写的matlab程序同态滤波最后的结果一片全黑怎么回事啊？？有没有人能帮我分析一下？

[Y12306]

写的matlab程序同态滤波最后的结果一片全黑怎么回事啊？？有没有人能帮我分析一下？
[image_0,map]=imread('E:/2.bmp');
image_0=rgb2gray(image_0);
image_0=double(image_0)/255;
image_1=log(image_0+1);
image_2=fft2(image_1);
n=3;
D0=0.05*pi;
rh=0.8;
rl=0.5;
[row,col]=size(image_2);
for k=1:1:row;
for l=1:1:col;
D1(k,l)=sqrt((k^2+1^2));
H(k,l)=rl+(rh/(1+(D0/D1(k,l))^(2*n)));
end
end

image_3=(image_2.*H);
image_4=ifft(image_3);
image_5=(exp(image_4)-1);

figure(1)
imshow(image_0,map)
figure(2)
imshow(real(image_5),map)

[lgstudyvc]

数据没出来