DOCSLIB.ORG

Cielab Color Space

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

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. .0 y sRGB uses ITU-R BT.709 primaries 0.9 Red Green Blue White ProPhoto x 0.64 0.30 0.5 0.327 520 525 y 0.33 0.60 0.06 0.3290 0.8 55 530 535 AdobeRGB uses Red and Blue like 50 540 sRGB and Green like NTSC 545 CIE-RGB are the primaries for color 0.7 550 matching tests: 700/546./435.8nm 505 555 560 0.6 565 570 500 575 NTSC CIE sRGB 0.5 580 585 590 495 0.4 595 600 605 60 0.3 620 490 635 700 Wavelengths in nm 0.2 485 480 Purple line 0. 475 470 460 0.0 380 0.0 0. 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 x .0 2 1.2 Introduction CIELab uses new coordinates L*,a* and b* by functions as described in the next chap- ter. The true shape of the human gamut in CIELab is shown in chapter 13. This results in huge areas for higher luminance. Just to show the orientation together with the gamut triangle for the primaries we pro- ceed as follows: Convert the contour points x,y for Y= into RGB. Divide R,G,B by the maximum of R,G,B. Convert R,G,B to L*,a*,b*. The gamut triangle in xyY has to be replaced by a representation of a color cube with corners R,G,B and Y(yellow),C,M. The gray axis is at a*=b*=0. Therefore the area is confined by a distorted hexagon. A similar diagram can be found in []. Later it will be shown that the actual gamut, which depends on the luminance, is a smaller area inside the hexagon. -250 -225 -200 -75 -50 -25 -00 -75 -50 -25 0 25 50 75 00 25 50 75 200 225 250 b* 250 225 225 200 200 75 75 Green 50 50 25 25 00 00 Red 75 75 50 50 25 25 0 0 -25 -25 -50 -50 -75 -75 -00 Gamut -00 -25 CIE primaries -25 WP Eq.Energy -50 -50 Blue -75 Contour for -75 R-Y-G-C-B-M-R -200 hexagon -200 Outer blue area -225 -225 human gamut -250 -250 -250 -225 -200 -75 -50 -25 -00 -75 -50 -25 0 25 50 75 00 25 50 75 200 225 a* 3 2.1 Formulas / From RGB’ to CIELab R´G´B´ are nonlinearly distorted values for each channel in physical tristimulus systems like CIE, NTSC or working spaces like sRGB or AdobeRGB(98). RGB are undistorted values which are linearly related to CIEXYZ. Each RGB system has a white point(w). The transformation to CIELab requires a re- ference white point (n) which is either (w) or D50. Issues of adaptation are taken into account by the linearized Bradford transform. The Bradford matrix maps the XYZ-values for a color in e.g. D65 to another set in D50. The colors should look alike under D65 for the first set and under D50 for the second. Generic gamma correction, G=2.2, C=R,G,B CC= 'G sRGB gamma correction, C=R,G,B C'/2.92 if C'≤ 0.03928 C = 2.4 ((0.055+ C')/.055) else RGB to XYZ (same white point D65) XCR= xr RGB to XYZ (new white point D50, Bradford correction) XBCR= xr XYZ to L*a*b* (reference white Xn ) X X = Xn Y Y = Yn Z Z = Zn 3 X if X > 0.008856 X = 7.787 X+ 6 6 else 3 Y if Y > 0.008856 Y = 7.787 Y+ 6 6 else 3 Z if Z > 0.008856 Z = 7.787Z+ 66 else L*= 6 Y − 6 a*= 500 ( X − Y ) b*= 200 ( Y − Z ) 4 2.2 Formulas / From CIELab to RGB’ Please refer to explanations on the previous page. A value RGB is out of gamut if any of the numbers is less than 0 or greater than 1 (normalized values). L*a*b* to XYZ Y = (L* + 6)/6 X = a* / 500 + Y Z = − b*/ 200 + Y 3 X if X > 0.206893 X = (X − 6 6) / 7.787 else 3 Y if Y > 0.206893 Y = (Y − 6 6) / 7.787 else 3 Z if Z > 0.206893 Z = (Z − 6 6) / 7.787 else XXX= n YYY= n Z = ZZn XYZ to RGB (same white point D50) − RCXCX=rx = xr XYZ to RGB (new white point D65, Bradford correction) − − RBCXCBX= ()xr = rx Generic gamma correction, G = 2.2, C = R,G,B CC' = / G sRGB gamma correction, C= R,G,B 2.92C if C≤ 0.00304 C' = 2.4 .055C− 0.055 else 5 2.3 Formulas / From xyY to XYZ The CIE chromaticity diagram is called xyY.The threedimensional space is called XYZ. xyY to XYZ z= − x − y X= Y x / y Z= Y z / y XYZ to xyY DXYZ= + + x= X / D y= Y / D z= Z / D Some important numbers 3 0.008856= 0.2068930 6/6= 0.3793 6⋅ 0.008856 3 − 6 = 903.3 ⋅ 0.008856 = 8.0 6 2.4 Formulas / Structure of the Conversion The conversion from XYZ to L*a*b* consists essentially of four steps: . White point correction 2. Nonlinear distortion of the variables X,Y,Z by a cubic root 3. Linear transformation into a new vector basis c, a, b 4. Scaling With some obvious simplifications the linear part can be written by matrices: X 0 L Y = 0 0 A Z 0− B X 0 Y=LA0B0 + + = Lc + A a + B b Z 0 − L 0 0 X A = − 0 Y B 0 − Z Z c Y X,a b Base vector a points into X-direction, b into negative Z-direction and c is along the diagonal in XYZ. L, A and B are normalized substitutes for L*, a* and b*. 7 2.5 Formulas / Matrix Calculation Matrices for Primaries and White Point [3] XR YG = Cxr ZB RX GY = Crx BZ D= (xr − x)(y b g − y)(y b − r − y)(x b g − x) b U= (xw − x)(y b g − y)(y b − w − y)(x b g − x) b V= (xr − x)(y b w − y)(y b − r − y)(x b w − x) b u= U / D v= V / D w= − u − v ux/yr w vx/y g w wx/y b w C = uy/y vy/y wy/ y xr r w g w b w uz/yr w vz/y g w wz/y b w − CCrx= xr In the next formulas use cxrik for c ik D= c(cc 22 33− cc)c(cc 23 32 − 2 233− cc)c(cc 23 3 + 3 232− cc) 22 3 crx= ( c 22 c 33 − c 23 c 32 ) / D crx2= ( c 2 c 33 − c 3 c 32 ) / D crx3= ( c 2 c 23 − c 3 c 22 ) /D crx2= ( c 2 c 33 − c 23 c 3 ) / D crx22= ( c c 33 − c 3 c 3 ) / D crx23= ( c c 23 − c 3 c 2 ) / D crx3= ( c 2 c 32 − c 22 c 3 ) / D crx32= ( c c 32 − c 2 c 3 ) / D crx33= ( c c 22 − c 2 c 2 ) / D 8 2.6 Formulas / Bradford Matrix Calculation Bradford matrix calculation, based on [8] zn = − xn − y n Yn = Xn= Y n x n / y n Zn= Y n z n / y n zw = − xw − y w Yw = Xw= Y w x w / y w Zw= Y w z w / y w Cone response +0.895 + 0.2664 − 0.64 Mcx = −0.7502 + .735 + 0.0367 +0.0389 − 0.0685 + .0296 ρn Cn= γ n = MX cx n βn ρw Cw= γ w = M cx X w βw ρn/ ρ w 0 0 D = 0γn / γ w 0 0 0βn / β w Bradford matrix − BMDM= cx cx TheE.g.
Recommended publications
  • COLOR SPACE MODELS for VIDEO and CHROMA SUBSAMPLING

    COLOR SPACE MODELS for VIDEO and CHROMA SUBSAMPLING

    COLOR SPACE MODELS for VIDEO and CHROMA SUBSAMPLING Color space A color model is an abstract mathematical model describing the way colors can be represented as tuples of numbers, typically as three or four values or color components (e.g. RGB and CMYK are color models). However, a color model with no associated mapping function to an absolute color space is a more or less arbitrary color system with little connection to the requirements of any given application. Adding a certain mapping function between the color model and a certain reference color space results in a definite "footprint" within the reference color space. This "footprint" is known as a gamut, and, in combination with the color model, defines a new color space. For example, Adobe RGB and sRGB are two different absolute color spaces, both based on the RGB model. In the most generic sense of the definition above, color spaces can be defined without the use of a color model. These spaces, such as Pantone, are in effect a given set of names or numbers which are defined by the existence of a corresponding set of physical color swatches. This article focuses on the mathematical model concept. Understanding the concept Most people have heard that a wide range of colors can be created by the primary colors red, blue, and yellow, if working with paints. Those colors then define a color space. We can specify the amount of red color as the X axis, the amount of blue as the Y axis, and the amount of yellow as the Z axis, giving us a three-dimensional space, wherein every possible color has a unique position.
  • Harlequin RIP OEM Manual

    Harlequin RIP OEM Manual

    0RIPMate for Windows operating systems Harlequin PLUS Server RIP v9.0 June 2011 AG12325 Rev. 13 Copyright and Trademarks Harlequin PLUS Server RIP June 2011 Part number: HK‚9.0‚ÄìOEM‚ÄìWIN Document issue: 106 Copyright ¬© 2011 Global Graphics Software Ltd. All rights reserved. Certificate of Computer Registration of Computer Software. Registration No. 2006SR05517 No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, elec- tronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of Global Graphics Software Ltd. The information in this publication is provided for information only and is subject to change without notice. Global Graphics Software Ltd and its affiliates assume no responsibility or liability for any loss or damage that may arise from the use of any information in this publication. The software described in this book is furnished under license and may only be used or cop- ied in accordance with the terms of that license. Harlequin is a registered trademark of Global Graphics Software Ltd. The Global Graphics Software logo, the Harlequin at Heart Logo, Cortex, Harlequin RIP, Harlequin ColorPro, EasyTrap, FireWorks, FlatOut, Harlequin Color Management System (HCMS), Harlequin Color Production Solutions (HCPS), Harlequin Color Proofing (HCP), Harlequin Error Diffusion Screening Plugin 1-bit (HEDS1), Harlequin Error Diffusion Screening Plugin 2-bit (HEDS2), Harlequin Full Color System (HFCS), Harlequin ICC Profile Processor (HIPP), Harlequin Standard Color System (HSCS), Harlequin Chain Screening (HCS), Harlequin Display List Technology (HDLT), Harlequin Dispersed Screening (HDS), Harlequin Micro Screening (HMS), Harlequin Precision Screening (HPS), HQcrypt, Harlequin Screening Library (HSL), ProofReady, Scalable Open Architecture (SOAR), SetGold, SetGoldPro, TrapMaster, TrapWorks, TrapPro, TrapProLite, Harlequin RIP Eclipse Release and Harlequin RIP Genesis Release are all trademarks of Global Graphics Software Ltd.
  • 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

    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,
  • Preparing Images for Delivery

    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.
  • Unbounded Color Engines

    Unbounded Color Engines

    Unbounded Color Engines Marti Maria; Little CMS; Palamós; Catalonia, Spain Abstract the spec, ICC profiles are no longer limited to 8 or 16 bit, but to A Color Matching Method (CMM), also called a Color the broad range of 32-bit IEEE 754 floating point. That was a huge Engine, is a software component that does the color conversion improvement when regarding precision and dynamic range, which calculations from one device's color space to another. This paper is now only limited by floating point representation and can take as 39 discuses a new working mode for CMMs that allows such software much as 10 components to operate in a way that is not restricted by the gamut of the device encoding, the gamut of the profile connection space or any intermediate step. This allows ICC profiles to be used in new ways for a variety of applications. An open source CMM implementing this mode is also introduced. Background One of the main components of a color management system is the Color Matching Method, (CMM), which is the software engine in charge of controlling the color transformations that take place inside the system. By today, the vast majority of color management Figure 2. KODAK VISION2 500T Color Negative Film 5218 / 7218 systems do use International Color Consortium (ICC) profiles. This addendum, however, introduced another improvement ICC color management is based on device characterization perhaps not so evident but equally important. Floating point profiles. Color transformations can be obtained by linking those encoding has a huge domain, which is nearly infinite, much larger profiles.
  • Evaluating Gamut Coverage Metrics for ICC Color Profiles

    Evaluating Gamut Coverage Metrics for ICC Color Profiles

    International Journal of Chaotic Computing (IJCC), Volume 4, Issue 2, December 2016 Evaluating Gamut Coverage Metrics for ICC Color Profiles Radu Velea1, Noel Gordon2 1Technical Military Academy of Bucharest, Romania 2Google Inc Abstract The color handling characteristics of computer the input media. The objective is to maintain color monitors and other display devices can significantly accuracy across heterogeneous displays. alter the way an image is perceived by the human eye. Modern cameras and software applications can create vibrant color scenes, and can specify the color range (or gamut) of the scene with an embedded ICC profile [1]. During presentation, differences in the color gamut of the image and the display device require color management to help preserve the color Figure 1. ICC v2 color profile transform. fidelity of the image when shown on different displays. Measurements of the color characteristics However, since gamut is a physical device of display devices is thus a topic of interest. This property, if an input color can not be physically paper evaluates the ability of gamut measures, reproduced by the destination gamut, unavoidable including those commonly used in industry, to color distortion results [2], which may be perceived classify display gamuts using a user-contributed by users. It is therefore important to know (a priori, dataset of ICC display color profiles, and if possible) the end-user viewing conditions in which recommends the use of relative metrics for gamut the input media will be displayed. comparison tasks. Motivation- Gamut classification of display 1. Introduction profiles can yield valuable information on the way color is perceived in end-user systems.
  • Dalmatian's Definitions

    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.
  • Specification of Srgb

    Specification of Srgb

    How to interpret the sRGB color space (specified in IEC 61966-2-1) for ICC profiles A. Key sRGB color space specifications (see IEC 61966-2-1 https://webstore.iec.ch/publication/6168 for more information). 1. Chromaticity co-ordinates of primaries: R: x = 0.64, y = 0.33, z = 0.03; G: x = 0.30, y = 0.60, z = 0.10; B: x = 0.15, y = 0.06, z = 0.79. Note: These are defined in ITU-R BT.709 (the television standard for HDTV capture). 2. Reference display‘Gamma’: Approximately 2.2 (see precise specification of color component transfer function below). 3. Reference display white point chromaticity: x = 0.3127, y = 0.3290, z = 0.3583 (equivalent to the chromaticity of CIE Illuminant D65). 4. Reference display white point luminance: 80 cd/m2 (includes veiling glare). Note: The reference display white point tristimulus values are: Xabs = 76.04, Yabs = 80, Zabs = 87.12. 5. Reference veiling glare luminance: 0.2 cd/m2 (this is the reference viewer-observed black point luminance). Note: The reference viewer-observed black point tristimulus values are assumed to be: Xabs = 0.1901, Yabs = 0.2, Zabs = 0.2178. These values are not specified in IEC 61966-2-1, and are an additional interpretation provided in this document. 6. Tristimulus value normalization: The CIE 1931 XYZ values are scaled from 0.0 to 1.0. Note: The following scaling equations can be used. These equations are not provided in IEC 61966-2-1, and are an additional interpretation provided in this document. 76.04 X abs 0.1901 XN = = 0.0125313 (Xabs – 0.1901) 80 76.04 0.1901 Yabs 0.2 YN = = 0.0125313 (Yabs – 0.2) 80 0.2 87.12 Zabs 0.2178 ZN = = 0.0125313 (Zabs – 0.2178) 80 87.12 0.2178 7.
  • Computational RYB Color Model and Its Applications

    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.
  • Psychovisual Evaluation of the Effect of Color Spaces and Color Quantification in Jpeg2000 Image Compression

    Psychovisual Evaluation of the Effect of Color Spaces and Color Quantification in Jpeg2000 Image Compression

    PSYCHOVISUAL EVALUATION OF THE EFFECT OF COLOR SPACES AND COLOR QUANTIFICATION IN JPEG2000 IMAGE COMPRESSION Mohamed-Chaker Larabi, Christine Fernandez-Maloigne and Noel¨ Richard IRCOM-SIC Laboratory, University of Poitiers BP 30170 - 86962 Futuroscope cedex FRANCE Email : [email protected] ABSTRACT 4]. Figure 1 shows the fundamental building blocks of a typical JPEG2000 is an emerging standard for still image compres- JPEG2000 encoder as described by Rabbani[4]. sion. It is not only intended to provide rate-distortion and subjective image quality performance superior to existing standards, but also to provide features and additional func- tionalities that current standards can not address sufficiently such as lossless and lossy compression, progressive trans- mission by pixel accuracy and by resolution, etc. Currently the JPEG2000 standard is set up for use with the sRGB three-component color space.the aim of this research is to Fig. 1. JPEG2000 fundamental building blocks. determine thanks to psychovisual experiences whether or Color management in JPEG2000 was an important topic in not the color space selected will significantly improve the the development of the standard and the issue of present- image compression. The RGB, XYZ, CIELAB, CIELUV, ing color properly is becoming more and more important as YIQ, YCrCb and YUV color spaces were examined and com- systems get better and as a wider range of systems are doing pared. In addition, we started a psychovisual evaluation similar things. In the past, color has been targeted as an area on the effect of color quantification on JPEG2000 image of least concern with the overall presentation.
  • HD-SDI, HDMI, and Tempus Fugit

    HD-SDI, HDMI, and Tempus Fugit

    TECHNICALL Y SPEAKING... By Steve Somers, Vice President of Engineering HD-SDI, HDMI, and Tempus Fugit D-SDI (high definition serial digital interface) and HDMI (high definition multimedia interface) Hversion 1.3 are receiving considerable attention these days. “These days” really moved ahead rapidly now that I recall writing in this column on HD-SDI just one year ago. And, exactly two years ago the topic was DVI and HDMI. To be predictably trite, it seems like just yesterday. As with all things digital, there is much change and much to talk about. HD-SDI Redux difference channels suffice with one-half 372M spreads out the image information The HD-SDI is the 1.5 Gbps backbone the sample rate at 37.125 MHz, the ‘2s’ between the two channels to distribute of uncompressed high definition video in 4:2:2. This format is sufficient for high the data payload. Odd-numbered lines conveyance within the professional HD definition television. But, its robustness map to link A and even-numbered lines production environment. It’s been around and simplicity is pressing it into the higher map to link B. Table 1 indicates the since about 1996 and is quite literally the bandwidth demands of digital cinema and organization of 4:2:2, 4:4:4, and 4:4:4:4 savior of high definition interfacing and other uses like 12-bit, 4096 level signal data with respect to the available frame delivery at modest cost over medium-haul formats, refresh rates above 30 frames per rates. distances using RG-6 style video coax.
  • How to Use the Engine in Your Applications 2.12

    How to Use the Engine in Your Applications 2.12

    How to use the engine in your applications 2.12 https://www.littlecms.com Copyright © 2020 Marti Maria Saguer, all rights reserved. Introduction 2 Table of Contents Introduction ........................................................................................................................ 4 Documentation ............................................................................................................... 5 Requeriments ................................................................................................................. 6 Include files .................................................................................................................... 6 Basic Concepts .............................................................................................................. 7 Source code conventions ............................................................................................... 7 The const keyword ......................................................................................................... 7 The register keyword ...................................................................................................... 7 Basic Types.................................................................................................................... 8 Step-by-step Example ........................................................................................................ 9 Open the profiles .........................................................................................................