examples to convert image to polar coordinates do it explicitly - want a slick matrix method

Question

I am trying to convert an image from cartesian to polar coordinates.

I know how to do it explicitly using for loops, but I am looking for something more compact.

Answer 1

I notice that the answer from bla is from polar to cartesian coordinates. However the question is in the opposite direction.

I=imread('output.png');   %read image
I1=flipud(I);
A=imresize(I1,[1024 1024]);
A1=double(A(:,:,1));
A2=double(A(:,:,2));
A3=double(A(:,:,3));  %rgb3 channel to double
[m n]=size(A1);
[t r]=meshgrid(linspace(-pi,pi,n),1:m); %Original coordinate

M=2*m;
N=2*n;
[NN MM]=meshgrid((1:N)-n-0.5,(1:M)-m-0.5);
T=atan2(NN,MM);
R=sqrt(MM.^2+NN.^2);                  

B1=interp2(t,r,A1,T,R,'linear',0);
B2=interp2(t,r,A2,T,R,'linear',0);
B3=interp2(t,r,A3,T,R,'linear',0); %rgb3 channel Interpolation
B=uint8(cat(3,B1,B2,B3));        

subplot(211),imshow(I);  %draw the Original Picture
subplot(212),imshow(B);  %draw the result