MATLAB: How to extract features of videos

extract featuresfeature extractionimage processingvideovideo processing

Hello.
I want to classify videos after extracting features.
When I use background substraction as extracting features, the result of classification is not good.
Could I get some ideas about feature extraction in videos?
This is code about background substraction. I want to use other methods for feature extraction
%// read the video:
list = dir('*.avi')
% loop through the filenames in the list
for k = 1:length(list)
    reader = VideoReader(list(k).name);
    vid = {};
    while hasFrame(reader)
        vid{end+1} = im2single(readFrame(reader));
    end
    %// simple background estimation using mean:
    bg = csvread('background.csv');
    bg = reshape(bg, 144, 180, 3);
    %// estimate foreground as deviation from estimated background:
    for i=1:25
        fIdx(i) = i; %// do it for frame 1 ~ 60
        fg{i} = sum( abs( vid{fIdx(i)} - bg ), 3 );
        fgh{i} = imresize(fg{i}, 0.2);
        
        fg{i} = reshape(fgh{i},[],1);
    end
    X = cell2mat(fg);

Best Answer

I extract some features in the attached demo. I compute a dynamic background from the last few frames and subtract it to get the changes, and I also plot the mean R, G, and G values. You could of course compute other things -- whatever you want. If background subtraction is not good for what you want to segment, then you'll have to devise a different segmentation routine. Background subtraction is not appropriate for all situations obviously.
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