(??? Undefined function or variable 'imshow

Hello everyone, I need some help. I am trying to change the colour of an image but got this error(??? Undefined function or variable 'imshow'.) below is the code; Meanwhile I don't the Image Processing Tool Box License. Is there any other way.

A=imread('C:\Users\sanni.2020\Desktop\cow.jpg','jpg'); 
A=image(); 
A= repmat(double(A)./255,[1 1 3]); 
s=input('input color:'); 
if (strcmp(s,'red')==1) 
A(:,:,2)=0; 
A(:,:,3)=0; 
elseif (strcmp(s,'green')==1) 
A(:,:,1)=0; 
A(:,:,3)=0; 
elseif (strcmp(s,'blue')==1) 
A(:,:,1)=0; 
A(:,:,2)=0; 
end 
imshow();
hold off
end

input color:'red';

??? Undefined function or variable 'imshow'.

[KSSV]

You can try using image or pcolor.

[Walter Roberson]

Which MATLAB version are you using? In old enough matlab, imshow was part of the Image Processing Toolbox

[Philips Sanni]

Matlab version 7.9.0 (R2009b) version. There is no image processing toolbox

[Philips Sanni]

@KSSV Just tried it. Another error pops out

??? Error using ==> surface

CData must be an M-by-N matrix or M-by-N-by-3 array

Error in ==> pcolor at 71

hh = surface(zeros(size(x)),x,'parent',cax);

Answer 1

[Walter Roberson]

In R2009b, imshow() was part of the Image Processing Toolbox. As you do not have that toolbox, you will not be able to use imshow()

I recommend that you use

image(A)

[Philips Sanni]

I tried image(A)

This error came up ??? Subscript indices must either be real positive integers or logicals.

[Walter Roberson]

Somewhere in your code, you assign a value to a variable named image -- or perhaps you did that at some point in the past and have not cleared your variables since then.

Also, you currently have

A=imread('C:\Users\sanni.2020\Desktop\cow.jpg','jpg'); 
A=image(); 

s legal, but it will completely replace the the cow image you read in, replacing it with a graphics object handle to the default image.

[Walter Roberson]

A = imread('cameraman.tif');
A = image();

A

A = 
  Image with properties:

           CData: [64×64 double]
    CDataMapping: 'direct'

  Show all properties

Notice that A = image() was a call to the image() function and asked for a default image to be displayed and for the object handle to be assigned to A.