function [Outputprint,XofCenter,YofCenter] = centralizing(fingerprint,ctrl)
%	 modified by PRTsinghua@hotmail.com

imgN=size(fingerprint,1);
imgM=size(fingerprint,2);

image = wiener2(fingerprint,[3 3]);
[Gx,Gy] = gradient(image);
orientnum = wiener2(2.*Gx.*Gy,[3 3]);
orientden = wiener2((Gx.^2) - (Gy.^2),[3 3]);
W = 8;
ll = 9;
orient = zeros(imgN/W,imgM/W);
%-----------------------------------------------
points=(imgN/W)*(imgM/W);
for i = 1:1:points
    x = floor((i-1)/(imgM/W))*W+1;
    y = mod(i-1,(imgN/W))*W+1;
    numblock = orientnum(y:y+W-1,x:x+W-1);
    denblock = orientden(y:y+W-1,x:x+W-1);
    
    somma_num=sum(sum(numblock));
    somma_denom=sum(sum(denblock));
    
    if somma_denom ~= 0
        inside = somma_num/somma_denom;
        angle = 0.5*atan(inside);
    else
        angle = pi/2;
    end
    % each block
    if angle < 0
        if somma_num < 0
            angle = angle + pi/2;
        else
            angle = angle + pi;
        end
    else
        if somma_num > 0
            angle = angle + pi/2;
        end
    end
    orient(1+(y-1)/W,1+(x-1)/W) = angle;   
end

binarize = (orient < pi/2);
[bi,bj] = find(binarize);
xdir = zeros(W,W);
ydir = zeros(W,W);
for k = 1:1:size(bj,1)
    i = bj(k);
    j = bi(k);
    if orient(j,i) < pi/2
        x = fix(ll*cos(orient(j,i)-pi/2)/(W/2));
        y = fix(ll*sin(orient(j,i)-pi/2)/(W/2));
        xdir(j,i) = i-x;
        ydir(j,i) = j-y;
        
    end
end

binarize2 = zeros(imgN/W,imgM/W);
for i = 1:1:size(bj,1)
    x = bj(i);
    y = bi(i);
    if ~(xdir(y,x) < 1 | ydir(y,x) < 1 | xdir(y,x) > imgM/W | ydir(y,x) > imgN/W)
        while binarize(ydir(y,x),xdir(y,x)) > 0
            xtemp = xdir(y,x);
            ytemp = ydir(y,x);
            if xtemp < 1 | ytemp < 1 | xtemp > imgM/W | ytemp > imgN/W
                break;
            end
            x = xtemp;
            y = ytemp;
            if xdir(y,x) < 1 | ydir(y,x) < 1 | xdir(y,x) > imgM/W | ydir(y,x) > imgN/W
                if x-1 > 0
                    while binarize(y,x-1) > 0
                        x = x-1;
                        if x-1 < 1
                            break;
                        end
                    end
                end
                break;
            end
        end
    end
    binarize2(y,x) = binarize2(y,x)+1;
end

[temp,y] = max(binarize2(1:end-7,:));
[temp2,x] = max(temp);
angle = orient(y(x),x)-pi/2;
XofCenter=round(x*W-(W/2)-(ll/2)*cos(angle));
YofCenter=round(y(x)*W-(W/2)-(ll/2)*sin(angle));
Outputprint=binarize2;