获取 3d numpy 数组中的每一列

Question

I converted an image from RBG to CieLab, now I need to use the value of the cielab to calculate some equations. I have been trying to get the value of each column in the array. For example if I have:

List =

   [[[ 65 234 169]
     [203 191 245]
     [ 36  58 196]
     [207 208 143]
     [251 208 187]]

    [[ 79  69 237]
     [ 13 124  42]
     [104 165  82]
     [170 178 178]
     [ 66  42 210]]

   [[ 40 163 219]
    [142  37 140]
    [ 75 205 143]
    [246  30 221]
    [ 16  98 102]]]

How can I get it to give me the values of each columns like:

1st_column =

         65
         203
         36
         207
         251

         79
         13
         104
         170
         66
         
         40
         142
         75
         246
         16

Thank you.

Answer 1

Try:

>>> m[:, :, 0]
array([[ 65, 203,  36, 207, 251],
       [ 79,  13, 104, 170,  66],
       [ 40, 142,  75, 246,  16]])

As suggested by @mozway, you can use the ellipsis syntax: m[..., 0] .

To know more, read How do you use the ellipsis slicing syntax in Python?

You can also flatten your array:

>>> m[:, :, 0].flatten()
array([ 65, 203,  36, 207, 251,  79,  13, 104, 170,  66,  40, 142,  75, 246,  16])