RGB转换到XYZ是什么样子的？ （附python代码）

实际上XYZ色彩空间是通过RGB（线性信号）放射变换产生的， 即乘一个3X3 的矩阵
代码如下， 以NTSC色彩空间下的RGB举例

import numpy as np
from mpl_toolkits.mplot3d import Axes3D
from mpl_toolkits.mplot3d.art3d import Poly3DCollection, Line3DCollection
import matplotlib.pyplot as plt

points = np.array([[0, 0, 0],
                  [1, 0, 0 ],
                  [1, 1, 0],
                  [0, 1, 0],
                  [0, 0, 1],
                  [1, 0, 1 ],
                  [1, 1, 1],
                  [0, 1, 1]])

P = [[0.6068909,  0.1735011,  0.2003480],
 [0.2989164,  0.5865990,  0.1144845],
 [0.0000000,  0.0660957,  1.1162243]]

Z = np.zeros((8,3))
for i in range(8): Z[i,:] = np.dot(points[i,:],P)
Z = 1.0*Z

fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')

r = [-1,1]

X, Y = np.meshgrid(r, r)
# plot vertices
ax.scatter3D(Z[:, 0], Z[:, 1], Z[:, 2])

# list of sides' polygons of figure
verts = [[Z[0],Z[1],Z[2],Z[3]],
 [Z[4],Z[5],Z[6],Z[7]], 
 [Z[0],Z[1],Z[5],Z[4]], 
 [Z[2],Z[3],Z[7],Z[6]], 
 [Z[1],Z[2],Z[6],Z[5]],
 [Z[4],Z[7],Z[3],Z[0]]]

# plot sides
ax.add_collection3d(Poly3DCollection(verts, 
 facecolors='cyan', linewidths=1, edgecolors='black', alpha=.9))

ax.set_xlabel('X')
ax.set_ylabel('Y')
ax.set_zlabel('Z')

plt.show()