third index in three dimention array

kindly explain me about the following line

Vt = zeros(img_h, img_w, 4);

i know the following line if(img_h=2, img_w=3)

zeros (img_h, img_w)=[0 0 0; 0 0 0]

but i cant clearly understand the third dimention

[Stephen23]

https://www.mathworks.com/help/matlab/math/multidimensional-arrays.html

Answer 1

[KSSV]

You matrices can be 1D, 2D, 3D or nD...where D stands for dimensional.

A = zeros(2,2,2) ; 

The above A has 2 matrices of size 2X2 having zeros.

B = ones(3,4,5) ; 

The above matrix has 5 matrices each os size 3*4.

I = imread("cameraman.tif") ; 
size(I)

Check the size of I above. So nD matrices are possible, in your case third dimension stands for that.

[Rd]

Thank you for your clear explanation

Answer 2

[madhan ravi]

Imagine that 2 X 3 matrix is copied 4 times.