MATLAB: DataStore for image sequence

Question

Hi everyone,

I am trying to set up a custom file datastore for image sequences. I am wondering now what data format the read() method has to output in that case so that the dynamic character of the data doesn't get lost. The docu only says m x n x 3(1) for (greyscale)-images but that cannot be used for sequential images. Is it then a cell array with 4D elements as it would be without using the datastore?

Thanks for your help!

Best,

Valentin

Answer 1

Hi, 

Considering you are referring to a video dataset when you say ‘image sequence’, you can write your ReadFcn in the following manner:

datapath='path_to_data'; 
fds = fileDatastore(datapath,'ReadFcn',@readVideo,'FileExtensions','.mp4');
data = readall(fds);
function vid = readVideo(file)
    vid=VideoReader(file);
end

You can refer to the below links for more information on the functions used above:

https://www.mathworks.com/help/matlab/ref/matlab.io.datastore.filedatastore.html

https://www.mathworks.com/help/matlab/ref/matlab.io.datastore.readall.html

https://www.mathworks.com/help/matlab/ref/videoreader.html