How can i save images at the end of every iteration?

I have a code in which I am taking images from 2 different folders, processing it according to my need and trying to save the output of every iteration in a separate folder. But as I try to save the file with the help of imwrite command, I am getting the following error:

Unable to open file "Img.jpg" for writing. You might not have write permission.

I tried using different formats of images. I also tried fullfile, sprintf but its still giving the same error.

Here's the code:

raw_folder = 'C:\raw';
back_folder = 'C:\background';
raw_filename = dir(fullfile(raw_folder,'*.tif'))
back_filename = dir(fullfile(back_folder,'*.tif'))
total = numel(raw_filename)

for n = 1:total
    r = fullfile(raw_folder, raw_filename(n).name);
    b = fullfile(back_folder, back_filename(n).name);
    R = imread(r);
    B = imread(b);
    %---------------------------------------------------
    % Some code.....
    %---------------------------------------------------
    figure;imagesc(out,[50 60]);
    colormap(jet(255));
    
    fileLoc = 'C:\newcolor';
    fname = fullfile(fileLoc, strcat('Image',num2str(n),'.jpg'));
    imwrite(out,fname,'jpg');
    
%     path = 'C:\color';
%     imwrite(out,fullfile(path,strcat(num2str(i),'.jpg')));

    %---------------------------------------------------
end

How should I modify this code? Thank you.

[Rik]

What happens if you try fopen with and without an extension?

clc
[fileID,errmsg] = fopen(fullfile(fileLoc,'test'));
if fileID<0,error(errmsg),else,fclose(fileID);end
[fileID,errmsg] = fopen(fullfile(fileLoc,'test.txt'));
if fileID<0,error(errmsg),else,fclose(fileID);end
fprintf('Matlab has write permission in %s\n',fileLoc)

[Khushi Patni]

Error is when i try to save image using imwrite.

[Rik]

And the code I posted tries to determine if Matlab can write in that folder at all.

[Khushi Patni]

I am getting this error: No such file or directory

Answer 1

[Image Analyst]

Try it this way:

% By Image Analyst
clc;    % Clear the command window.
clearvars;
close all;  % Close all figures (except those of imtool.)
workspace;  % Make sure the workspace panel is showing.
fontSize = 20;
format compact;

raw_folder = pwd; %'C:\raw';
back_folder = pwd; %'C:\background';
raw_filename = dir(fullfile(raw_folder,'*.tif'))
back_filename = dir(fullfile(back_folder,'*.tif'))
numRawFiles = numel(raw_filename)

outputFolder = fullfile(raw_folder, 'Output');
if ~isfolder(outputFolder)
	fprintf('Creating new folder for output called "%s".\n', outputFolder);
	mkdir(outputFolder);
end

for n = 1:numRawFiles
	inputFileName = fullfile(raw_folder, raw_filename(n).name);
	backgroundFileName = fullfile(back_folder, back_filename(n).name);
	R = imread(inputFileName);
	B = imread(backgroundFileName);
	%---------------------------------------------------
	% Some code.....
	out = R;
	%---------------------------------------------------
	hFig = figure;
	imagesc(out,[50 60]);
	colormap(jet(255));
	drawnow;
	
	%---------------------------------------------------
	baseFileName = sprintf('Image %2.2d.png', n); % Don't use JPG - use PNG instead.
	fullOutputFileName = fullfile(outputFolder, baseFileName);
	fprintf('Writing out "%s"\n', fullOutputFileName);
	imwrite(out, fullOutputFileName);
	% Delete figure
	close(hFig);
end

[Khushi Patni]

Creating new folder for output called "C:\raw\Output".

Writing out "C:\raw\Output\Image -01.pngImage -9.99e-01.pngImage -9.98e-01.pngImage -9.97e-01.pngImage -9.96e-01.pngImage -9.95e-01.pngImage -9.94e-01.pngImage -9.93e-01.pngImage -9.92e-01.pngImage -9.91e-01.pngImage -9.90e-01.pngImage -9.89e-02.pngImage 8.65e-02.pngImage 8.74e-02.pngImage 8.84e-02.pngImage 8.94e-02.png ..........

Image 7.20e-01.... Output truncated. Text exceeds maximum line length for Command Window display.

Error using imwrite (line 548)

Unable to open file "C:\raw\Output\Image -01.pngImage-9.99e-01.pngImage -9.98e-01.pngImage -9.97e-01.pngImage -9.96e-01.pngImage -9.95e-01.png ........

Image 01.png" for writing. You might not have write permission.

Error in process_output (line 76)

imwrite(out, fullOutputFileName);

Getting the same error.

[Rik]

The only way I can see why that would happen is if n is a vector. What is the exact code you're using?

[Khushi Patni]

Yes you are correct. I checked the value of n and it is a vector of dimension 1x2048 containing the values which are getting printed when an image is being written.

[Khushi Patni]

Thankyou so much for your help the problem was with the vector n! Thankyou all!

[Image Analyst]

@Khushi Patni in the code you showed, n was not a vector, but then you did leave out some code where maybe you reassigned n. You should not reassign the loop iterator variable inside a loop. It will use it with your new value but once the loop starts again, it will ignore your change. My code did not have n as a vector. So, if we're done here, could you "Accept this answer"? Thanks in advance.

[Khushi Patni]

Yes. You are right! Thankyou!

Answer 2

[Image Analyst]

Try this:

fileLoc = 'E:\Internship\SAMEER\dataset\CONTROLLED\advanced\newcolor';
if ~isfolder(fileLoc)
    fprintf('Creating new folder called "%s".\n', fileLoc);
    mkdir(fileLoc);
end

[Khushi Patni]

Unable to open file "C:\newcolor\Image-1 -0.99902

-0.99805 -0.99707 -0.99609 -0.99511 -0.99414 -0.99316 -0.99218 -0.99121

-0.99023 -0.98925 -0.98828 -0.9873 -0.98632 -0.98534 -0.98437 -0.98339 .........

1.jpg" for writing. You might not have write permission.

Still giving this as the error.

[Image Analyst]

Your name is all messed up. Try this:

fileLoc = 'C:\newcolor';
if ~isfolder(fileLoc)
    fprintf('Creating new folder called "%s".\n', fileLoc);
    mkdir(fileLoc);
end
baseFileName = sprintf('Image %2.2d.png', n); % Don't use JPG - use PNG instead.
fullFileName = fullfile(fileLoc, baseFileName);
fprintf('Writing out "%s"\n', fullFileName);
imwrite(out, fullFileName);

[Khushi Patni]

Error using imwrite

Unable to open file "C:\newcolor\Image -01.pngImage

-9.99e-01.pngImage -9.98e-01.pngImage -9.97e-01.pngImage -9.96e-01.pngImage -9.95e-01.pngImage

-9.94e-01.pngImage -9.93e-01.pngImage -9.92e-01.pngImage -9.91e-01.png...........

Image 01.png" for writing. You might not have write permission.

The same error is displayed.

[Khushi Patni]

Any other way to go about it?

[Rik]

Why did you change your code so that n is a vector with non-integer values, but didn't say anything about what code you were using?

[Image Analyst]

See code in my other answer I posted earlier today.