function output=blur(img,w)
img=double(img);
d=w*2+1
s=size(img)
output=[]
for r=1:d:s(1)
row=[];
for c=1:d:s(2)
if r+w<=s(1) && c+w<=s(2) && r-w>=1 && c-w>=1
tot=sum(sum(img((r-w):(r+w),(c-w):(c+w))));
val=tot/(d*d);
nxt=ones(d,d);
nxt(1:end,1:end)=val;
row=[row nxt];
elseif c+w<=s(2) && r-w>=1 && c-w>=1
tot=sum(sum(img((r-w):end,(c-w):(c+w))));
val=tot/(d*(s(1)-r+w));
nxt=ones((s(1)-r+w),d);
nxt(1:end,1:end)=val;
row=[row nxt];
elseif r+w<=s(1) && r-w>=1 && c-w>=1
tot=sum(sum(img((r-w):(r+w),(c-w):end)));
val=tot/(d*(s(2)-c+w));
nxt=ones(d,(s(2)-c+w));
nxt(1:end,1:end)=val;
row=[row nxt];
elseif r+w<=s(1) && c+w<=s(2) && r-w>=1
tot=sum(sum(img((r-w):(r+w),1:(c+w))));
val=tot/(d*(c+w));
nxt=ones(d,(c+w));
nxt(1:end,1:end)=val;
row=[row nxt];
elseif r+w<=s(1) && c+w<=s(2) && c-w>=1
tot=sum(sum(img(1:(r+w),(c-w):(c+w))));
val=tot/(d*(r+w));
nxt=ones((r+w),d);
nxt(1:end,1:end)=val;
row=[row nxt];
elseif r+w<=s(1) && c+w<=s(2)
tot=sum(sum(img(1:(r+w),1:(c+w))));
val=tot/((r+w)*(c+w));
nxt=ones((c+w),(r+w));
nxt(1:end,1:end)=val;
row=[row nxt];
elseif r-w>=1 && c-w>=1
tot=sum(sum(img((r-w):end,(c-w):end)));
val=tot/((s(1)-r+w)*(s(2)-c+w));
nxt=ones((s(1)-r+w),(s(2)-c+w));
nxt(1:end,1:end)=val;
row=[row nxt];
elseif r+w<=s(1) && c-w>=1
tot=sum(sum(img(1:(r+w),(c-w):end)));
val=tot/((r+w)*(s(2)-c+w));
nxt=ones((r+w),(s(2)-c+w));
nxt(1:end,1:end)=val;
row=[row nxt];
elseif c+w<=s(2) && r-w>=1
tot=sum(sum(img((r-w):end,1:(c+w))));
val=tot/((s(1)-r+w)*(c+w));
nxt=ones((s(1)-r+w),(c+w));
nxt(1:end,1:end)=val;
row=[row nxt];
end
end
output=[output;row];
end
row=[]
s2=size(output)
if s2(1)<s(1)
for c=1:d:s(2)
if c+w<=s(2) && c-w>=1
tot=sum(sum(img((s2(1)+1):s(1),(c-w):(c+w))));
val=tot/((s(1)-s2(1))*d);
nxt=ones((s(1)-s2(1)),d);
nxt(1:end,1:end)=val;
row=[row nxt];
elseif c+w<=s(2)
tot=sum(sum(img((s2(1)+1):s(1),1:(c+w))));
val=tot/((s(1)-s2(1))*(c+w));
nxt=ones((s(1)-s2(1)),(c+w));
nxt(1:end,1:end)=val;
row=[row nxt];
elseif c-w>=1
tot=sum(sum(img((s2(1)+1):s(1),(c-w):end)));
val=tot/((s(1)-s2(1))*(s2(2)-c+w));
nxt=ones((s(1)-s2(1)),(s2(2)-c+w));
nxt(1:end,1:end)=val;
row=[row nxt];
end
end
output=[output;row];
end
row=[]
col=[]
s3=size(output)
if s3(2)<s(2)
for r=1:d:s(1)
if r+w<=s(1) && r-w>=1
tot=sum(sum(img((r-w):(r+w),(s3(2)+1):s(2))));
val=tot/(d*(s(2)-s3(2)));
nxt=ones(d,(s(2)-s3(2)));
nxt(1:end,1:end)=val;
col=[col;nxt];
elseif r+w<=s(1)
tot=sum(sum(img(1:(r+w),(s3(2)+1):s(2))));
val=tot/((r+w)*(s(2)-s3(2)));
nxt=ones((r+w),(s(2)-s3(2)));
nxt(1:end,1:end)=val;
col=[col;nxt];
elseif r-w>=1
tot=sum(sum(img((r-w):(r+w),(s3(2)+1):s(2))));
val=tot/((s3(1)-r+w)*(s(2)-s3(2)));
nxt=ones((s3(1)-r+w),(s(2)-s3(2)));
nxt(1:end,1:end)=val;
col=[col;nxt];
end
end
s4=size(col)
if s4(1)<s3(1) || s4(1)<s(1)
tot=sum(sum(img((s2(1)+1):s(1),(s3(2)+1):s(2))));
val=tot/((s(1)-s2(1))*(s(2)-s3(2)));
nxt=ones((s(1)-s2(1)),(s(2)-s3(2)));
nxt(1:end,1:end)=val;
col=[col;nxt];
end
output=[output col];
end
output=uint8(output);