Image Processing need to make an image circular

I was wondering if there is any way to crop an Image into a circular image I am using the mask function but i need it to be circular not just masked. This is my code I know i need some more work done but i need to figure this part first.

canvas=255*ones(3000,3000,3,'uint8');
A=imread('A.jpg');
F=imread('F.jpg');
C=imread('C.png');
E=imread('E.jpg');
A=A(:,200:1720,:);
C=C(9:1500,93:3093,:);
E=imresize(E,4);
I = E;
imageSize = size(I);
ci = [455, 450, 350]; % center and radius of circle ([c_row, c_col, r])
[xx,yy] = ndgrid((1:imageSize(1))-ci(1),(1:imageSize(2))-ci(2));
mask = uint8((xx.^2 + yy.^2)<ci(3)^2);
croppedImage = uint8(zeros(size(I)));
croppedImage(:,:,1) = I(:,:,1).*mask;
croppedImage(:,:,2) = I(:,:,2).*mask;
croppedImage(:,:,3) = I(:,:,3).*mask;
canvas(1:1080,1:1521,:)=A;
canvas(1510:3001,1:3001,:)=C;
canvas(1:720,1720:2999,:)=F;
canvas(900:1799,1050:1949,:)=croppedImage;
imshow(canvas)

[Leslie Dominguez]

Image preview

Answer 1

[Walter Roberson]

No. There are no data structures in MATLAB that are circular.

You have two choices:

1. Masking (alphadata)
2. Use a cell array with two columns, the second of which holds the pixels in this row of the image, and the first of which holds the offset to put the row at. There are no library routines to draw with such an image, but you could create one that used a separate graphics object for each row. With work you could probably create a single patch object with texture mapping (but it would sure be a lot easier to just use masking...)

[Leslie Dominguez]

What about creating a ring around this image? Like this but now I can't seem to get the image fixed.

canvas=255*ones(3000,3000,3,'uint8');
A=imread('A.jpg');
F=imread('F.jpg');
C=imread('C.png');
E=imread('E.jpg');
A=A(:,200:1720,:);
C=C(9:1500,93:3093,:);
F=imresize(F,[1500,1280]);
A=imresize(A, [1500,1521]);
Arch=imresize(E,4);
canvas(1:1500,1:1521,:)=A;
canvas(1510:3001,1:3001,:)=C;
canvas(1:1500,1720:2999,:)=F;
canvas(900:1799,1050:1949,:)=Arch;
r = 650;
rowx = 1370;
colx = 1500;
for n = -r:r
    d = round(sqrt(r^2 - n^2));
    canvas(rowx-d:rowx+d, colx+n, :) = canvas(rowx-d:rowx+d, 1500, :); 
end
imshow(canvas)

[Image Analyst]

Make sure you don't mix up (x,y) with (row,column). Matrices are NOT indexed as matrix(x, y) - they are indexed as matrix(y, x).

Attach images A, F, C, and E if you need more help.