1 /////////////////////////////////////////////////////////////////////////// 2 // 3 // Copyright (c) 2003, Industrial Light & Magic, a division of Lucas 4 // Digital Ltd. LLC 5 // 6 // All rights reserved. 7 // 8 // Redistribution and use in source and binary forms, with or without 9 // modification, are permitted provided that the following conditions are 10 // met: 11 // * Redistributions of source code must retain the above copyright 12 // notice, this list of conditions and the following disclaimer. 13 // * Redistributions in binary form must reproduce the above 14 // copyright notice, this list of conditions and the following disclaimer 15 // in the documentation and/or other materials provided with the 16 // distribution. 17 // * Neither the name of Industrial Light & Magic nor the names of 18 // its contributors may be used to endorse or promote products derived 19 // from this software without specific prior written permission. 20 // 21 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 24 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 25 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 26 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 27 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 31 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 // 33 /////////////////////////////////////////////////////////////////////////// 34 35 36 #ifndef INCLUDED_IMF_CHROMATICITIES_H 37 #define INCLUDED_IMF_CHROMATICITIES_H 38 39 //----------------------------------------------------------------------------- 40 // 41 // CIE (x,y) chromaticities, and conversions between 42 // RGB tiples and CIE XYZ tristimulus values. 43 // 44 //----------------------------------------------------------------------------- 45 46 #include "ImathVec.h" 47 #include "ImathMatrix.h" 48 #include "ImfNamespace.h" 49 #include "ImfExport.h" 50 51 52 OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_ENTER 53 54 55 struct IMF_EXPORT Chromaticities 56 { 57 //----------------------------------------------- 58 // The CIE x and y coordinates of the RGB triples 59 // (1,0,0), (0,1,0), (0,0,1) and (1,1,1). 60 //----------------------------------------------- 61 62 IMATH_NAMESPACE::V2f red; 63 IMATH_NAMESPACE::V2f green; 64 IMATH_NAMESPACE::V2f blue; 65 IMATH_NAMESPACE::V2f white; 66 67 //-------------------------------------------- 68 // Default constructor produces chromaticities 69 // according to Rec. ITU-R BT.709-3 70 //-------------------------------------------- 71 72 Chromaticities (const IMATH_NAMESPACE::V2f &red = IMATH_NAMESPACE::V2f (0.6400f, 0.3300f), 73 const IMATH_NAMESPACE::V2f &green = IMATH_NAMESPACE::V2f (0.3000f, 0.6000f), 74 const IMATH_NAMESPACE::V2f &blue = IMATH_NAMESPACE::V2f (0.1500f, 0.0600f), 75 const IMATH_NAMESPACE::V2f &white = IMATH_NAMESPACE::V2f (0.3127f, 0.3290f)); 76 77 78 //--------- 79 // Equality 80 //--------- 81 82 bool operator == (const Chromaticities &v) const; 83 bool operator != (const Chromaticities &v) const; 84 }; 85 86 87 // 88 // Conversions between RGB and CIE XYZ 89 // 90 // RGB to XYZ: 91 // 92 // Given a set of chromaticities, c, and the luminance, Y, of the RGB 93 // triple (1,1,1), or "white", RGBtoXYZ(c,Y) computes a matrix, M, so 94 // that multiplying an RGB value, v, with M produces an equivalent 95 // XYZ value, w. (w == v * M) 96 // 97 // If we define that 98 // 99 // (Xr, Yr, Zr) == (1, 0, 0) * M 100 // (Xg, Yg, Zg) == (0, 1, 0) * M 101 // (Xb, Yb, Zb) == (0, 0, 1) * M 102 // (Xw, Yw, Zw) == (1, 1, 1) * M, 103 // 104 // then the following statements are true: 105 // 106 // Xr / (Xr + Yr + Zr) == c.red.x 107 // Yr / (Xr + Yr + Zr) == c.red.y 108 // 109 // Xg / (Xg + Yg + Zg) == c.red.x 110 // Yg / (Xg + Yg + Zg) == c.red.y 111 // 112 // Xb / (Xb + Yb + Zb) == c.red.x 113 // Yb / (Xb + Yb + Zb) == c.red.y 114 // 115 // Xw / (Xw + Yw + Zw) == c.red.x 116 // Yw / (Xw + Yw + Zw) == c.red.y 117 // 118 // Yw == Y. 119 // 120 // XYZ to RGB: 121 // 122 // YYZtoRGB(c,Y) returns RGBtoXYZ(c,Y).inverse(). 123 // 124 125 IMF_EXPORT IMATH_NAMESPACE::M44f RGBtoXYZ (const Chromaticities chroma, float Y); 126 IMF_EXPORT IMATH_NAMESPACE::M44f XYZtoRGB (const Chromaticities chroma, float Y); 127 128 129 OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_EXIT 130 131 #endif 132