直接用matlab读取camera，并实时处理，将处理结果制成demo

%获取摄像头视频，并计算倾斜角，OK。
aviobj.quality = 100;
vid = videoinput('winvideo',1);
set(vid,'returnedcolorspace','rgb');
set(vid,'framespertrigger',10);
set(vid,'timerperiod',1);
set(vid,'triggerrepeat',0);
set(vid,'timeout',10);
vidRes = get(vid, 'VideoResolution');
nBands = get(vid, 'NumberOfBands');
subplot(1,2,1);
hImage = imshow( zeros(vidRes(2), vidRes(1), nBands),'truesize' );
preview(vid,hImage);
%frame{1} = getsnapshot(vid);
j=0;
while(1)
tic;
j=j+1;
   str = get(gcf,'currentkey');
   if strcmp(str,'space')
      break;
   else
    frame = getsnapshot(vid);%frame是当前的一帧彩色图像
    %gray=rgb2gray(frame);
    %subplot(1,2,2);plot(BMetric(event.Data,1),'-.r');
    angle=Aangle(frame);
    %subplot(1,2,2),imshow(gray,'truesize');
   % subplot(1,2,2),axis( [0 2000 0 100]),plot(j,angle,'-or'),hold on;
  
   end
 m(:,j)=getframe(gcf);
toc;
end
MOVIE2AVI(m,'angle1.avi','FPS',3); %convert the movie matrix an avi file