https://blog.csdn.net/lxw907304340/article/details/45641419#comments_15463002
https://blog.csdn.net/lxw907304340/article/details/45641675#comments_13292433
https://blog.csdn.net/lxw907304340/article/details/45641675】
Color math and programming code examples
These are the formulas used by our Color Calculator to convert color data in different color spaces.
Each conversion formula is written as a "neutral programming function", easy to be translate in any specific programming language:
//X, Y and Z input refer to a D65/2° standard illuminant. //sR, sG and sB (standard RGB) output range = 0 ÷ 255 var_X = X / 100 var_Y = Y / 100 var_Z = Z / 100 var_R = var_X * 3.2406 + var_Y * -1.5372 + var_Z * -0.4986 var_G = var_X * -0.9689 + var_Y * 1.8758 + var_Z * 0.0415 var_B = var_X * 0.0557 + var_Y * -0.2040 + var_Z * 1.0570 if ( var_R > 0.0031308 ) var_R = 1.055 * ( var_R ^ ( 1 / 2.4 ) ) - 0.055 else var_R = 12.92 * var_R if ( var_G > 0.0031308 ) var_G = 1.055 * ( var_G ^ ( 1 / 2.4 ) ) - 0.055 else var_G = 12.92 * var_G if ( var_B > 0.0031308 ) var_B = 1.055 * ( var_B ^ ( 1 / 2.4 ) ) - 0.055 else var_B = 12.92 * var_B sR = var_R * 255 sG = var_G * 255 sB = var_B * 255
clc; close all; clear all; rgb = imread('lena.bmp'); subplot(2,3,1),imshow(rgb,'InitialMagnification','fit');title('原图像'); rgb =double(rgb);%双精度化(0-255) x = 0.607*rgb(:,:,1)+0.174*rgb(:,:,2)+0.201*rgb(:,:,3); x = mat2gray(x);%把矩阵转化为灰度图像 y = 0.299*rgb(:,:,1)+0.587*rgb(:,:,2)+0.114*rgb(:,:,3); y = mat2gray(y); z = 0.066*rgb(:,:,2)+0.117*rgb(:,:,3); z = mat2gray(z); xyz = cat(3,x,y,z);%把x,y,z连在一起 subplot(2,3,3),imshow(xyz);title('XYZ图像'); subplot(2,3,4),imshow(x);title('X图像'); subplot(2,3,5),imshow(y);title('Y图像'); subplot(2,3,6),imshow(z);title('Z图像');
运行结果:
注:Matlab中没有lena.bmp文件,可以从网上下载,此外imshow(rgb,'notruesize')在Matlab2012中不在支持应改为 imshow(rgb,'InitialMagnification','fit')。