Error using imfinfo when using nested loop, but not when using single loop to process same files

The imfinfo function is working perfectly when I process files in single folder. For example using the code given here where the matlab file is in the same folder as the files being processed:

baseFileNames=dir('*.tif');
fileinfo1=imfinfo(sprintf('%s',baseFileNames(1).name));
W=fileinfo1.Width;
H=fileinfo1.Height;
n=length(baseFileNames); 
F=n.*5;

However, when I try to apply the same code on multiple subfolders, I get an error at the fileinfo1 step that it can't read the first file in the folder:

""Error using imfinfo (line 142)

Unable to open file "B12N1_EBC_CaRec_session4_FullFramImaging_001.tif" for reading."

The code I use is as following:

start_path = fullfile(cd);
% Ask user to confirm or change.
topLevelFolder = uigetdir(start_path);
if topLevelFolder == 0
	return;
end

% Get list of all subfolders.
allSubFolders = genpath(topLevelFolder);
% Parse into a cell array.
remain = allSubFolders;
listOfFolderNames = {};

while true
	[singleSubFolder, remain] = strtok(remain, ';');
	if isempty(singleSubFolder)
		break;
	end
	listOfFolderNames = [listOfFolderNames singleSubFolder];
end
numberOfFolders = length(listOfFolderNames)

%.............Process all image files in those folders...................
for k = 1 : numberOfFolders;
    
	% Get this folder and print it out.
	thisFolder = listOfFolderNames{k};
	fprintf('Processing folder %s\n', thisFolder); 

if strfind(thisFolder, 'Frame')
    
baseFileNames = dir(sprintf('%s/*.tif', thisFolder));	
fileinfo1=imfinfo(sprintf('%s',baseFileNames(1).name));
W=fileinfo1.Width;
H=fileinfo1.Height;
n=length(baseFileNames); 
F=n.*5;
%Rest of code
end
end

baseFileNames give exactly the same output in both conditions, however, the fileinfo1 is only giving output in the first case. Please help!!!

[Stephen23]

Using fullfile with one input does nothing. Better:

start_path = pwd;

Answer 1

[Walter Roberson]

start_path = fullfile(cd);
% Ask user to confirm or change.
topLevelFolder = uigetdir(start_path);
if topLevelFolder == 0
	return;
end

dinfo = dir( fullfile(topLevelFolder, '**', '*Frame*') );   %all *Frame* folders
dinfo(~[dinfo.isdir]) = [];  %remove non-folders
dinfo(ismember({dinfo.name}, {'.', '..'})) = [];  %remove . and ..
listOfFolderNames = fullfile({dinfo.folder}, {dinfo.name});
numberOfFolders = length(listOfFolderNames);

for k = 1 : numberOfFolders;
    
	% Get this folder and print it out.
	thisFolder = listOfFolderNames{k};
	fprintf('Processing folder %s\n', thisFolder); 
 
        tinfo = dir(fullfile(thisFolder, '*.tif'));
        listOfFileNames = fullfile({tinfo.folder}, {tinfo.name});
        numberOfFiles = length(listOfFileNames);
        for N = 1 : numberOfFiles
            thisfile = listOfFileNames{N};
            fileinfo1 = imfinfo(thisfile);
            W = fileinfo1.Width;
            H = fileinfo1.Height;
            n = numberOfFiles;     %hard to see why you would want this
            F = n.*5;
            %other code 
        end
end

[Lina Koronfel]

Thanks alot!! I did some modifications using your recommendations and now it is working perfect. However, I'm curious as whether these two commands are different? Since my understanding is that they give similar output:

dir(fullfile(thisFolder, '*.tif')); % Your recommendation

dir(sprintf('%s/*.tif', thisFolder)); % What I used earlier

[Walter Roberson]

fullfile works regardless of operating system.