DOCSLIB.ORG

RYB Color Compositing

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
RYB Color Compositing RYB Color Compositing Junichi Sugita Tokiichiro Takahashi Tokyo Healthcare University / Tokyo Denki University Tokyo Denki University / UEI Research Tokyo, Japan Tokyo, Japan [email protected] [email protected] (a) RGB color compositing (b) RYB color compositing (c) Itten’s RYB color wheel (d) Stroke compositing in RYB color space Fig. 1. Intuitive color compositing Abstract—This paper introduce an equation to convert from Red and yellow makes orange, yellow and blue makes green, RGB to RYB and the inverse conversion equation as a model of and red and blue makes purple. Composited three colors get RYB color space. Proposal RYB color model allows paint like close to black (See Fig. 1. (b)). compositing easily without complex configuration of parameters such as Kubelka-Munk model. Meanwhile, there is a physical model for compositing pigments such as that of KM model [3], [4], [5]. The KM Keywords— RYB; Color; Compositing; Mixing model is able to analytically calculate reflectance and transparency of scattering materials such as paint pigment. I. INTRODUCTION However, it is difficult to use because the KM model requires many parameters. In addition, KM model has the limitation of Color compositing is a commonly used operation in usable colors due to a requirement of predefined pigment computer graphics. There are two general approach: either library. compositing in RGB color space, or physical model using Kubelka-Munk (KM) theory [1]. However, the former fails to For compositing colors that more closely resemble the reproduce paint like appearances, while the latter is difficult to expectations of those not trained in the RGB color space, the use. RYB color space is thought of as intuitive approach. For this reason, modelization of the RYB color space on computer is Most computer graphics applications make use of the RGB useful and several application can be expected. color space which is defined by the three chromaticities of the red, green, and blue primaries. The RGB color model is an This paper introduce an equation to convert from RGB to additive color model (See Fig. 1. (a)). Simple alpha blending in RYB and the inverse conversion equation. By converting RYB RGB color space maps onto the traditional color compositing color space with the conversion equation, we regain normal use pipeline. However, RGB color compositing fails to reproduce of simple color compositing method in RYB color space, for paint like appearance such as “yellow and blue makes green”. example alpha-blending, without complex configuration of parameters such as KM model. Experimental results verify the CMYK is well known color model for subtractive color effectiveness of proposal RYB color model. compositing used in printing. Similar to RGB, CMYK also fails to reproduce paint like appearance. II. RELATED WORK Many people have been used subtractive color model based There are a number of extensive studies on physical on pigment color compositing since early childhood. RYB pigment model to calculate the compositing color for realistic color model by Johannes Itten is widely used in art education natural digital media painting system. However, there is few [2]. Fig. 1. (c) shows Itten’s RYB color wheel. In the RYB study on converting color space from RGB to RYB. color model, red, yellow and blue are defined as primary colors. Several digital media painting system have used KM model Here, min() is a function for calculating min value from input for producing composited colors [3], [4], [5]. Baxter et al. [6] arguments. RYB values, rryb, yryb, bryb, are obtained from rrgb, proposed a strokes paint system using KM model with a grgb, brgb by the following equation. numerical approximation of the same pigments. Curtis et al. [6] r r min(r , g ) used reduced KM model for rendering watercolor. Wang and ryb rgb rgb rgb Wang [7] proposed further approximation which uses a single grgb min(rrgb , grgb ) (3) y coefficient variant of KM model. The wax crayon simulation of ryb 2 Rudolf et al. [8] uses simple approximation of KM model. b g min(r , g ) b rgb rgb rgb rgb However, KM model is difficult to use because this model ryb 2 requires many parameters. Moreover, usable colors is limited We normalize the equation (3) as: to the number of predefined pigment library. rryb r In order to improve the problem, Lu et al. [10] proposed a ryb n data-driven model for compositing colors. Although this model y (4) not requires complex configuration of parameters but requires ryb yryb n 0 predefined colors as an input. n b Gossett and Chen [11] proposed paint inspired RYB color ryb bryb model. As far as we examined, this is the only research to n convert from RGB to RYB. Gossett and Chen defined three Here, n is calculated as follows: paint pigment primaries and tri-linearly interpolated among max(r , y ,b ) them. However, this model is irreversible conversion, because n ryb ryb ryb (5) interpolated color is depend on defined pigment primary colors. max(rrgb , grgb ,brgb ) And this paper do not provided clear mechanism for converting Here, max() is a function for calculating max value from input RYB to RGB. arguments. These and other studies provided useful information. Finally, black component are added for subtractive color However, the conversion equation from RGB to RYB has not mixing, and RYB values, Rryb, Yryb, Bryb, are obtained as been generally provided in the literature. follows: III. RYB COLOR MODEL Rryb rryb Ib In this chapter, we describe the method of interconversion (6) Yryb yryb Ib between RGB and RYB color space. Ideal correspondence values between RGB to RYB show Table 1. The number of Bryb bryb Ib each RGB or RYB channel ranges from 0 to 1. We propose the Here, I can be calculated as follows: conversion equation in agreement with the values of Table 1. b Ib min(1 Rrgb ,1 Grgb ,1 Brgb ) (7) TABLE 1. CORRESPONDING VALUES BETWEEN RGB AND RYB Color RGB RYB (0, 0, 0) (1, 1, 1) B. RYB to RGB Conversion (1, 0, 0) (1, 0, 0) In this section, we describe the conversion from RGB to (0, 1, 0) (0, 1, 1) (0, 0, 1) (0, 0, 1) RYB. Rryb, Yryb, Bryb are given RYB values as an input. (1, 1, 0) (0, 1, 0) Whiteness component is removed from Rryb, Yryb, Bryb by the (1, 0, 1) (1, 0, 0.5) following equation. (0, 1, 1) (0, 0.5, 1) (1, 1, 1) (0, 0, 0) rryb Rryb I w (8) A. RGB to RYB Conversion yryb Yryb I w We introduce how to make the conversion from the RGB to bryb Brgb I w RYB color space. Rrgb, Grgb, Brgb are given RGB values as an Here, I is calculated as follows: input. Whiteness component is removed from R , G , B by w rgb rgb rgb I min(R ,Y , B ) (9) the following equation. w ryb ryb ryb RGB values, rrgb, grgb, brgb, are obtained from rryb, yryb, bryb by rrgb Rrgb I w the following equation. (1) g rgb Grgb I w rrgb rryb yryb min(yryb ,bryb ) (10) brgb Brgb I w gryb yryb 2min(yryb ,bryb ) Here, Iw can be calculated as follows: brgb 2bryb min(yryb ,bryb ) I min(R ,G , B ) w rgb rgb rgb (2) We normalize the equation (10) as: show results as luminance = 200. Fig. 2. (c) is brighter than Fig. rrgb rrgb 2. (a) because RGB is additive color model. On the other hand, n Fig. 2. (d) is darker than Fig. 2. (b). It means that the proposed grgb (11) RYB color model realized subtractive color model. grgb n 0 n brgb brgb n Here, n is calculated as follows: max(r , g ,b ) n ryb ryb ryb (12) max(rrgb , yrgb ,brgb ) Finally, black component are added, and RGB values, Rrgb, Grgb, Brgb, are obtained as follows: Rrgb rrgb Ib (13) Grgb grgb Ib (a) RGB (Luminance = 100) Brgb brgb Ib Here, Ib can be calculated as follows: Ib min(1 Rryb ,1Yryb ,1 Bryb ) (14) IV. EXPERIMENTAL RESULTS To verify effectiveness of proposed RYB model, the authors performed several experiments. A. Results of Color Compositing Fig. 1. (b) shows the result using proposed RYB color model. Composited color Ccomp is calculated from two colors, (b) RYB (Luminance = 100) C1, C2, by following equation. Ccomp C1 C2 (15) As shown in Fig. 1. (b), we could observe the paint like compositing such as “yellow and blue make green”. Fig. 1. (d) shows result of stroke compositing in the proposed RYB color space. This results used alpha blending method which is defined by following equation. Cblend C1 1 C2 (16) Cblend is composited color from C1 and C2. α is 0.5 in Fig. 1. (d). As shown in Fig. 1. (d), we could observe the paint like appearance. By using the proposed RYB color space, we (c) RGB (Luminance = 200) regain normal use of simple alpha blending method for compositing colors. The proposed RYB color model allows paint like compositing easily without complex configuration of parameters such as Kubelka-Munk model. B. Whole context of proposed RYB Color Model To understand the whole context of the proposed RYB color model, we converted from RYB to HSL color space. For comparison, we also converted from RGB to HSL color space. Fig. 2. shows relationship between hue and saturation in HSL color space. The vertical axis is luminance, the horizontal axis is hue. The number of hue ranges from 0 to 360, saturation and luminance ranges from 0 to 255. Fig. 2. (a) and (b) show (d) RYB (Luminance = 200) results for the case of luminance = 100.
Load more

Recommended publications
  • Chapter 2 Fundamentals of Digital Imaging
    Chapter 2 Fundamentals of Digital Imaging Part 4 Color Representation © 2016 Pearson Education, Inc., Hoboken, 1 NJ. All rights reserved. In this lecture, you will find answers to these questions • What is RGB color model and how does it represent colors? • What is CMY color model and how does it represent colors? • What is HSB color model and how does it represent colors? • What is color gamut? What does out-of-gamut mean? • Why can't the colors on a printout match exactly what you see on screen? © 2016 Pearson Education, Inc., Hoboken, 2 NJ. All rights reserved. Color Models • Used to describe colors numerically, usually in terms of varying amounts of primary colors. • Common color models: – RGB – CMYK – HSB – CIE and their variants. © 2016 Pearson Education, Inc., Hoboken, 3 NJ. All rights reserved. RGB Color Model • Primary colors: – red – green – blue • Additive Color System © 2016 Pearson Education, Inc., Hoboken, 4 NJ. All rights reserved. Additive Color System © 2016 Pearson Education, Inc., Hoboken, 5 NJ. All rights reserved. Additive Color System of RGB • Full intensities of red + green + blue = white • Full intensities of red + green = yellow • Full intensities of green + blue = cyan • Full intensities of red + blue = magenta • Zero intensities of red , green , and blue = black • Same intensities of red , green , and blue = some kind of gray © 2016 Pearson Education, Inc., Hoboken, 6 NJ. All rights reserved. Color Display From a standard CRT monitor screen © 2016 Pearson Education, Inc., Hoboken, 7 NJ. All rights reserved. Color Display From a SONY Trinitron monitor screen © 2016 Pearson Education, Inc., Hoboken, 8 NJ.
    [Show full text]
  • Computational RYB Color Model and Its Applications
    IIEEJ Transactions on Image Electronics and Visual Computing Vol.5 No.2 （2017） -- Special Issue on Application-Based Image Processing Technologies -- Computational RYB Color Model and its Applications Junichi SUGITA† (Member), Tokiichiro TAKAHASHI†† (Member) †Tokyo Healthcare University, ††Tokyo Denki University/UEI Research <Summary> The red-yellow-blue (RYB) color model is a subtractive model based on pigment color mixing and is widely used in art education. In the RYB color model, red, yellow, and blue are defined as the primary colors. In this study, we apply this model to computers by formulating a conversion between the red-green-blue (RGB) and RYB color spaces. In addition, we present a class of compositing methods in the RYB color space. Moreover, we prescribe the appropriate uses of these compo- siting methods in different situations. By using RYB color compositing, paint-like compositing can be easily achieved. We also verified the effectiveness of our proposed method by using several experiments and demonstrated its application on the basis of RYB color compositing. Keywords: RYB, RGB, CMY(K), color model, color space, color compositing man perception system and computer displays, most com- 1. Introduction puter applications use the red-green-blue (RGB) color mod- Most people have had the experience of creating an arbi- el3); however, this model is not comprehensible for many trary color by mixing different color pigments on a palette or people who not trained in the RGB color model because of a canvas. The red-yellow-blue (RYB) color model proposed its use of additive color mixing. As shown in Fig.
    [Show full text]
  • C9600 Printing Guide V1.0
    Copyright Information Copyright © 2007 by Oki Data. All Rights Reserved Document Information ________________________________ C9600 Printing Guide P/N 59373001 Revision 3.0 February, 2007 Disclaimer__________________________________________ Every effort has been made to ensure that the information in this document is complete, accurate, and up-to-date. The manufacturer assumes no responsibility for the results of errors beyond its control. The manufacturer also cannot guarantee that changes in software and equipment made by other manufacturers and referred to in this guide will not affect the applicability of the information in it. Mention of software products manufactured by other companies does not necessarily constitute endorsement by the manufacturer . While all reasonable efforts have been made to make this document as accurate and helpful as possible, we make no warranty of any kind, expressed or implied, as to the accuracy or completeness of the information contained herein. The most up-to-date drivers and manuals are available from the web site: http://www.okiprintingsolutions.com Trademark Information _______________________________ Oki and Oki Printing Solutions are registered trademarks of Oki Electric Industry Company Ltd. Adobe and PostScript are registered trademarks of Adobe Systems. Apple, Macintosh, Mac, and Mac OS are registered trademarks of Apple Computers Inc. Hewlett-Packard, HP, and LaserJet are registered trademarks of Hewlett-Packard Company. Microsoft, MS-DOS and Windows are either registered trademarks or trademarks
    [Show full text]
  • Basics of Color Management
    Application Notes Basics of Color Management Basics of Color Management ErgoSoft AG Moosgrabenstr. 13 CH-8595 Altnau, Switzerland © 2010 ErgoSoft AG, All rights reserved. The information contained in this manual is based on information available at the time of publication and is sub- ject to change without notice. Accuracy and completeness are not warranted or guaranteed. No part of this manual may be reproduced or transmitted in any form or by any means, including electronic me- dium or machine-readable form, without the expressed written permission of ErgoSoft AG. Brand or product names are trademarks of their respective holders. The ErgoSoft RIP is available in different editions. Therefore the description of available features in this document does not necessarily reflect the license details of your edition of the ErgoSoft RIP. For information on the features included in your edition of the ErgoSoft RIPs refer to the ErgoSoft homepage or contact your dealer. Rev. 1.1 Basics of Color Management i Contents Introduction ................................................................................................................................................................. 1 Color Spaces ................................................................................................................................................................ 1 Basics ........................................................................................................................................................................ 1 CMYK .......................................................................................................................................................................
    [Show full text]
  • Fabrication of Rainbow Holograms Using SEM Based E-Beam Lithography
    Fabrication of digital rainbow holograms and 3- D imaging using SEM based e-beam lithography An. Firsov,1,2,* A. Firsov,2 B. Loechel,1 A. Erko,1 A. Svintsov2 and S. Zaitsev2 1Helmholtz-Zentrum Berlin für Materialien und Energie (HZB), Albert-Einstein-Str. 15, 12489 Berlin, Germany 2Institute of Microelectronics Technology and High Purity Materials RAS, 142432 Chernogolovka, Moscow region, Russia * [email protected] Abstract: Here we present an approach for creating full-color digital rainbow holograms based on mixing three basic colors. Much like in a color TV with three luminescent points per single screen pixel, each color pixel of initial image is presented by three (R, G, B) distinct diffractive gratings in a hologram structure. Change of either duty cycle or area of the gratings are used to provide proper R, G, B intensities. Special algorithms allow one to design rather complicated 3D images (that might even be replacing each other with hologram rotation). The software developed (“RainBow”) provides stability of colorization of rotated image by means of equalizing of angular blur from gratings responsible for R, G, B basic colors. The approach based on R, G, B color synthesis allows one to fabricate gray-tone rainbow hologram containing white color what is hardly possible in traditional dot-matrix technology. Budgetary electron beam lithography based on SEM column was used to fabricate practical examples of digital rainbow hologram. The results of fabrication of large rainbow holograms from design to imprinting are presented. Advantages of the EBL in comparison to traditional optical (dot-matrix) technology is considered.
    [Show full text]
  • 12. Optical Data Storage
    12. Optical data storage 12.1 Theory of color RGB additive color model B B Blue Magenta (0.6, 0.2, 1) (0,0,1) (1,0,1) Gray shades Cyan (g,g,g) (0,1,1) White (1,1,1) (0.6, 1, 0.7) R R Black Red (0,0,0) (1,0,0) G Green (0,1,0) (1, 0.7, 0.1) Yellow (1,1,0) G The RGB color model converts the additive color mixing system into a digital system, in which any color is represented by a point in a color tridimensional space and thus by a three coordinates vector. The coordinates are composed of the respective proportions of the primary light colors (Red, Green, Blue). The RGB model is often used by software as it requires no conversion in order to display colors on a computer screen. 169 CMY subtractive color model Y Y Yellow Green (0, 0.3, 0.9) (0,0,1) (1,0,1) Gray shades Red (g,g,g) (0,1,1) Black (1,1,1) C (0.4, 0, 0.3) C White Cyan (0,0,0) (1,0,0) M Magenta (0,1,0) (0.4, 0.8, 0) Blue (1,1,0) M The CMY color model corresponds to the subtractive color mixing system. The coordinates of a point in this color space are composed of the respective proportions of the primary filter colors (Cyan, Magenta, Yellow). The CMY model is used whenever a colored document is printed. The conversion RGB and CMY models can be written as follows: For the orange point, for example: 170 HSV color model V Green Yellow 120° 60° (37°, 0.9, 1) White H 1.0 S Cyan Red 180° 0° V Blue Magenta 240° 300° Hue is given in polar coordinate.
    [Show full text]
  • Fiery Color Reference C9800 OKI Americas Inc
    2Copyright Copyright Sharp AR-C360P EFI Color Reference Guide P/N 59379101, Revision 1.1 September, 2005 Every effort has been made to ensure that the information in this document is complete, accurate, and up-to-date. The manufacturer assumes no responsibility for the results of errors beyond its control. The manufacturer also cannot guarantee that changes in software and equipment made by other manufacturers and referred to in this guide will not affect the applicability of the information in it. Mention of software products manufactured by other companies does not necessarily constitute endorsement by the manufacturer. While all reasonable efforts have been made to make this document as accurate and helpful as possible, we make no warranty of any kind, expressed or implied, as to the accuracy or completeness of the information contained herein. The most up-to-date drivers and manuals are available from the web site: http://www.sharpusa.com Copyright © 2005 Sharp Electronics Corporation and its suppliers and Electronics for Imaging, Inc. All rights reserved. This publication is protected by copyright, and all rights are reserved. No part of it may be reproduced or transmitted in any form or by any means for any purpose without express prior written consent from Electronics for Imaging, Inc. Information in this document is subject to change without notice and does not represent a commitment on the part of Electronics for Imaging, Inc. This publication is provided in conjunction with an EFI product (the “Product”) which contains EFI software (the “Software”). The Software is furnished under license and may only be used or copied in accordance with the terms of the Software license set forth below.
    [Show full text]
  • 14. Color Mapping
    14. Color Mapping Jacobs University Visualization and Computer Graphics Lab Recall: RGB color model Jacobs University Visualization and Computer Graphics Lab Data Analytics 691 CMY color model • The CMY color model is related to the RGB color model. •Itsbasecolorsare –cyan(C) –magenta(M) –yellow(Y) • They are arranged in a 3D Cartesian coordinate system. • The scheme is subtractive. Jacobs University Visualization and Computer Graphics Lab Data Analytics 692 Subtractive color scheme • CMY color model is subtractive, i.e., adding colors makes the resulting color darker. • Application: color printers. • As it only works perfectly in theory, typically a black cartridge is added in practice (CMYK color model). Jacobs University Visualization and Computer Graphics Lab Data Analytics 693 CMY color cube • All colors c that can be generated are represented by the unit cube in the 3D Cartesian coordinate system. magenta blue red black grey white cyan yellow green Jacobs University Visualization and Computer Graphics Lab Data Analytics 694 CMY color cube Jacobs University Visualization and Computer Graphics Lab Data Analytics 695 CMY color model Jacobs University Visualization and Computer Graphics Lab Data Analytics 696 CMYK color model Jacobs University Visualization and Computer Graphics Lab Data Analytics 697 Conversion • RGB -> CMY: • CMY -> RGB: Jacobs University Visualization and Computer Graphics Lab Data Analytics 698 Conversion • CMY -> CMYK: • CMYK -> CMY: Jacobs University Visualization and Computer Graphics Lab Data Analytics 699 HSV color model • While RGB and CMY color models have their application in hardware implementations, the HSV color model is based on properties of human perception. • Its application is for human interfaces. Jacobs University Visualization and Computer Graphics Lab Data Analytics 700 HSV color model The HSV color model also consists of 3 channels: • H: When perceiving a color, we perceive the dominant wavelength.
    [Show full text]
  • Color Management the Basics Simply Explained
    How-to: AccurioPro Flux Color management The basics simply explained In this How-to, we explain why color management is necessary and what happens in the background. AccurioPro Flux | Color management: The basics simply explained The colors in a print job can come from different sources: Images from cameras or scanners, as well as graphics, text and layout from various applications. In each source, color can be defined differently. Also the output of each printer is a little different. One printer can print many colors, another only a few. Even printers of the same type and manufacturer always print colors a little differently. In addition, the color rendering is influenced by the toner used and the selected paper. With good color management, it is possible to control the colors in the print job and set up a color-constant printing process. The aim is to achieve a constant color rendering across the various printers and papers according to a predefined standard. If you print a job on different printers with the same paper, you get consistent color rendering. If a customer orders a print job at a later date, they receive an output in the same colors as for the initial order. A few basics in advance for a better understanding: What is a color space A color space includes all the colors that a device or medium can display. The larger a color space is, the more colors can be displayed. Each printer and monitor has its own color space. These color spaces vary in size so that different monitors and printers can display different numbers of colors.
    [Show full text]
  • Human Skin Detection Using RGB, HSV and Ycbcr Color Models
    Human Skin Detection Using RGB, HSV and YCbCr Color Models S. Kolkur1, D. Kalbande2, P. Shimpi2, C. Bapat2, and J. Jatakia2 1 Department of Computer Engineering, Thadomal Shahani Engineering College, Bandra,Mumbai, India 2 Department of Computer Engineering, Sardar Patel Institute of Technology, Andheri,Mumbai, India { [email protected]; [email protected]; [email protected]; [email protected]; [email protected]} Abstract. Human Skin detection deals with the recognition of skin-colored pixels and regions in a given image. Skin color is often used in human skin detection because it is invariant to orientation and size and is fast to pro- cess. A new human skin detection algorithm is proposed in this paper. The three main parameters for recogniz- ing a skin pixel are RGB (Red, Green, Blue), HSV (Hue, Saturation, Value) and YCbCr (Luminance, Chromi- nance) color models. The objective of proposed algorithm is to improve the recognition of skin pixels in given images. The algorithm not only considers individual ranges of the three color parameters but also takes into ac- count combinational ranges which provide greater accuracy in recognizing the skin area in a given image. Keywords: Skin Detection, Color Models, Image Processing, Classifier 1 Introduction Skin detection is the process of finding skin-colored pixels and regions in an image or a video. This process is typically used as a preprocessing step to find regions that potentially have human faces and limbs in images [2]. Skin image recognition is used in a wide range of image processing applications like face recognition, skin dis- ease detection, gesture tracking and human-computer interaction [1].
    [Show full text]
  • Color Gamuts of Different Color Spaces
    Color Gamuts of different color spaces A. Visual gamut B. RGB color space C. CMYK color space The range of color encompassed by a color space is called a gamut. The different devices (computer monitor, scanner, desktop printer, printing press, digital camera) throughout your workflow operate within different color spaces and each with different gamuts. Some colors within the gamut of your computer monitor are not within the gamut of your inkjet printer, and vice versa. When a color cannot be produced on a device, it’s considered to be outside the color space of that particular device. In other words, the color is out of gamut. We use color models to describe the colors we see and work with in digital graphics. Each color model, such as RGB, CMYK, or HSB, represents a different method for describing and classifying color. Color models use numeric values to represent the visible spectrum of color. A color space is a variant of a color model and has a specific gamut (range) of colors. For example, within the RGB color model are a number of color spaces: Adobe RGB, sRGB, and Apple RGB. While each of these color spaces defines color using the same three axes (R, G, and B), their gamuts are different. When you work with the colors in a graphic, you are actually adjusting numerical values in the file. It’s easy to think of a number as a color, but these numerical values are not absolute colors in themselves—they only have a color meaning within the color space of the device that is producing the color.
    [Show full text]
  • Color Image Processing Color Fundamentals
    Image Processing Lecture 15 Color Image Processing The use of color is important in image processing because: · Color is a powerful descriptor that simplifies object identification and extraction. · Humans can discern thousands of color shades and intensities, compared to about only two dozen shades of gray. Color image processing is divided into two major areas: · Full-color processing: images are acquired with a full-color sensor, such as a color TV camera or color scanner. · Pseudocolor processing: The problem is one of assigning a color to a particular monochrome intensity or range of intensities. Color Fundamentals Colors are seen as variable combinations of the primary colors of light: red (R), green (G), and blue (B). The primary colors can be mixed to produce the secondary colors: magenta (red+blue), cyan (green+blue), and yellow (red+green). Mixing the three primaries, or a secondary with its opposite primary color, produces white light. Figure 15.1 Primary and secondary colors of light RGB colors are used for color TV, monitors, and video cameras. ©Asst. Lec. Wasseem Nahy Ibrahem Page 1 Image Processing Lecture 15 However, the primary colors of pigments are cyan (C), magenta (M), and yellow (Y), and the secondary colors are red, green, and blue. A proper combination of the three pigment primaries, or a secondary with its opposite primary, produces black. Figure 15.2 Primary and secondary colors of pigments CMY colors are used for color printing. Color characteristics The characteristics used to distinguish one color from another are: · Brightness: means the amount of intensity (i.e. color level).
    [Show full text]