在R中将RGB十六进制转换为三维矩阵

Question

我有一个RGB图像，任何单元格都是像“#FFFFFF”这样的特征值。 我想将这种格式转换为3D矩阵，并将其用于图像处理，不幸的是，我现在不会那么做。

Answer 1

让我们用颜色 “＃8A2BE2”：

# Create a 4x4 matrix with the same color 
hex <- matrix(rep("#8A2BE2", 16), 4, 4) 
hex 
#  [,1]  [,2]  [,3]  [,4]  
# [1,] "#8A2BE2" "#8A2BE2" "#8A2BE2" "#8A2BE2" 
# [2,] "#8A2BE2" "#8A2BE2" "#8A2BE2" "#8A2BE2" 
# [3,] "#8A2BE2" "#8A2BE2" "#8A2BE2" "#8A2BE2" 
# [4,] "#8A2BE2" "#8A2BE2" "#8A2BE2" "#8A2BE2" 

rgbs <- col2rgb(hex) 
# First 5 columns 
#  [,1] [,2] [,3] [,4] [,5] 
# red 138 138 138 138 138 
# green 43 43 43 43 43 
# blue 226 226 226 226 226 

rgbs <- array(t(rgbs), c(4,4,3)) 
dim(rgbs) 
# we get a 4x4x3 array 
# [1] 4 4 3 

rgbs[1:2,1:2,] 
# First 2 lines and first 2 columns 
# , , 1 
# 
#  [,1] [,2] 
# [1,] 138 138 
# [2,] 138 138 
# 
# , , 2 
# 
#  [,1] [,2] 
# [1,] 43 43 
# [2,] 43 43 
# 
# , , 3 
# 
#  [,1] [,2] 
# [1,] 226 226 
# [2,] 226 226