MATLAB: Average every n elements in matrix

averageImage Processing Toolboxvideo processing

I have a 67560×75 matrix that consists of 40×75 matrices tiled on top of each other for 1689 frames of video.

I want to get a 40×75 matrix where each element is the average of the corresponding (i,j) position over all 1689 frames. Thanks

Best Answer

squeeze( mean(reshape(M, 40, [], 75),2) )

Related Solutions

MATLAB: Extracting frames using mmreader and calculate and substract mean from data

xyloObj = mmreader('xylophone.mpg');
%Make a 4d rgb volume
V = zeros(xyloObj.Height,xyloObj.width,3,xyloObj.NumberOfFrames,'uint8');
for ii = 1:size(V,4)
    V(:,:,:,ii) = read(xyloObj,ii);
end    
%subtract mean (V zero mean)
V = double(V); %must be double (or single)
Vzmean = bsxfun(@minus,V,mean(mean(V,1),2));

MATLAB: Can’t take the mean of a 2D matrix (Array indices must be positive integers or logical values.)

You are using mean both as a function name and a variable name.

Also, if you read the doc for mean, you will notice you can explicitly set the dimension to be reduced. If I recall correctly the same is true for std.

Best Answer

Related Solutions

MATLAB: Extracting frames using mmreader and calculate and substract mean from data

MATLAB: Can’t take the mean of a 2D matrix (Array indices must be positive integers or logical values.)

Related Question