How to fill the gaps on the boundary surface of the cone using MATLAB?

Hi Mathworks community members

I am utilizing the Dr. Bruno Luong's code to fill the gaps. i am using P=[1 2 3; 8 0 4; 7 6 5] to fill the gaps on the boundary surface but some gaps cannot be filled successfuly. using this code, the gaps were filled as 3s. So, i need to adjust the P because its not filling all the gaps. Please anyone can guide me how to overcome this problem.

Aorg = load()
Aorg = s.Aorg;
gapmax = 10; 
[m,n] = size(Aorg);
A = double(Aorg>0); 
P=[1 2 3;
   8 0 4;
   7 6 5];
Apad = zeros(m+2,n+2);
maxattempt = 10;
for niter = 1:maxattempt  
    Apad(2:end-1,2:end-1) = A>0;
    B = zeros(m,n,8);
    for k=1:8
        [i,j] = find(P==k);
        B(:,:,k) = Apad(i-2+(2:end-1),j-2+(2:end-1));
    end
    As = A>0 & sum(diff(B(:,:,[1:8 1]),1,3)==1,3)<=1;
    [y,x] = find(As);
    if isempty(x)
        break
    end
    p = length(x);
    xy = [x,y];
    xy1 = reshape(xy,1,[],2);
    xy2 = reshape(xy,[],1,2);
    d = sum(abs(xy1-xy2),3);
    d(d==0) = NaN;
    i = (1:size(d,1))';
    [dmin,j] = min(d,[],2);
    keep = dmin <= gapmax;
    i = i(keep);
    j = j(keep);
    for k=1:length(i)
        xyi = xy(i(k),:);
        xyj = xy(j(k),:);
        dxy = xyi-xyj;
        if abs(dxy(1)) > abs(dxy(2))
            xr = linspace(xyi(1),xyj(1),abs(dxy(1))+1);
            yr = round(interp1([xyi(1),xyj(1)],[xyi(2),xyj(2)],xr));
        else
            yr = linspace(xyi(2),xyj(2),abs(dxy(2))+1);
            xr = round(interp1([xyi(2),xyj(2)],[xyi(1),xyj(1)],yr));
        end
        A(sub2ind(size(A),yr(2:end-1),xr(2:end-1))) = 3; 
    end
end

Answer 1

[Image Analyst]

The code didn't run so I repaired and improved it below. Other than that I don't know anything about it because unfortunately there are no comments in it to explain it. Good programming practice requires comments.

However I thought that in your other post you said that my bwconvexhull() method was working fine. If it's not anymore, then let me know why not.

Aorg = load('Matrix_Boundary_fills_1s_only.txt')
subplot(2, 1, 1);
imshow(Aorg, []);
title('Input : Aorg', 'FontSize', 20);

gapmax = 10;
[m,n] = size(Aorg);
A = double(Aorg>0);
P=[1 2 3;
	8 0 4;
	7 6 5];
Apad = zeros(m+2,n+2);
maxattempt = 10;
for niter = 1:maxattempt
	Apad(2:end-1,2:end-1) = A>0;
	B = zeros(m,n,8);
	for k=1:8
		[i,j] = find(P==k);
		B(:,:,k) = Apad(i-2+(2:end-1),j-2+(2:end-1));
	end
	As = A>0 & sum(diff(B(:,:,[1:8 1]),1,3)==1,3)<=1;
	[y,x] = find(As);
	if isempty(x)
		break
	end
	p = length(x);
	xy = [x,y];
	xy1 = reshape(xy,1,[],2);
	xy2 = reshape(xy,[],1,2);
	d = sum(abs(xy1-xy2),3);
	d(d==0) = NaN;
	i = (1:size(d,1))';
	[dmin,j] = min(d,[],2);
	keep = dmin <= gapmax;
	i = i(keep);
	j = j(keep);
	for k=1:length(i)
		xyi = xy(i(k),:);
		xyj = xy(j(k),:);
		dxy = xyi-xyj;
		if abs(dxy(1)) > abs(dxy(2))
			xr = linspace(xyi(1),xyj(1),abs(dxy(1))+1);
			yr = round(interp1([xyi(1),xyj(1)],[xyi(2),xyj(2)],xr));
		else
			yr = linspace(xyi(2),xyj(2),abs(dxy(2))+1);
			xr = round(interp1([xyi(2),xyj(2)],[xyi(1),xyj(1)],yr));
		end
		A(sub2ind(size(A),yr(2:end-1),xr(2:end-1))) = 3;
	end
end
subplot(2, 1, 2);
imshow(A, []);
title('Output : A', 'FontSize', 20);

[M.S. Khan]

Thanks Image Analyst for your reply. The screen shot heighlight the gaps in the matrix A. i have heighlighted them with blue color on the left boundary. i need to fill these gaps. Please guide me. Regards.

[Image Analyst]

Why can't you just use beconvhull?

chImage = bwconvhull(binaryImage);
perimeterImage = bwperim(chImage);

[M.S. Khan]

Thanks image analyst. Yes, i am using: perimeterImage = bwperim(chImage);

but in the image, i am getting gaps as shown in the image with blue color. which is making problem for me. First, i want to fill all the gaps on the boundary surface and then will apply bwperim() to acheive complete outer shell without any gaps on it.

Also, i think,

chImage = bwconvhull(binaryImage)

can only be used for convex images which cannot cover the concave images.

My objective is covering the gaps on the boundary surface.

i have used the above code to fill the gaps and label with 3 but still i could not succeed to fill all the gaps. Any guidance please.

Regards