how to crop an image equally

i want to divide this picture equally from the centre of the optic disc on a angle of 30 degree. but i dont no how to dvide it. I need a algorithm for this. i am sharing an demo image.. i have to crop thi im592 image in demo type image

i want crop this image in patches so that i can extraxct its feature

Answer 1

[KSSV]

I = imread('Im592.jpg') ;

[ny,nx,nz] = size(I) ;
[X,Y] = meshgrid(1:nx,1:ny) ;

C = round([nx/2 ny/2]) ;  % center 
R = abs(min(C)-min(nx,ny)) ;

% circle 
th = linspace(0,pi/2) ;
x = C(1)+R*cos(th) ; 
y = C(2)+R*sin(th) ;

figure
imshow(I)
hold on
plot(x,y,'r')

% Get inside part / crop
xp = [0 x 0] ; yp = [0 y 0] ;
idx = inpolygon(X(:),Y(:),xp,yp) ;
%
for i = 1:3
    T = I(:,:,i) ;
    T(~idx) = 255 ;
    I(:,:,i) = T ;
end

    
figure
imshow(I)

[Ruksana siddique]

sorry, this is not the correct answer

i have to dive the whole circle in 30 degree angle that is 180/6. like the image i attached to you

[Ruksana siddique]

but this program will crop the whole image and cut the image in arc

[KSSV]

crop means taking the required part from the image.......what you want? You want to draw a circle like shown?

sorry, this is not the correct answer you may not expect straight away answer sometimes......but given code shows you some hint with which you can proceed further.

[Ruksana siddique]

actually i want to crop a whole image in 6 parts.. each part crop from the centre of image at an angle of 30 degree

i already share the image how to cut the whole image sir

[Ruksana siddique]

can i again show the picture.. how to cut the whole image sir

[Ruksana siddique]

Sir there is an attachment so that you understand better..

Answer 2

[Ruksana siddique]

sir the program you send me. . in this the image is cut out at 30 degree

do you help me how will I crop the image from it's center