matlab摄像头

 1 clear all; 
 2 close all;
 3 clc;
 4 imaqmem(30000000); %申请缓存
 5 obj = videoinput(‘winvideo‘, 1, ‘YUY2_640x480‘);%创建ID为1的摄像头的视频对象，视频格式是 YUY2_640x480，这表示视频的分辨率为640x480。
 6 set(obj,‘ReturnedColorSpace‘,‘rgb‘);%返回rgb格式
 7 % set(obj,‘ReturnedColorSpace‘,‘grayscale‘);
 8 objRes=get(obj,‘VideoResolution‘);%获取分辨率[宽,高]
 9 nBands=get(obj,‘NumberOfBands‘);%获取通道数
10 
11 preview(obj);%实时显示
12 
13 start(obj);
14 h=figure(‘NumberTitle‘,‘off‘,‘Name‘,‘视频‘);         %新建窗口
15 set(h,‘doublebuffer‘,‘on‘,‘outerposition‘,get(0,‘screensize‘));
16 hold on;
17 axis off;
18 
19 box=uint8(zeros(objRes(2),objRes(1),nBands));
20 for i=objRes(2)/2-100:objRes(2)/2+100
21     for j=objRes(1)/2-100:objRes(1)/2+100
22         box(i,j,1)=255;
23     end
24 end
25 
26 while ishandle(h)
27     frame=getsnapshot(obj);
28     flushdata(obj);    
29     imshow(frame+box);
30     drawnow;
31 end
32 delete(obj);