matlab人脸检测程序的问题，小白，求大神解答

[beifulaoji123190]

bbox = step(faceDetector,aa); %aa是输入的图像
[m, n] = size(bbox);
flags = ones(1,m); %m不是就等于1吗？
count1 = 0;
count2 = 0;
for i = 1:m
count1 = 0;
count2 = 0;
for d = bbox(i,1):bbox(i,1)+bbox(i,3) %这是什么意思？bbox(i:)代表的是什么，查不到啊
for e = bbox(i,2):bbox(i,2)+bbox(i,4)
if BW(e,d) == 255
count2 = count2+1;
end
count1 = count1+1;
end
end
if count2/count1<0.3 %这是？
flags(i) = 0;
end
end
for i = 1:m
if bbox(i,3)*bbox(i,4)<100 %这是？
flags(i)=0;
end
end
figure
imshow(bb)
title('人脸检测出的图像');
for i=1:m %做啥？
hold on
if flags(i) == 1
rectangle('Position',bbox(i,:),'LineWidth',2,'EdgeColor',[1 1 0]);
end
end