How to use different file format in MATLAB

Hi there,

I was using same file format (.tif) as input while processing with my following code. However, I have got new images with other formats like jpg, bmp.

I was previously using the below line and every time I need to change the extension manually in

    M = dir(fullfile(imgPath,'*.tif'));

to work with different extension.

In most cases in one folder of the file extensions are different it only works with .tif and ignore others.

Any advice will be highly appreciated.

Answer 1

[Guillaume]

Just get all the files in the directory and keep only the ones with the extensions you want. You could even get the list of all valid image extension from imformats:

%option 1:
extensions = {'bmp', 'tif', jpg'}; %define allowed extensions yourself
%option 2:
registry = imformats; %get all image type supported by matlab
extensions = [registry.ext]; %and get their extensions

allfiles = dir(fullfile(somepath, '*.*')); 
isimage = arrayfun(@(f) ~f.isdir && any(strcmp(regexp(f.name, '\.(.*)$', 'tokens', 'once'), extensions')), allfiles);
imagefiles = allfiles(isimage);
for imagefile = imagefiles'
    Im = imread(fullfile(somepath, imagefile.name));
    ...
end

[Siam]

Now I can process using the second option for my images and it is working.

Thank you very much.

Answer 2

[Image Analyst]

Try this snippet:

ImageFiles = dir([handles.imageFolder '\*.*']);
for Index = 1:length(ImageFiles)
  baseFileName = ImageFiles(Index).name;
  [folder, name, ext] = fileparts(baseFileName);
  ext = upper(ext);
  if strcmpi(name, 'contours')
    continue;
  end
  % Allow only tif, JPG, PNG, or BMP
  if strcmpi(ext, '.TIF') == 1 || strcmpi(ext, '.JPG') == 1 || strcmpi(ext, '.TIF') == 1    if strcmp(ext, '.PNG') == 1
  %            if strcmp(baseFileName, '.') == 0 && strcmp(baseFileName, '..') == 0 && strcmp(baseFileName, 'Thumbs.db') == 0
    ListOfImageNames = [ListOfImageNames baseFileName];
  end
end

[Siam]

Thank you for your advice however; I am calling imgPath in a function and therefore I need to use imgPath somehow as I was using the below line but it works only for .tif images

M = dir(fullfile(imgPath,'*.tif'));

You have advised me to use

ImageFiles = dir([handles.imageFolder '\*.*']);

I am not sure how I can use imgPath in this case.

Thank you once again.

[Image Analyst]

handles.imageFolder is what you called imgPath. Look up fullfile in the help.

Guillaume and I both gave basically the same answer: get them all and keep the ones you want. You accepted his answer so I assume everything is working now. Alternatively you can just all dir a bunch of times and append them all.

% Determine where demo folder is (works with all versions).
folder = fileparts(which('cameraman.tif')); 
tiffFiles = dir(fullfile(folder, '*.tif'))
pngFiles = dir(fullfile(folder, '*.png'))
jpgFiles = dir(fullfile(folder, '*.jpg'))
bmpFiles = dir(fullfile(folder, '*.bmp'))
allImageFiles = [tiffFiles; pngFiles; jpgFiles; bmpFiles]

Obviously if you already have a folder in variable imgPath, then you can just use imgPath everywhere I used folder, and skip the first line of the code above.

[Siam]

Dear Image Analyst,

At the beginning I was a little bit confused where to use the imgPath. However, I have changed the folder to imgPath with your one and it is working fine too. Thank you very much.

[Image Analyst]

You're welcome. As you figured out folder is just your directory, which you called imgPath, so it's

tiffFiles = dir(fullfile(imgPath, '*.tif'))
pngFiles = dir(fullfile(imgPath, '*.png'))
jpgFiles = dir(fullfile(imgPath, '*.jpg'))
bmpFiles = dir(fullfile(imgPath, '*.bmp'))
allImageFiles = [tiffFiles; pngFiles; jpgFiles; bmpFiles]

If you like the code, you can "Vote" for my answer.

[Siam]

Sorry for the delay Image Analyst. This one also works. Great help. Ty.