How to correct error using RESHAPE

I am trying to use the reshape function in my code, however, I keep getting a reshape error

RMphantom = imresize(whatisit,[128 128]); % Rescaled

% Set the parameters for the RM phantom.
N = 64;                     % The image is N-times-N.
theta = 3:3:180;            % No. of used angles.
k_art = 20;                 % No. of iterations.
k_sirt = 20;                % No. of iterations.
x = RMphantom;
b = radon(RMphantom,theta)/255;
ntheta = length(theta);
p = length(b)/ntheta;

X = reshape(x,N,N);
Error using reshape
To RESHAPE the number of elements must not change

How would I correct this reshape error? Workspace file is also attached.

Answer 1

[Steven Lord]

Let's look at the relevant bits of your code, shall we?

%{
RMphantom = imresize(whatisit,[128 128]); % Rescaled
% Set the parameters for the RM phantom.
N = 64;                     % The image is N-times-N.
x = RMphantom;
X = reshape(x,N,N);
%}

For your reshape call to make sense, x must have N*N elements.

64*64

ans = 4096

Does it? That imresize call implies it will have 128*128 elements (or perhaps 128*128*3.)

128*128

ans = 16384

How do you fit 16,384 elements into a 4,096 element grid?

Answer 2

[Ryan]

Great, thanks for that!