tertiary color is a combination

More information

Our senses don t deceive us; our judgment does. Johann Wolfgang von Goethe

Our senses don t deceive us; our judgment does. Johann Wolfgang von Goethe Our senses don t deceive us; our judgment does. Johann Wolfgang von Goethe 1 ULTRAVIOLET X-RAYS GAMMA RAYS VISIBLE MICROWAVES SPECTRUM INFRARED RADIO WAVES VIOLET BLUE CYAN GREEN YELLOW RED MAGENTA The

More information

Lecture Color Image Processing. by Shahid Farid

Lecture Color Image Processing. by Shahid Farid Lecture Color Image Processing by Shahid Farid What is color? Why colors? How we see objects? Photometry, Radiometry and Colorimetry Color measurement Chromaticity diagram Shahid Farid, PUCIT 2 Color or

More information

Colour Management Workflow

Colour Management Workflow Colour Management Workflow The Eye as a Sensor The eye has three types of receptor called 'cones' that can pick up blue (S), green (M) and red (L) wavelengths. The sensitivity overlaps slightly enabling

More information

EECS490: Digital Image Processing. Lecture #12

EECS490: Digital Image Processing. Lecture #12 Lecture #12 Image Correlation (example) Color basics (Chapter 6) The Chromaticity Diagram Color Images RGB Color Cube Color spaces Pseudocolor Multispectral Imaging White Light A prism splits white light

More information

CS 565 Computer Vision. Nazar Khan PUCIT Lecture 4: Colour

CS 565 Computer Vision. Nazar Khan PUCIT Lecture 4: Colour CS 565 Computer Vision Nazar Khan PUCIT Lecture 4: Colour Topics to be covered Motivation for Studying Colour Physical Background Biological Background Technical Colour Spaces Motivation Colour science

More information

Reflection and Color

Reflection and Color CHAPTER 16 13 SECTION Sound and Light Reflection and Color KEY IDEAS As you read this section, keep these questions in mind: What happens to light when it hits an object? Why can you see an image in a?

More information

Printing Devices. Lecture 10. Older Printing Devices. Ink Jet Printer. Thermal-Bubble Ink Jet Printer. Plotter. Dot Matrix Printer

Printing Devices. Lecture 10. Older Printing Devices. Ink Jet Printer. Thermal-Bubble Ink Jet Printer. Plotter. Dot Matrix Printer Lecture 10 Older Printing Devices Printing Devices Ink Jet Printers Laser Printers Thermal Printers Dye Sublimation Halftoning Dithering Error Diffusion Plotter Dot Matrix Printer pin motion ink covered

More information

Myth #1. Blue, cyan, green, yellow, red, and magenta are seen in the rainbow.

Myth #1. Blue, cyan, green, yellow, red, and magenta are seen in the rainbow. Myth #1 Blue, cyan, green, yellow, red, and magenta are seen in the rainbow. a. The spectrum does not include magenta; cyan is a mixture of blue and green light; yellow is a mixture of green and red light.

More information

TEACH THE CORRECT COLOR THEORY SCHOOL

TEACH THE CORRECT COLOR THEORY SCHOOL Page 1 of 7 TEACH THE CORRECT COLOR THEORY IN SCHOOL Teachers in public schools are still teaching the wrong color theory to children. Here is a list of reasons why this is done, why it is wrong for teachers

More information

Color. Chapter 6. (colour) Digital Multimedia, 2nd edition

Color. Chapter 6. (colour) Digital Multimedia, 2nd edition Color (colour) Chapter 6 Digital Multimedia, 2nd edition What is color? Color is how our eyes perceive different forms of energy. Energy moves in the form of waves. What is a wave? Think of a fat guy (Dr.

More information

Colors in images. Color spaces, perception, mixing, printing, manipulating...

Colors in images. Color spaces, perception, mixing, printing, manipulating... Colors in images Color spaces, perception, mixing, printing, manipulating... Tomáš Svoboda Czech Technical University, Faculty of Electrical Engineering Center for Machine Perception, Prague, Czech Republic

More information

Chapter 4. Incorporating Color Techniques

Chapter 4. Incorporating Color Techniques Chapter 4 Incorporating Color Techniques Color Modes Photoshop displays and prints images using specific color modes A mode is the amount of color data that can be stored in a given file format 2 Color

More information

Lecture 8. Color Image Processing

Lecture 8. Color Image Processing Lecture 8. Color Image Processing EL512 Image Processing Dr. Zhu Liu zliu@research.att.com Note: Part of the materials in the slides are from Gonzalez s Digital Image Processing and Onur s lecture slides

More information

Color April 16 th, 2015

Color April 16 th, 2015 Color April 16 th, 2015 Yong Jae Lee UC Davis Today Measuring color Spectral power distributions Color mixing Color matching experiments Color spaces Uniform color spaces Perception of color Human photoreceptors

More information

Color. April 16 th, Yong Jae Lee UC Davis

Color. April 16 th, Yong Jae Lee UC Davis Color April 16 th, 2015 Yong Jae Lee UC Davis Measuring color Today Spectral power distributions Color mixing Color matching experiments Color spaces Uniform color spaces Perception of color Human photoreceptors

More information

Color Science. What light is. Measuring light. CS 4620 Lecture 15. Salient property is the spectral power distribution (SPD)

Color Science. What light is. Measuring light. CS 4620 Lecture 15. Salient property is the spectral power distribution (SPD) Color Science CS 4620 Lecture 15 1 2 What light is Measuring light Light is electromagnetic radiation Salient property is the spectral power distribution (SPD) [Lawrence Berkeley Lab / MicroWorlds] exists

More information

Color Theory. Chapter 2 Color Basics

Color Theory. Chapter 2 Color Basics Chapter 2 Color Basics Color Theory Intrinsic Value Primary/Secondary/Tertiary Strict vs. Chromatic Neutral, Tint, Shade, Tone Analogous/Adjacent Local vs. Atmospheric Clr Color & temperature Pigment vs.

More information

LECTURE 07 COLORS IN IMAGES & VIDEO

LECTURE 07 COLORS IN IMAGES & VIDEO MULTIMEDIA TECHNOLOGIES LECTURE 07 COLORS IN IMAGES & VIDEO IMRAN IHSAN ASSISTANT PROFESSOR LIGHT AND SPECTRA Visible light is an electromagnetic wave in the 400nm 700 nm range. The eye is basically similar

More information

Unit 8: Color Image Processing

Unit 8: Color Image Processing Unit 8: Color Image Processing Colour Fundamentals In 666 Sir Isaac Newton discovered that when a beam of sunlight passes through a glass prism, the emerging beam is split into a spectrum of colours The

More information

Color and Perception. CS535 Fall Daniel G. Aliaga Department of Computer Science Purdue University

Color and Perception. CS535 Fall Daniel G. Aliaga Department of Computer Science Purdue University Color and Perception CS535 Fall 2014 Daniel G. Aliaga Department of Computer Science Purdue University Elements of Color Perception 2 Elements of Color Physics: Illumination Electromagnetic spectra; approx.

More information

Twelve significant photographs in any one year is a good crop. - Ansel Adams. Color. Introduc)on to Digital Photography

Twelve significant photographs in any one year is a good crop. - Ansel Adams. Color. Introduc)on to Digital Photography Twelve significant photographs in any one year is a good crop. - Ansel Adams Color Introduc)on to Digital Photography Lecture outline How we see color Addi)ve (RGB) / Subtrac)ve (CMYK) HSB Hue Satura)on

More information

Achim J. Lilienthal Mobile Robotics and Olfaction Lab, AASS, Örebro University

Achim J. Lilienthal Mobile Robotics and Olfaction Lab, AASS, Örebro University Achim J. Lilienthal Mobile Robotics and Olfaction Lab, Room T1227, Mo, 11-12 o'clock AASS, Örebro University (please drop me an email in advance) achim.lilienthal@oru.se 1 2. General Introduction Schedule

More information

To discuss. Color Science Color Models in image. Computer Graphics 2

To discuss. Color Science Color Models in image. Computer Graphics 2 Color To discuss Color Science Color Models in image Computer Graphics 2 Color Science Light & Spectra Light is an electromagnetic wave It s color is characterized by its wavelength Laser consists of single

More information

10.2 Color and Vision

10.2 Color and Vision 10.2 Color and Vision The energy of light explains how different colors are physically different. But it doesn't explain how we see colors. How does the human eye see color? The answer explains why computers

More information

PERCEIVING COLOR. Functions of Color Vision

PERCEIVING COLOR. Functions of Color Vision PERCEIVING COLOR Functions of Color Vision Object identification Evolution : Identify fruits in trees Perceptual organization Add beauty to life Slide 2 Visible Light Spectrum Slide 3 Color is due to..

More information

Understanding Color Theory Excerpt from Fundamental Photoshop by Adele Droblas Greenberg and Seth Greenberg

Understanding Color Theory Excerpt from Fundamental Photoshop by Adele Droblas Greenberg and Seth Greenberg Understanding Color Theory Excerpt from Fundamental Photoshop by Adele Droblas Greenberg and Seth Greenberg Color evokes a mood; it creates contrast and enhances the beauty in an image. It can make a dull

More information

Future Electronics EZ-Color Seminar. Autumn Colour Technology

Future Electronics EZ-Color Seminar. Autumn Colour Technology Polymer Optics Ltd. 6 Kiln Ride, Wokingham Berks, RG40 3JL, England Tel/Fax:+44 (0)1189 893341 www.polymer-optics.co.uk Future Electronics EZ-Color Seminar Autumn 2007 Colour Technology Mike Hanney Technical

More information