Finding the average background frame from a video sequence

Hi everyone

I have a video seqence and I want to apply the running average equation on this video sequence to estimate the background frame.let say I have a sequence of frames like

source=VideoReader('myvideo.avi'); frames=source.Numberofframes; for f=1:frames thisframe=read(source,f);

end

As I know that frames is equal to total number of frames in this video and f is changing after evry iteration now how can I find the average background frame which is

backgroundframe=(frame1+frame2+frame3+....+N)./frames;as in this case total number of frames are 1020. so it becomes

backgroundframe=(frame1+frame2+frame3+....+N)./1020.

how can i apply this equation.

Thanks

[Algorithms Analyst]

any help is appreciated...

Answer 1

[James]

Hi Algorithms Analyst, this is of interest to me because I'm trying to do something similar. I use a system command to run ffmpeg (www.ffmpeg.org/) to retrieve frames from the video, then average them by summing in a loop using 'imadd.m' and dividing the final sum.

 Frames = uint32(imread(strcat(Folder, File_basename, num2str(1), Frame_ext)) );
 for i = 1:(length(dir([Folder,File_basename)], '*',Frame_ext));
      Frames = imadd(Frames,uint32(imread(strcat(Folder,File_basename,num2str(i,'%04d'), Frame_ext))) );                     
  end
  AveFrames=uint8(imdivide(AveSAMPLEFrames,length(dir([Folder,File_basename)], '*',Frame_ext)) ));

Works pretty well for me when the object is moving and lighting stays relatively constant. Not the fastest method though. Would be interested to hear if you found any better solutions since this post.