What is the problem with my code? please help me

function main()
    clc
    clear close all
    
    
    global bimg m n k block varr;
    m=1; n=0; k=1; block=0;
    
    bimg=imread('p.tif');
    varr=zeros(1,1024);
    
    img=imread('pep.tif');
    lab=rgb2lab(img);
    
    l=lab(:,:,1);
    a=lab(:,:,2);
    b=lab(:,:,3);
    
    
    
    img_block=blockproc(b,[16,16], @embedding, 'BorderSize', [1,1], 'Trimborder', true);
    
    
    w_lab=cat(l,a,img_block);
    w_img=lab2rgb(w_lab);
    
    subplot(1,2,1); imshow(img); title('Original Image');
    subplot(1,2,2); imshow(w_img); title('Watermarked Image');
    
    
    imwrite(im2unit8(w_img), 'wimage.png');
    save('emb.mat', 'varr');
    
    psnr_val=psnr(img, im2unit8(w_img));
    
end










function [inv_randon]=embedding(block_struct)
    data=block_struct.data;
    theta=0:179;
    
    
    randon_trans=randon(data, theta);
    portion=randon_trans(5:6, 5:6);
    [V,J]=jordan(portion);
    
    
    global bimg m n k block varr;
    block=block+1;
    q=3;
    det=25;
    vmax=max(V(:));
    
    
    bmodq=mod(block,q);
    Q=(bmodq/(vmax*del))+(vamx*del);
    
    
    
    q=1;
    p=1;
    
    for i=1:4
        n=n+1;
        
        if n==33
            m=m+1;
            n=1;
        end
        if q==3
        q=1;
        p=2;
        end
        
        if bimg(m,n)==1
            V(p,q)=V(p,q)+Q;
            
        else
            V(p,q)=V(p,q)+bmodq;
        end
        
        
        varr(1,k)=V(p,q);
        k=k+1;
        q=q+1;
    end
    
    
    inv_jor=real(V*J/V);
    randon_trans(5:6, 5:6)=inv_jor;
    
    output_size=max(size(data));
    inv_randon=irandon(randon_trans, theta, output_size);
end
        

[Rik]

Apart from the use of clc, clear, close all, and the use of global variables I don't immediately see the source of the problem. What line gives an error and what is the full error text?

[SUBROTO KUNDU]

Function BLOCKPROC encountered an error

while evaluating the user supplied

function handle, FUN.

The cause of the error was:

Undefined function 'randon' for input
arguments of type 'double'.

Error in testing>embedding (line 52)
    randon_trans=randon(data, theta);

Error in blockprocFunDispatcher (line
13)
        output_block =
        fun(block_struct);

Error in blockprocInMemory (line 80)
[ul_output fun_nargout] =
blockprocFunDispatcher(fun,block_struct,...

Error in blockproc (line 236)
    result_image =
    blockprocInMemory(source,fun,options);
    
Error in testing (line 21)
    img_block=blockproc(b,[16,16],
    @embedding, 'BorderSize', [1,1],
    'Trimborder', true);

Answer 1

[Guillaume]

Isn't the error message clear enough?

Undefined function 'randon' ...

Indeed, I'm not aware of a randon function in matlab. Maybe you've written you own function, in which case it must be on the path, but most likely you meant to call the radon (with only one n) function.