如何将标签矩阵转换为颜色矩阵以进行图像分割？

Question

例如，我有一个 256*256 的标签矩阵。班级是0-11所以12班。我想将标签矩阵转换为颜色矩阵。我尝试在这样的代码中做到这一点

`for i in range(256):
    for j in range(256):
        if x[i][j] == 11:
            dummy[i][j] = [255,255,255]
        if x[i][j] == 1:
            dummy[i][j] = [144,0,0]
        if x[i][j] == 2:
            dummy[i][j] = [0,255,0]    
        if x[i][j] == 3:
            dummy[i][j] = [0,0,255]
        if x[i][j] == 4:
            dummy[i][j] = [144,255,0]
        if x[i][j] == 5:
            dummy[i][j] = [144,0,255]            
        if x[i][j] == 6:
            dummy[i][j] = [0,255,255]
        if x[i][j] == 7:
            dummy[i][j] = [122,0,0]
        if x[i][j] == 8:
            dummy[i][j] = [0,122,0]
        if x[i][j] == 9:
            dummy[i][j] = [0,0,122]
        if x[i][j] == 10:
            dummy[i][j] = [122,0,122]
        if x[i][j] == 11:
            dummy[i][j] = [122,122,0]
            `

这是非常低效的。 PS：x的形状是[256 256]，dummy是[256 256 3]。有没有更好的办法？

Answer 1

您正在查看索引 RGB 图像 - 一个 RGB 图像，其中您有一个固定的颜色“托盘”，每个像素索引到托盘的一种颜色。请参阅this page 了解更多信息。

from PIL import Image

img = Image.fromarray(x, mode="P")
img.putpalette([
    255, 255, 255,   # index 0
    144, 0, 0, # index 1 
    0, 255, 0, # index 2 
    0, 0, 255, # index 3 
    # ... and so on, you can take it from here.
])
img.show()