Function and file name as an input argument

Hi everyone ,

Can anyone help me ? I am writing a function which is supposed to have a filename as an input argument. This fucntion is supposed to read all the raw files ( 2D gray images) from the file and stack the images . The output argument is the mean of the stacked image.

When i do it in a normal.m script it works but it does not when i try to do it in a function with the filename as an input argument.

Thx in advanve

function moy =Moyenne_Dark(filelocation)
Nrow = 2048;
NCol = 2040;

dir (filelocation);
matfiles = dir(fullfile(filelocation, '*.raw'));
nfiles = length(matfiles)
sum=uint16((zeros(2040,2048)));
for i = 1 : nfiles
    filename = matfiles(i).name ;
    image=fopen(filelocation, 'rb');
    M = uint16(fread(image, [NLigne, NColonne], 'uint16'));
    N = swapbytes(M)';
    sum=imadd(sum,N);
    fclose(image);
end
sum=imdivide(sum,nfiles);
moy= mean2(sum);
end

Answer 1

[Walter Roberson]

dir (filelocation);

That line is not contributing anything; you fetch the directory information and then throw it away.

matfiles = dir(fullfile(filelocation, '*.raw'));

misleading variable name for raw files ;-)

    filename = matfiles(i).name ;

No, that implies the files are in the current directory, but they are in the directory indicated by filelocation. Instead use

    filename = fullfile(filelocation, matfiles(i).name);
    

Also,

    sum=uint16((zeros(2040,2048)));

We recommend against naming any variable sum : chances are too high that you will want to also use sum() as a function in the same code. And it confuses readers.

    sum=imadd(sum,N);

There is a high risk that you are going to saturate uint16 when you add a bunch of uint16 together.

        N = swapbytes(M)';
        %...
        moy= mean2(sum);
        

mean2() does not care about the order the values are in, so there is no point in doing the transpose. Just accumulate into a [NLigne, NColonne] array without transposing.

[jad aoun]

thx a lot for your comment. However even with these changes i am still getting a "thre is not enough arguments" for my function. Do you have anyidea why ?

[Walter Roberson]

how are you invoking your function? show an example invocation?

[jad aoun]

I figured it out myself . Thank you a lot again.

[Faisal Sani Bala]

Hi, please can you share the working function which you got finally?