How to reshape an Array in c#

Question

I have a 3D array of bytes in c# which I have read from a bitmap:

byte[w, h, 3]

What is the easiest and more performance-friendly way of reshaping this array into 2D (linear) form?

byte[w*h, 3]

In other words I want to keep number of channels (features) but in a linear shape (rather than a square shape)

Let me try to illustrate input and desired output:

input:

|(r1,g1,b1)    (r2,g2,b2)    (r3,g3,b3)|
|(r4,g4,b4)    (r5,g5,b5)    (r6,g6,b6)|
|(r7,g7,b7)    (r8,g8,b8)    (r9,g9,b9)|

note that arr[0, 0, 0] = r1, arr[0, 0, 1] = g1, arr[0, 0, 2] = b1, etc..

and output:

|(r1,g1,b1)    (r2,g2,b2)    (r3,g3,b3)    (r4,g4,b4)    (r5,g5,b5)    (r6,g6,b6) ...|

user_3715778 · Answer

As an alternative you might want to use System.Numerics.Tensors:

It makes reshaping very easy:

using System.Numerics.Tensors;
..
var src = new byte[3, w, h]
var dst = ArrayTensorExtensions
    .ToTensor(src)
    .Reshape(new[] { 3, w * h });