如何将图像从 RGB 域转换为 YST 域？

Question

I am a newbie to the YST domain area. I want to convert an RGB 32x32 pixel image into the YST color domain of the same size. After reading some research papers I got the formula for conversion but not sure how to go about it using python.

Answer 1

You can define the conversion as a matrix and multiply it using matrix multiplication:

import numpy as np

x = [[0.299, 0.587, 0.114],[0.147, -0.289, 0.436],[0.615, -0.515, -0.1]]

rgb = [1,2,3]

x = np.matrix(x)

yst = x.dot(rgb)

EDIT:

To convert your complete image you would have to do:

test_img=np.ones((32,32,3))

x = [[0.299, 0.587, 0.114],[0.147, -0.289, 0.436],[0.615, -0.515, -0.1]]
x = np.array(x)

yst_img = []
for i in range(len(test_img)):
    yst_img.append([])
    for rgb in test_img[i]:
        yst_img[i].append(x.dot(rgb))

 yst_img = np.array(yst_img) #in case you want your data as an array

Answer 2

Using numpy you can

• build the matrix .array()
• multiply it by a vector .dot(vector)

import numpy as np

x = [[0.299, 0.587, 0.114],[0.147, -0.289, 0.436],[0.615, -0.515, -0.1]]
x = np.array(x)

rgb = [155, 23, 49]
yst = x.dot(rgb)