How do I access images from directories using an input command for the extensive file?

I have a function which accesses images from a directory using inputs dirname and the filetype. When I type filenames = image(dirname,filetype), (e.g. filenames = image('/Users/Macbookair','jpg'), I can access all the files from the directory if the code has the line fileIdentity = fullfile(dirname, '*.jpg').

However, if I type in filenames = image('/Users/Macbookair','png'), the folders of jpg still appear in the command window. My question is how do I add an input command, such as filetype, so that whenever I type 'png', 'jpg' or any other extensive file it will show up as that specific file.

Thank you!

[Walter Roberson]

Why did you name your function "image", when that is the name of a key matlab function for drawing images? imshow() and imagesc() also internally depend upon image() so by naming your function "image" you make it quite difficult to draw images.

[Walter Roberson]

We do not know how your existing function accesses file names, which makes it difficult to know what to suggest.

Answer 1

[Neuropragmatist]

In the example function you gave the second input 'fileType' is not used, is that the problem?

You could use this in the line calling fullfile to get only the filetypes you want, i.e.:

function [filenames] = GenerateImageList(dirname, fileType)
    fileIdentity = fullfile(dirname, ['*' fileType]);
    files = dir(fileIdentity);

    for i = 1:length(files) 
        filenames = files(i).name;
        fprintf('%s\n', filenames);
    end
end

For example you can run this code as:

filenames = GenerateImageList(pwd,'png')
% or
filenames = GenerateImageList(pwd,'jpg')

However, there are some problems with your code - if there are no files with the extension you ask for the function throws an error because filenames is left undefined. Also, I think you want filenames to contain a list of all the filenames? But the way it is written here it will only ever contain the last filename it found because you overwite it on every loop. Might I suggest something like this:

function [filenames] = GenerateImageList(dirname, fileType)
    fileIdentity = fullfile(dirname, ['*' fileType]);
    files = dir(fileIdentity);
    filenames = {files(:).name};
    fprintf(1, '%s\n', filenames{:})
end

If you don't need to display the text in the command window for every filename (why do you want that?) you can just call dir directly for the filename list:

function [filenames] = GenerateImageList(dirname, fileType)
    df = dir(fullfile(dirname, ['*' fileType]));
    filenames = {df(:).name};
end

And then maybe you don't need the GenerateImageList function at all, you could just put those lines of code directly inb the parent function...

Hope this helps,

M.

[Sara Foster]

Thanks for the answer! I'll fix it up now. Sorry to bother but I was wondering if you could delete the code because I'm afraid someone will use my original code and it could count for plagarism.

[Neuropragmatist]

I think that would go against the idea of this forum... besides which this code is so simple that I don't think plagiarism is an issue.

M.

[Sara Foster]

That's alright, I guess I'll change my code... thanks for help.

[Walter Roberson]

If someone uses your original code they will not be able to create a functional version of the assignment.

Metioche's code is pretty basic in MATLAB.

[Walter Roberson]

I recommend using fullfile(dirname,.....) on the {} so that fully qualified file names are returned.

[Neuropragmatist]

Yea, that's a good idea.

M.

[Sara Foster]

Thanks for the help!