How Pixels Work

Total Page：16

File Type：pdf, Size：1020Kb

How Pixels Work A look at how images are displayed on a computer Before creating digital art, it’s important to understand how your computer displays images. This lesson covers the following material: Primary Colors… of a Computer What is a Pixel The Big Picture The Primary Colors… of a Computer In school you were probably taught that the primary colors were Red, Yellow, and Blue and that with those colors you can make any other color. Computers are very similar, but they have a different set of primary colors. Computers use Red, Green, and Blue (a.k.a. RGB). The Primary Colors… How RGB Works As you combine the colors Red, Green, and Blue, you start to get other colors. – Full RGB = white – No RGB = Black – Full Red + Full Green = Yellow – Adding a little blue to that yellow will change it to be closer to white. – Lessoning the green from the yellow will make it be more and more orange/red. What is a pixel Rather than mixing colors like you typically would with paint, computer rely on placing those three colors (RGB) into very small, tightly compact spaces to make it appear that they are mixed into a single color. This tiny, compact space is called a pixel. What is a pixel – A zoomed look The image below shows a program that creates colors based off of the RGB color model. It can be difficult to see, at first, how colors like Red+blue (and black, representing an absence of green) can be placed closely enough to represent that magenta color. What is a pixel – the shrunken effect Notice how every time you shrink the “pixels” they blend more and more into each other, appearing to be magenta. Another example: The Big Picture Multiple pixels can be bunched together into a tiny space to represent an image. You can see the individual pixels in this image. The Big Picture You can see here how the pixels are visible when zoomed in, but when zoomed out they blend pretty well. The summary 1. Computers use combinations of Red, Green, and Blue to create any color. 2. RGB colors are combined into compact spaces to create pixels 3. Pixels are combined into compact spaces to create images Image Sources • RGB image by Ntozis at Greek Wikipedia • Pixel transition images from the PixelChanger program, created by Judson Birkel. • Ninja Turtle image created by Judson Birkel .

Copy Link

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]