How to read and work with all the files from a directory ?

I have a directory full of image-files. I want to read all the files and then calculate the number of white pixel present for each of the files then write to to another file. To achieve this I used following code but in vein.

mydir = 'E:\matlab\dog\';

allentries = dir(mydir); 

diridxs = [allentries.isdir];

alldirs = allentries(diridxs); 

allfiles = allentries(~diridxs);

for ctr = 1:length(allfiles)

      disp(nnz(edge(rgb2gray(imread(allfiles(ctr).name)))));

end

After using this code matlab is showing some error [File "247000.jpg" does not exist]. Though that file exists in that path. How to get rid of that problem?

Answer 1

[Walter Roberson]

fullfile(mydir, allfiles(ctr).name)

[Sayak]

I have used that code and it works perfectly but the problem is that each time I use the number of white pixel count (using nnz() function) it only shows it sequentially. I have used the escape sequence to make new line ('\n') but in the output file does not seem to process the '\n'. How to deal with that?

My code so far::

mydir = 'E:\matlab\dog\';

fid=fopen('E:\matlab\all data.txt','w');

allentries = dir(mydir); % array of all files and dirs within target

diridxs = [allentries.isdir];

alldirs = allentries(diridxs); % array of all the dirs

allfiles = allentries(~diridxs); % array of all the files

for ctr = 1:length(allfiles)

      x = fullfile(mydir, allfiles(ctr).name);

      %disp(x);

      pix = nnz(edge(rgb2gray(imread(x)))); 

      fprintf(fid,'%d\n',pix); // *""\n - not working""*

end

output::

123124125126127

where desired output is::

123

124

125

126

127

[Walter Roberson]

In your fopen() statement, change the 'w' to 'wt'

[Sayak]

Ok, done. Thanks.