About the frame

Question

Pan 2012-4-29

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/36889-about-the-frame

Hellow, everybody

I want to ask that a lot of frames can be became a short video. because I extract some ketframs from the video, then I must consist of video from the keyframes.

this is my current code

clear all;
load glasses      % glasses.avi
[m,n,c,f]=size(xa);   % [480 640 3 203]
h=zeros(1,256);   % 0~255pixal
e=zeros(1,326);    
a=zeros(1,326);
dif=zeros(1,326);
se=zeros(1,326);
b=zeros(1,326);
c=3; 
for ix=3:326
          h=zeros(1,256);    
              for ii=1:m
                  for jj=1:n                
                     h(xa(ii,jj,c,ix)+1)= h(xa(ii,jj,c,ix)+1)+1;   
                   end
              end
             % figure(1)
             % plot(h)
              pf=h/(m*n);
             % figure(2)
             % plot(pf)
              for ii=1:256
                  if(pf(ii)==0)   % pf為0，則q(消息量)為0
                      q(ii)=0;
                else
                      q(ii)=-1.*log2(pf(ii));    %pf不為0，則用log去計算出q(消息量)
                  end
              end
              ef=pf.*q;   
              e(ix)=sum(pf.*q);     
          em=sort(ef,2,'descend');
          s=0;
          for k=1:256
             s=s+em(k);
             %if (s>=0.7*e(ix) ) 
             if (s>=0.07*e(ix) )
                se(ix)=s; 
               break;   
              end
          end
       a(ix)=k;
       s=0;
       for k=a(ix):256
             s=s+em(k);
       end
       b(ix)=s;  
  end
  i=1;
  num=0;
   for ix=3:326
       if(ix<326)
         dif(ix)=abs(b(ix)-b(ix+1));
         if(dif(ix)>0.21)
         ix
         num=num+1;
         figure(i)
         i=i+1;
         imshow(uint8(xa(:,:,:,ix)))
        end
       end
   end

could you give me some advices,thanks!!

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Walter Roberson 2012-4-29

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/36889-about-the-frame#answer_46109

See VideoWriter() or the earlier avifile(); or movie2avi()

3 个评论
显示 1更早的评论隐藏 1更早的评论

Walter Roberson 2012-4-29

Use the VideoWriter class to open an AVI file for writing. Then in the loop, at each point that you have a frame ready to add to the video, use the appropriate VideoWriter class call to add the frame to the video. When you have finished processing all of the frames, close the VideoWriter object.

You can refer to the VideoWriter documentation for an example.

Pan 2012-4-29