How do I select only 100 images in a folder of 200 images, according to a list of 100 different names ?

Hello,

I have a list of 100 different pictures.

I have the name of the 100 pictures, for instance :

bananas

strawberrys

etc

I want to select those 100 images in the folder in which there are 200 images in total.

I can do this by hand, but does anyones have an idea of code to do so ?

Thanks a lot

Answer 1

[Subhadeep Koley]

Assuming you have the required image names in a text file. Refer the code below.

myFolder = 'putYourFolderPathHere';
filePattern = fullfile(myFolder, '*.tiff'); % Change the extension according to your file extension
tiffFiles = dir(filePattern);
fid = fopen('fileNameList.txt', 'rt'); % Assuming fileNameList.txt contains the names of the required images
idx = 1;
while feof(fid) == 0
    tline = fgetl(fid);
    fileNamesToBeInc{idx} = tline;
    idx = idx+1;
end

for k = 1:length(tiffFiles)
    baseFileName = tiffFiles(k).name;
    for i = 1:length(fileNamesToBeInc)
        if strcmp(fileNamesToBeInc{i}, baseFileName)
            fullFileName = fullfile(myFolder, baseFileName);
            temp{k} = imread(fullFileName);
        end
    end
end
imageArray = temp(~cellfun('isempty',temp)); % imageArray contains your image files
% Display all the selected images
montage(imageArray);

[Solene Frileux]

Thanks a lot to you both

By temp in

temp{k} = imread(fullFileName)

Did you mean a function or is it an output new name ?

Because Matlab says

Unrecognized function or variable 'temp'.

Error in select_cent_images (line 24)
imageArray = temp(~cellfun('isempty',temp)); % imageArray contains your image files

Thanks

Solène

[Subhadeep Koley]

"temp" is just a variable name here.

However, I guess the programme could not find any matching pair between your filename list (in the .txt file) and filenames (actual name of the files in the disk). Therefore, this

if strcmp(fileNamesToBeInc{i}, baseFileName) 

line never returned logical true and the variable "temp" is never created in the first place. And after the loop we are trying to access the "temp", which does not exists. This is the reason of the error.

Can you provide your .txt file? So that I can inspect

[Stephen23]

@Subhadeep Koley: you forgot to fclose the file after reading it. The variable temp should be preallocated before the loop to avoid class/size/missing variable errors. Using ismember would be simpler (and makes it trivial to check how many filenames match before trying to import the file data).

[Subhadeep Koley]

@Stephen Cobeldick: Yes sir, I have incorporated the changes. The updated code is below. Thanks!

myFolder = 'putYourFolderPathHere';
filePattern = fullfile(myFolder, '*.tiff'); % Change the extension according to your file extension
tiffFiles = dir(filePattern);
fid = fopen('fileNameList.txt', 'rt'); % Assuming fileNameList.txt contains the names of the required images
idx = 1;
while feof(fid) == 0
    tline = fgetl(fid);
    fileNamesToBeInc{idx} = tline;
    idx = idx+1;
end
fclose(fid);
temp = cell(1, length(fileNamesToBeInc));
idx = 1;
for k = 1:length(tiffFiles)
    baseFileName = tiffFiles(k).name;
    if ismember(baseFileName, fileNamesToBeInc)
        fullFileName = fullfile(myFolder, baseFileName);
        temp{idx} = imread(fullFileName);
        idx = idx + 1;
    end
end
imageArray = temp(~cellfun('isempty', temp)); % imageArray contains your image files

[Solene Frileux]

Thanks a lot to you both.

Everything works perfectly until the creation of temp, which cells are created but empty.

imageArray contains 1x0 cell

fullFileName does not seem to be created.

Here is my file .txt as asked.

Thanks again

[Subhadeep Koley]

Yes, because your text file only contains the name of the images without their extension (e.g., .jpeg, .tiff, .png, etc.). Use the code below which appends the extension after the filenames.

myFolder = 'putYourFolderPathHere';
filePattern = fullfile(myFolder, '*.tiff'); % Change the '*.tiff' extension according to your file extension
tiffFiles = dir(filePattern);
fid = fopen('images_cent_names.txt', 'rt'); % Assuming fileNameList.txt contains the names of the required images
idx = 1;
while feof(fid) == 0
    tline = fgetl(fid);
    fileNamesToBeInc{idx} = tline;
    idx = idx+1;
end
fclose(fid);
temp = cell(1, length(fileNamesToBeInc));
% Appending extension
for k = 1:length(fileNamesToBeInc)
    fileNamesToBeInc{k} = [fileNamesToBeInc{k}, '.tiff']; % Change the '.tiff' extension also according to your file extension
end
% Reading files
idx = 1;
for k = 1:length(tiffFiles)
    baseFileName = tiffFiles(k).name;
    if ismember(baseFileName, fileNamesToBeInc)
        fullFileName = fullfile(myFolder, baseFileName);
        temp{idx} = imread(fullFileName);
        idx = idx + 1;
    end
end
imageArray = temp(~cellfun('isempty', temp)); % imageArray contains your image files

Answer 2

[J Chen]

Use the folllwoing command to get a structure that contains file information

listing = dir('*.jpg');

Use the folllwoing command to load the image files

for i = 1:100
    A(i) = imread(listing(i).name);
end

[Solene Frileux]

Hello J Chen,

Thanks a lot for your answer.

I think I was not rpecise enough and the other answer is more adequate.

Indeed, I need to select a hundred pictures out of 200, from a file containing the 200, knowing I have a txt file where the names of the 100 pictures I want is written.

Thanks for your help,

Solène