Having issue with imwrite. I'm attaching my code and error below.

% Apply normalization to images
    nim=minMaxNormalize(oim);
   % Save the image according to five fold set in respective tumor folder. After processing the whole dataset, take set1 as testing (testDS1) 
   %and remainig four sets as traing (trainingDS1). apply similar method for set2, set3, set4, and set5
    % Set1
    if cvind(i)==1   
	if imlab==1
        outputFileName = fullfile('/Users/ragib/Desktop/Thesis/MatlabCodes/set1/meningioma/', [num2str(i) '.jpg']);
        imwrite(nim, outputFileName);
    	elseif imlab==2
        outputFileName = fullfile('/Users/ragib/Desktop/Thesis/MatlabCodes/set1/glioma/', [num2str(i) '.jpg']);
        imwrite(nim, outputFileName);
   	elseif imlab==3
        outputFileName = fullfile('/Users/ragib/Desktop/Thesis/MatlabCodes/set1/pituitary/', [num2str(i) '.jpg']);
        imwrite(nim, outputFileName);
    	else 
        fprintf('No label found');
    	end                  
    end

Answer 1

[Image Analyst]

My guesses are either that the file is probably open and locked in some other program when you try to blast over it, and so it won't let you.

By the way, what is the value of i? You should not use i as a variable since it's the imaginary variable. Use k or index or something else.

Also, do not use JPG format if you're doing image analysis. Use PNG instead. PNG is lossless compression and is pretty much the de facto standard these days while (the hated) JPG often gives bad compression artifacts. There will be no change to image values in a round trip save/recall using PNG like there will be with JPG.

[Shah Isha Redohy]

clc;
clear all;
clear all;
close all;
% Download CE-MRI dataset available at (https://figshare.com/articles/brain_tumor_dataset/1512427). 
% Make a folder imageData and put all .mat file in it 
% Load five fold cross validation index file
load cvind5fold.mat
% Read the images data
for i = 1 : 3064
    % load image data from mat file and read image and label
    load(['C:\Users\Zar Nawab Khan Swati\Documents\MATLAB\imageData\', num2str(i), '.mat']);
    oim=cjdata.image;
    imlab=cjdata.label;
% Apply normalization to images
    nim=minMaxNormalize(oim);
   % Save the image according to five fold set in respective tumor folder. After processing the whole dataset, take set1 as testing (testDS1) 
   %and remainig four sets as traing (trainingDS1). apply similar method for set2, set3, set4, and set5
    % Set1
    if cvind(i)==1   
	if imlab==1
        outputFileName = fullfile('C:\Users\Zar Nawab Khan Swati\Documents\MATLAB\MRI_Cancer_database\set1\meningioma\', [num2str(i) '.jpg']);
        imwrite(nim, outputFileName);
    	elseif imlab==2
        outputFileName = fullfile('C:\Users\Zar Nawab Khan Swati\Documents\MATLAB\MRI_Cancer_database\set1\glioma\', [num2str(i) '.jpg']);
        imwrite(nim, outputFileName);
   	elseif imlab==3
        outputFileName = fullfile('C:\Users\Zar Nawab Khan Swati\Documents\MATLAB\MRI_Cancer_database\set1\pituitary\', [num2str(i) '.jpg']);
        imwrite(nim, outputFileName);
    	else 
        fprintf('No label found');
    	end                  
    end

[Shah Isha Redohy]

This is the code I am working with. I am new on matlab so I don't have much idea whats going wrong here. I am trying to load data from a dataset and divided them in 5 sets. After performing normalization. I tried changing the - imwrite(nim, outputFileName); to this imwrite(nim, 'outputFileName.jpg'); Then I am getting one image saved but There are multiple images that need to saved in that folder.

[Simon Chan]

Did you create the folders before saving the images?

If not, try to add those lines before the loop.

On the other hand, as suggested by Image Analyst, please save the image as png instead of jpg format.

 
load cvind5fold.mat
% Create folders
% Suppose working directory is C:\Users\Zar Nawab Khan Swati\Documents\MATLAB
myFolder = pwd;                                
mkdir(fullfile(myFolder,'\MRI_Cancer_database\set1\meningioma'));
mkdir(fullfile(myFolder,'\MRI_Cancer_database\set1\glioma'));
mkdir(fullfile(myFolder,'\MRI_Cancer_database\set1\pituitary'));
 

[Walter Roberson]

I recommend

% Create folders
% Suppose working directory is C:\Users\Zar Nawab Khan Swati\Documents\MATLAB
myFolder = pwd;
MRI_dir = string(fullfile(myFolder,'MRI_Cancer_database'));
set1 = string(fullfile(MRI_dir, 'set1'));
men_dir = string(fullfile(set1, 'meningioma'));
gli_dir = string(fullfile(set1, 'glioma'));
pit_dir = string(fullfile(set1, 'pituitary'));
for D = [MRI_dir, set1, men_dir, gli_dir, pit_dir]
  if ~isfolder(D)
    try
       mkdir(D)
       fprintf('Created directory "%s"\n', D);
    catch ME
       error('Could not create folder "%s"', D);
    end
  end
end

[Shah Isha Redohy]

In which portion should i use the code ?

I use before the loop and above the 'if cvind(i)=1'

It showing this error-

Error using fullfile (line 51)
String input not supported.
Error in Five_Fold_valid_MRI_Dataset (line 12)
set1 = string(fullfile(MRI_dir, 'set1')); 

[Shah Isha Redohy]

it's working now. Thank your everyone for helping.

[Walter Roberson]

You marked that you are using R2021a, but line 51 of fullfile() for R2021a cannot generate any error. Line 51 of fullfile for R2021a is

containsCellOrStringInput = false;

Either you are using a third-party fullfile(), or else you are using R2016b, which is a release in which string() datatype was first released but was not yet available in all functions (or you copied fullfile.m from an old release.)