getting error as " Undefined function 'exp' for input arguments of type 'uint8'." can someone help me resolve this

clc;
clear all;
close all;

I = imread('pluginfile_page-0001.jpg');
I = rgb2gray(I);
figure(1)
imshow(I);

I = imresize(I,[256 256]);

sigma = 1;
sig_s=1;
sig_r=1;
halfwid = sigma * 3;
halfwid = 1;
[xx, yy] = meshgrid(-halfwid:halfwid, -halfwid:halfwid);
Gg=1/16*[1 2 1;2 4 2; 1 2 1];
%Gg = exp(-(xx .^ 2 + yy .^ 2) / (2 * sigma ^ 2));

  [M,N]=size(I);
 
	modifyI=uint8((zeros(size(I)+2)));
    
 
	%COPY THE ORIGINAL IMAGE MATRIX TO THE PADDED MATRIX
	        for x=1:size(I,1)
	            for y=1:size(I,2)
	                modifyI(x+1,y+1)=I(x,y);
	            end
            end
             
	        figure(2);
	        imshow(modifyI);
	        %LET THE WINDOW BE AN ARRAY
	      %STORE THE 3-by-3 NEIGHBOUR VALUES IN THE ARRAY
	      %SORT AND FIND THE MIDDLE ELEMENT
          Gf_num1=0;
          Gf_den1=0;
          Igy=uint8(conv2(modifyI,Gg,'same'));
          figure(4);
          imshow(Igy);
          
	for i= 2:size(modifyI,1)-1
	    for j=2:size(modifyI,2)-1
            
	        for x=-1:1
	            for y=-1:1
                    
                     %window(inc)=modifyI(i+x-1,j+y-1)
                    Gr =  exp(-(abs(Igy(i+x,j+y)-modifyI(i,j)))^2/2*sig_r^2);
                     
	                %Gr = exp(-((abs((Igy(i+x,j+y)-modifyI(i,j)))^2)/2*sig_r^2));
              
                      Gs=exp(-(((i+x)-i)^2+((j+y)-j)^2)/2*sig_s^2);
                    
                
                    Gf_num = Gs*Gr*Igy(i+x,j+y);
                    Gf_num1=Gf_num1+Gf_num;
                    
                    Gf_den=Gs*Gr;
                    Gf_den1 = Gf_den+Gf_den1;
                    
                end
            end
            Gfg(i-1,j-1) = Gf_num1 / Gf_den1;
            
     
        end
            
    end
    
    %Gfg1 =im2uint8(Gfg);
   % Gfg=uint8(Gfg);
   figure(3);
    imshow(Gfg);

Answer 1

[Image Analyst]

If it doesn't like uint8, then cast it to double

I = double(rgb2gray(I));