把几幅图像做合成运算之后 ，figure 平显示正常 p2显示为纯白图像这是为什么呢，看过p2的像素数值并不等于(255,255，255)，求高手解救。。。。下面是我的代码：

clc;

clear all;

% a=input('Enter the file name：','s'); % 输入图像

% b=input('Enter the file name：','s'); % 输入图像

% c=input('Enter the file name：','s'); % 输入图像

% d=input('Enter the file name：','s'); % 输入图像

BW1=imread(a);

BW2=imread(b);

BW3=imread(c);

BW4=imread(d);

[x,y,z]=size(BW1);

p=zeros(x,y,z);

p1=p;

p2=p;

p3=p;

p1=BW1+BW2+BW3+BW4;

figure,imshow(p1);

BW11=BW1(:,:,1);BW12=BW1(:,:,2);BW13=BW1(:,:,3);

BW21=BW2(:,:,1);BW22=BW2(:,:,2);BW23=BW2(:,:,3);

BW31=BW3(:,:,1);BW32=BW3(:,:,2);BW33=BW3(:,:,3);

BW41=BW4(:,:,1);BW42=BW4(:,:,2);BW43=BW4(:,:,3);

for i=1:x;

for j=1:y;

p2(i,j,1)=BW11(i,j)+BW21(i,j)-uint8((BW11(i,j)+BW21(i,j))/10);

p2(i,j,1)=p2(i,j,1)+BW31(i,j)-uint8((p2(i,j,1)+BW31(i,j))/10);

p2(i,j,1)=p2(i,j,1)+BW41(i,j)-uint8((p2(i,j,1)+BW41(i,j))/10);

p2(i,j,2)=BW12(i,j)+BW22(i,j)-uint8(2.5*((BW12(i,j)+BW22(i,j))/10));

p2(i,j,2)=p2(i,j,2)+BW32(i,j)-uint8(2.5*((p2(i,j,2)+BW32(i,j))/10));

p2(i,j,2)=p2(i,j,2)+BW42(i,j)-uint8(2.5*((p2(i,j,2)+BW42(i,j))/10));

p2(i,j,3)=BW13(i,j)+BW23(i,j)-uint8((BW13(i,j)+BW23(i,j))/10);

p2(i,j,3)=p2(i,j,3)+BW33(i,j)-uint8((p2(i,j,3)+BW33(i,j))/10);

p2(i,j,3)=p2(i,j,3)+BW43(i,j)-uint8((p2(i,j,3)+BW43(i,j))/10);

d=uint8(p2(i,j,1));

e=uint8(p2(i,j,2));

f=uint8(p2(i,j,3));

%         if p2(i,j,:)>255

%             p2(i,j,:)=255;

%         end

end

end

p4=zeros(10,10,3);

p4(:,:,1)=p2(1:10,1:10,1);

p4(:,:,2)=p2(1:10,1:10,2);

p4(:,:,3)=p2(1:10,1:10,3);

imwrite(p2,'d:\abc.bmp');

figure,imshow(p2);

figure,imshow(p4);