frierdscripwhbrightness.m

这是一个用带亮度傅立叶描述子提取纹理特征的程序

function ft=frierdscripwhbrightness(im)

ed=edge(im,'canny');
ethin=bwmorph(ed,'thin',Inf);
[m,n]=size(im);

ft=zeros(1,8);

%boundary pixels
[x,y]=find(ethin==1);
 
%centroid distance
N=length(x);
val=zeros(N,1);
% sita=zeros(N,1);

xc=sum(x)/N;
yc=sum(y)/N;

rd=sqrt((x-xc).^2+(y-yc).^2);
for i=1:N
    val(i)=im(x(i),y(i));
end
% b=[0 1];
% for i=1:N
%     a=[x(i)-xc y(i)-yc];
%     cossita=a*b'/sqrt(a(1)^2+a(2)^2);
%     if x(i)<xc
%         sita(i)=acos(cossita);
%     else
%         sita(i)=2*pi-acos(cossita);
%     end
% end
t=fft(rd.*val);
% t=fft(rd);
abst=abs(t);
%nt=abst/abst(1);

% u11=(x-xc)'*(y-yc);
% u20=(x-xc)'*(x-xc);
% u02=(y-yc)'*(y-yc);
% e=(u20+u02-sqrt((u20-u02)^2+4*u11^2))/(u20+u02+sqrt((u20-u02)^2+4*u11^2));
ft(1:8)=abst(1:8);
% ft(9)=e;