How to use the size of a matrix while coding

Hello there,

I am trying to representing a 2D image in 3D, " representing matrix with the RGB value as a z-axis while keeping the x- and y-axes".

I am woriking on the following code, but i have a problem while using the dimentions of the image.

let say [X,Y,D] = size(image);

how to use the X and Y inside my following code, i wrote something related to C, can someone help me make matlab accept the syntax?

rgb_image=imread('animalCell.jpg');
% Converting image format and getting colormap
[C,map] = rgb2ind(rgbim,32);
% Setting X,Y dimensions, where X and Y has the same dimensions.
[X,Y] = meshgrid(-floor(size(rgbim, 2)/2):floor(size(rgbim, 2)/2)-1, -floor(size(rgbim, 1)/2):floor(size(rgbim, 1)/2)-1);
 
% Dimensions X and Y must be the same as C. This can be accomplished by adjusting the meshgrid. Automatically done below.
i = 0;
j = 0;
while ( size{X}{1} ~= size{C}{1} ) % While dimensions of x different for X and C, Note X == Y.
   i=i+1;
   [X,Y] = meshgrid(-floor(size(rgbim, 2)/2):floor(size(rgbim, 2)/2) + 10 - j, -floor(size(rgbim, 1)/2):floor(size(rgbim, 1)/2) + 10 - i);
end
 
while ( size{X}{2} ~= size{C}{2} ) % While dimensions of x different for X and C, Note X == Y.
   j=j+1;
   [X,Y] = meshgrid(-floor(size(rgbim, 2)/2):floor(size(rgbim, 2)/2) + 10 - j, -floor(size(rgbim, 1)/2):floor(size(rgbim, 1)/2) + 10 - i);
end
 
% If error persists, print array dimensions of X, Y, and C
XC = isequal(size(X),size(C));
YC = isequal(size(Y),size(C));
if XC ~= 1 || YC ~= 1
   fprintf('size(X):   %i   %i\n', size{X}{1}, size{X}{2});
   fprintf('size(Y):   %i   %i\n', size{Y}{1}, size{Y}{2});
   fprintf('size(C):   %i   %i\n', size{C}{1}, size{C}{2});
end
 
% Setting a reasonable restriction on the Z (C) axis, which in turn enables the exportation of a reasonable 3D object
k = max(C(:)) / max(X(:));
[Z] = double(C/k);
 
% Setting 3D figure output
figure;
surf(X, Y, Z, double(C)), shading flat;
colormap(map); % This command returns the original image colour

I am getting the error, Undefined variable "size" or class "size".

[dpb]

What does

which -all size

return? Try

clear size

and retry..

But, you read in the image to the variable rgb_image but then use rgbim which isn't defined.

Also, you compute the size() of the same thing over and over...why not use

[nr,nc]=size(rgb_image);

and then use nr,nc where needed instead? Much easier code to read that way even if the JIT optimizer can avoid redoing the call every time...