将RGB十六进制转换为R中的3d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，不幸的是我现在不怎么做。

Answer 1

让我们使用颜色“＃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