Color Gamuts of Different Color Spaces
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Color Models
Color Models Jian Huang CS456 Main Color Spaces • CIE XYZ, xyY • RGB, CMYK • HSV (Munsell, HSL, IHS) • Lab, UVW, YUV, YCrCb, Luv, Differences in Color Spaces • What is the use? For display, editing, computation, compression, …? • Several key (very often conflicting) features may be sought after: – Additive (RGB) or subtractive (CMYK) – Separation of luminance and chromaticity – Equal distance between colors are equally perceivable CIE Standard • CIE: International Commission on Illumination (Comission Internationale de l’Eclairage). • Human perception based standard (1931), established with color matching experiment • Standard observer: a composite of a group of 15 to 20 people CIE Experiment CIE Experiment Result • Three pure light source: R = 700 nm, G = 546 nm, B = 436 nm. CIE Color Space • 3 hypothetical light sources, X, Y, and Z, which yield positive matching curves • Y: roughly corresponds to luminous efficiency characteristic of human eye CIE Color Space CIE xyY Space • Irregular 3D volume shape is difficult to understand • Chromaticity diagram (the same color of the varying intensity, Y, should all end up at the same point) Color Gamut • The range of color representation of a display device RGB (monitors) • The de facto standard The RGB Cube • RGB color space is perceptually non-linear • RGB space is a subset of the colors human can perceive • Con: what is ‘bloody red’ in RGB? CMY(K): printing • Cyan, Magenta, Yellow (Black) – CMY(K) • A subtractive color model dye color absorbs reflects cyan red blue and green magenta green blue and red yellow blue red and green black all none RGB and CMY • Converting between RGB and CMY RGB and CMY HSV • This color model is based on polar coordinates, not Cartesian coordinates. -
Chapter 6 : Color Image Processing
Chapter 6 : Color Image Processing CCU, Taiwan Wen-Nung Lie Color Fundamentals Spectrum that covers visible colors : 400 ~ 700 nm Three basic quantities Radiance : energy that flows from the light source (measured in Watts) Luminance : a measure of energy an observer perceives from a light source (in lumens) Brightness : a subjective descriptor difficult to measure CCU, Taiwan Wen-Nung Lie 6-1 About human eyes Primary colors for standardization blue : 435.8 nm, green : 546.1 nm, red : 700 nm Not all visible colors can be produced by mixing these three primaries in various intensity proportions Cones in human eyes are divided into three sensing categories 65% are sensitive to red light, 33% sensitive to green light, 2% sensitive to blue (but most sensitive) The R, G, and B colors perceived by CCU, Taiwan human eyes cover a range of spectrum Wen-Nung Lie 6-2 Primary and secondary colors of light and pigments Secondary colors of light magenta (R+B), cyan (G+B), yellow (R+G) R+G+B=white Primary colors of pigments magenta, cyan, and yellow M+C+Y=black CCU, Taiwan Wen-Nung Lie 6-3 Chromaticity Hue + saturation = chromaticity hue : an attribute associated with the dominant wavelength or dominant colors perceived by an observer saturation : relative purity or the amount of white light mixed with a hue (the degree of saturation is inversely proportional to the amount of added white light) Color = brightness + chromaticity Tristimulus values (the amount of R, G, and B needed to form any particular color : X, Y, Z trichromatic -
CDOT Shaded Color and Grayscale Printing Reference File Management
CDOT Shaded Color and Grayscale Printing This document guides you through the set-up and printing process for shaded color and grayscale Sheet Files. This workflow may be used any time the user wants to highlight specific areas for things such as phasing plans, public meetings, ROW exhibits, etc. Please note that the use of raster images (jpg, bmp, tif, ets.) will dramatically increase the processing time during printing. Reference File Management Adjustments must be made to some of the reference file settings in order to achieve the desired print quality. The settings that need to be changed are the Slot Numbers and the Update Sequence. Slot Numbers are unique identifiers assigned to reference files and can be called out individually or in groups within a pen table for special processing during printing. The Update Sequence determines the order in which files are refreshed on the screen and printed on paper. Reference file Slot Number Categories: 0 = Sheet File (black)(this is the active dgn file.) 1-99 = Proposed Primary Discipline (Black) 100-199 = Existing Topo (light gray) 200-299 = Proposed Other Discipline (dark gray) 300-399 = Color Shaded Areas Note: All data placed in the Sheet File will be printed black. Items to be printed in color should be in their own file. Create a new file using the standard CDOT seed files and reference design elements to create color areas. If printing to a black and white printer all colors will be printed grayscale. Files can still be printed using the default printer drivers and pen tables, however shaded areas will lose their transparency and may print black depending on their level. -
Cielab Color Space
Gernot Hoffmann CIELab Color Space Contents . Introduction 2 2. Formulas 4 3. Primaries and Matrices 0 4. Gamut Restrictions and Tests 5. Inverse Gamma Correction 2 6. CIE L*=50 3 7. NTSC L*=50 4 8. sRGB L*=/0/.../90/99 5 9. AdobeRGB L*=0/.../90 26 0. ProPhotoRGB L*=0/.../90 35 . 3D Views 44 2. Linear and Standard Nonlinear CIELab 47 3. Human Gamut in CIELab 48 4. Low Chromaticity 49 5. sRGB L*=50 with RGB Numbers 50 6. PostScript Kernels 5 7. Mapping CIELab to xyY 56 8. Number of Different Colors 59 9. HLS-Hue for sRGB in CIELab 60 20. References 62 1.1 Introduction CIE XYZ is an absolute color space (not device dependent). Each visible color has non-negative coordinates X,Y,Z. CIE xyY, the horseshoe diagram as shown below, is a perspective projection of XYZ coordinates onto a plane xy. The luminance is missing. CIELab is a nonlinear transformation of XYZ into coordinates L*,a*,b*. The gamut for any RGB color system is a triangle in the CIE xyY chromaticity diagram, here shown for the CIE primaries, the NTSC primaries, the Rec.709 primaries (which are also valid for sRGB and therefore for many PC monitors) and the non-physical working space ProPhotoRGB. The white points are individually defined for the color spaces. The CIELab color space was intended for equal perceptual differences for equal chan- ges in the coordinates L*,a* and b*. Color differences deltaE are defined as Euclidian distances in CIELab. This document shows color charts in CIELab for several RGB color spaces. -
Expanded Gamut Shoot-Out: Real Systems, Real Results
Expanded Gamut Shoot-Out: Real Systems, Real Results Abhay Sharma Click toRyerson edit Master University, subtitle Toronto style Advisors Roger Breton, Marc Levine, John Seymour, Bill Pope Comprehensive Report – 450+ downloads tinyurl.com/ExpandedGamut Agenda – Expanded Gamut § Why do we need Expanded Gamut? § What is Expanded Gamut? (CMYK-OGV) § Use cases – Spot Colors vs Images PANTONE 109 C § Printing Spot Colors with Kodak Spotless (KSS) § Increased Accuracy § Using only 3 inks § Print all spot colors, without spot color inks § How do I implement EG? § Issues with Adobe and Pantone § Flexo testing in 2020 Vendors and Participants Software Solutions 1. Alwan – Toolbox, ColorHub 2. CGS ORIS – X GAMUT 3. ColorLogic – ColorAnt, CoPrA, ZePrA 4. GMG Color – OpenColor, ColorServer 5. Heidelberg – Prinect ColorToolbox 6. Kodak – Kodak Spotless Software, Prinergy PDF Editor § Hybrid Software - PACKZ (pronounced “packs”) RIP/DFE § efi Fiery XF (Command WorkStation) – Epson P9000 § SmartStream Production Pro – HP Indigo 7900 Color Management Solutions § X-Rite i1Profiler Expanded Gamut Tools § PANTONE Color Manager, Adobe Acrobat Pro, Adobe Photoshop Why do we need Expanded Gamut? - because imaging systems are imperfect Printing inks and dyes CMYK color gamut is small Color negative film What are the Use Cases for Expanded Gamut? ✓ 1. Spot Colors 2. Images PANTONE 301 C PANTONE 109 C Expanded gamut is most urgently needed in spot color reproduction for labels and package printing. Orange, Green, Violet - expands the colorspace Y G O C+Y M+Y -
NEC Multisync® PA311D Wide Gamut Color Critical Display Designed for Photography and Video Production
NEC MultiSync® PA311D Wide gamut color critical display designed for photography and video production 1419058943 High resolution and incredible, predictable color accuracy. The 31” MultiSync PA311D is the ultimate desktop display for applications where precise color is essential. The innovative wide-gamut LED backlight provides 100% coverage of Adobe RGB color space and 98% coverage of DCI-P3, enabling more accurate colors to be displayed on screen. Utilizing a high performance IPS LCD panel and backed by a 4 year warranty with Advanced Exchange, the MultiSync PA311D delivers high quality, accurate images simply and beautifully. Impeccable Image Performance The wide-gamut LED LCD backlight combined with NEC’s exclusive SpectraView Engine deliver precise color in every environment. • True 4K resolution (4096 x 2160) offers a high pixel density • Up to 100% coverage of Adobe RGB color space and 98% coverage of DCI-P3 • 10-bit HDMI and DisplayPort inputs display up to 1.07 billion colors out of a palette of 4.3 trillion colors Ultimate Color Management The sophisticated SpectraView Engine provides extensive, intuitive control over color settings. • MultiProfiler software and on-screen controls provide access to thousands of color gamut, gamma, white point, brightness and contrast combinations • Internal 14-bit 3D lookup tables (LUTs) work with optional SpectraViewII color calibration solution for unparalleled color accuracy A Perfect Fit for Your Workspace A Better Workflow Future-proof connectivity, great ergonomics, and VESA mount Exclusive, -
The Art of Digital Black & White by Jeff Schewe There's Just Something
The Art of Digital Black & White By Jeff Schewe There’s just something magical about watching an image develop on a piece of photo paper in the developer tray…to see the paper go from being just a blank white piece of paper to becoming a photograph is what many photographers think of when they think of Black & White photography. That process of watching the image develop is what got me hooked on photography over 30 years ago and Black & White is where my heart really lives even though I’ve done more color work professionally. I used to have the brown stains on my fingers like any good darkroom tech, but commercially, I turned toward color photography. Later, when going digital, I basically gave up being able to ever achieve what used to be commonplace from the darkroom–until just recently. At about the same time Kodak announced it was going to stop making Black & White photo paper, Epson announced their new line of digital ink jet printers and a new ink, Ultrachrome K3 (3 Blacks- hence the K3), that has given me hope of returning to darkroom quality prints but with a digital printer instead of working in a smelly darkroom environment. Combine the new printers with the power of digital image processing in Adobe Photoshop and the capabilities of recent digital cameras and I think you’ll see a strong trend towards photographers going digital to get the best Black & White prints possible. Making the optimal Black & White print digitally is not simply a click of the shutter and push button printing. -
Accurately Reproducing Pantone Colors on Digital Presses
Accurately Reproducing Pantone Colors on Digital Presses By Anne Howard Graphic Communication Department College of Liberal Arts California Polytechnic State University June 2012 Abstract Anne Howard Graphic Communication Department, June 2012 Advisor: Dr. Xiaoying Rong The purpose of this study was to find out how accurately digital presses reproduce Pantone spot colors. The Pantone Matching System is a printing industry standard for spot colors. Because digital printing is becoming more popular, this study was intended to help designers decide on whether they should print Pantone colors on digital presses and expect to see similar colors on paper as they do on a computer monitor. This study investigated how a Xerox DocuColor 2060, Ricoh Pro C900s, and a Konica Minolta bizhub Press C8000 with default settings could print 45 Pantone colors from the Uncoated Solid color book with only the use of cyan, magenta, yellow and black toner. After creating a profile with a GRACoL target sheet, the 45 colors were printed again, measured and compared to the original Pantone Swatch book. Results from this study showed that the profile helped correct the DocuColor color output, however, the Konica Minolta and Ricoh color outputs generally produced the same as they did without the profile. The Konica Minolta and Ricoh have much newer versions of the EFI Fiery RIPs than the DocuColor so they are more likely to interpret Pantone colors the same way as when a profile is used. If printers are using newer presses, they should expect to see consistent color output of Pantone colors with or without profiles when using default settings. -
Preparing Images for Delivery
TECHNICAL PAPER Preparing Images for Delivery TABLE OF CONTENTS So, you’ve done a great job for your client. You’ve created a nice image that you both 2 How to prepare RGB files for CMYK agree meets the requirements of the layout. Now what do you do? You deliver it (so you 4 Soft proofing and gamut warning can bill it!). But, in this digital age, how you prepare an image for delivery can make or 13 Final image sizing break the final reproduction. Guess who will get the blame if the image’s reproduction is less than satisfactory? Do you even need to guess? 15 Image sharpening 19 Converting to CMYK What should photographers do to ensure that their images reproduce well in print? 21 What about providing RGB files? Take some precautions and learn the lingo so you can communicate, because a lack of crystal-clear communication is at the root of most every problem on press. 24 The proof 26 Marking your territory It should be no surprise that knowing what the client needs is a requirement of pro- 27 File formats for delivery fessional photographers. But does that mean a photographer in the digital age must become a prepress expert? Kind of—if only to know exactly what to supply your clients. 32 Check list for file delivery 32 Additional resources There are two perfectly legitimate approaches to the problem of supplying digital files for reproduction. One approach is to supply RGB files, and the other is to take responsibility for supplying CMYK files. Either approach is valid, each with positives and negatives. -
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. -
Grayscale Lithography Creating Complex 2.5D Structures in Thick Photoresist by Direct Laser Writing
EPIC Meeting on Wafer Level Optics Grayscale Lithography Creating complex 2.5D structures in thick photoresist by direct laser writing 07/11/2019 Dominique Collé - Grayscale Lithography Heidelberg Instruments in a Nutshell • A world leader in the production of innovative, high- precision maskless aligners and laser lithography systems • Extensive know-how in developing customized photolithography solutions • Providing customer support throughout system’s lifetime • Focus on high quality, high fidelity, high speed, and high precision • More than 200 employees worldwide (and growing fast) • 40 million Euros turnover in 2017 • Founded in 1984 • An installation base of over 800 systems in more than 50 countries • 35 years of experience 07/11/2019 Dominique Collé - Grayscale Lithography Principle of Grayscale Photolithography UV exposure with spatially modulated light intensity After development: the intensity gradient has been transferred into resist topography. Positive photoresist Substrate Afterward, the resist topography can be transfered to a different material: the substrate itself (etching) or a molding material (electroforming, OrmoStamp®). 07/11/2019 Dominique Collé - Grayscale Lithography Applications Microlens arrays Fresnel lenses Diffractive Optical elements • Wavefront sensor • Reduced lens volume • Modified phase profile • Fiber coupling • Mobile devices • Split & shape beam • Light homogenization • Miniature cameras • Complex light patterns 07/11/2019 Dominique Collé - Grayscale Lithography Applications Diffusers & reflectors -
Dalmatian's Definitions
T H E B L A C K & W H I T E P A P E R S D A L M A T I A N ’ S D E F I N I T I O N S 8 BIT A bit is the possible number of colors or tones assigned to each pixel. In 8 bit files, 1 of 256 tones is assigned to each pixel. 8-bit Jpeg is the default setting for most cameras; whenever possible set the camera to RAW capture for the best image capture possible. 16 BIT A bit is the possible number of colors or tones assigned to each pixel. In 16 bit files, 1 of 65,536 tones are assigned to each pixel. 16 bit files have the greatest range of tonalities and a more realistic interpretation of continuous tone. Note the increase in tonalities from 8 bit to 16 bit. If your aim is the quality of the image, then 16 bit is a must. ADOBE 1998 COLOR SPACE Adobe ‘98 is the preferred RGB color space that places the captured and therefore printable colors within larger parameters, rendering approximately 50% the visible color space of the human eye. Whenever possible, change the camera’s default sRGB setting to Adobe 1998 in order to increase available color capture. Whenever possible change this setting to Adobe 1998 in order to increase available color capture. When an image is captured in sRGB, it is best to leave the color space unchanged so color rendering is unaffected. ARCHIVAL Archival materials are those with a neutral pH balance that will not degrade over time and are resistant to UV fading.