calculate_oritation_hist.m

function [hist,max_value]=calculate_oritation_hist(x,y,radius,gradient,angle,n,Sa)
sigma=radius/3;
radius_x_left=x-radius;
radius_x_right=x+radius;
radius_y_up=y-radius;
radius_y_down=y+radius;

sub_gradient=gradient(radius_y_up:radius_y_down,radius_x_left:radius_x_right);
sub_angle=angle(radius_y_up:radius_y_down,radius_x_left:radius_x_right);

X=-(x-radius_x_left):(radius_x_right-x);
Y=-(y-radius_y_up):(radius_y_down-y);
[XX,YY]=meshgrid(X,Y);

gaussian_weight=exp(-(XX.^2+YY.^2)/(2*sigma^2));
% gaussian_weight=1/(sqrt(2*pi)*sigma)*exp(-(XX.^2+YY.^2)/(2*sigma^2));
W1=sub_gradient.*gaussian_weight;%有高斯权重

W=double(Sa).*double(W1);   %c就是那个圆心坐标为（i，j）的圆形区域矩阵
% W=sub_gradient;%无高斯权重
% bin = 1 + round( n*(sub_angle + pi)/(2*pi));
% bin(bin == n +1)=1;

bin=round(sub_angle*n/360);
bin(bin>=n)=bin(bin>=n)-n;
bin(bin<0)=bin(bin<0)+n;
temp_hist=zeros(1,n);
for i=1:n
    wM = W(bin==i);
    if ~isempty(wM)
        temp_hist(i)=sum(wM(:));
    end
end

%%temp_hist(-1)=temp_hist(35)
%%temp_hist(0)=temp_hist(36)
hist=zeros(1,n);
hist(1)=(temp_hist(n-1)+temp_hist(3))/16+...
    4*(temp_hist(n)+temp_hist(2))/16+temp_hist(1)*6/16;
hist(2)=(temp_hist(n)+temp_hist(4))/16+...
    4*(temp_hist(1)+temp_hist(3))/16+temp_hist(2)*6/16;
% for j=3:1:n-2
%     hist(j)=(temp_hist(j-2)+temp_hist(j+2))/16+...
%     4*(temp_hist(j-1)+temp_hist(j+1))/16+temp_hist(j)*6/16;
% end

hist(3:n-2)=(temp_hist(1:n-4)+temp_hist(5:n))/16+...
4*(temp_hist(2:n-3)+temp_hist(4:n-1))/16+temp_hist(3:n-2)*6/16;
hist(n-1)=(temp_hist(n-3)+temp_hist(1))/16+...
    4*(temp_hist(n-2)+temp_hist(n))/16+temp_hist(n-1)*6/16;
hist(n)=(temp_hist(n-2)+temp_hist(2))/16+...
    4*(temp_hist(n-1)+temp_hist(1))/16+temp_hist(n)*6/16;

max_value=max(hist);
end