how to insert noise and save multiple images in different folders using a loop?(matlab)

Question

I am new in image processing and I want help. I have a folder (dataset) that contains 1000 images and I want to insert noise 'salt & pepper' with different density noise (0.01,0.02 and 0.03) , I used this line to do this:

 im = imread('C:\Users\SAMSUNG\Desktop\AHTD3A0002_Para1.tif');
 J = imnoise(im,'salt & pepper',0.01);

Please help me to do this : I want to save the result in 3 folder ( data1 contains images after noise with d=0.01, data2 contains images after noise with d=0.02 and data3 contains images after noise with d=0.03).

any suggestation and thanks in advance

obchardon · Answer 1 · 2016-05-20T13:51:42.807

1

An easy solution with 2 for loop.

%save the noise parameter.
noise = [0.01,0.02,0.03];

for i = 1:1000

%we generate the filename (you can adapt this code)
imname = fullfile('C:\Users\SAMSUNG\Desktop\',sprintf('AHTD3A0002_Para%d.tif',i))
%read the image.
im = imread(imname);

for j = 1:length(noise)

%apply the noise
J = imnoise(im,'salt & pepper',noise(j));
%save image in the right folder
imwrite(J,fullfile('C:\Users\SAMSUNG\Desktop',sprintf('folder%d',j)));

end
end

edited May 20 '16 at 13:51

answered May 20 '16 at 13:05

obchardon

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'Error: File: test.m Line: 17 Column: 77 Unbalanced or unexpected parenthesis or bracket'. – yosra May 20 '16 at 13:28
I haven't tested my code, but... you just have to count the number of parenthesis to correct the error,... try also to think by yourself. by the way I added a parenthesis. – obchardon May 20 '16 at 13:30
Error using imwrite (line 426) Unable to determine the file format from the filename. Error in test (line 18) imwrite(J,fullfile('C:\Users\SAMSUNG\Desktop\',sprintf('folder%f',noise(j)))); – yosra May 20 '16 at 13:40
1

I edited my answer but the answer is an example, you need to adjust the code for what you want – obchardon May 20 '16 at 13:52

Lati · Accepted Answer · 2016-05-30T06:41:29.793

Following code will allow you to select the folder and create the noised pictures in 3 different folders. It will only select the '*.tif' files which you can modify in the code. And if you need to create more noise levels, create a loop to name the folders and files dynamically.

% get dir
folderX = uigetdir();

% get files
picFiles = dir('*.tif');

% loop over the files and save them with the noise
for ii = 1:length(picFiles)

    currentIm = imread([folderX, '\', picFiles(ii).name]);

    % create folders if not exist
    if ~exist([folderX,'\noise_0.01\'], 'dir')
        % create folders
        mkdir([folderX,'\noise_0.01\']);
    end
    if ~exist([folderX,'\noise_0.02\'], 'dir')
        % create folders
        mkdir([folderX,'\noise_0.02\']);
    end
    if ~exist([folderX,'\noise_0.03\'], 'dir')
        % create folders
        mkdir([folderX,'\noise_0.03\']);
    end   

    J1 = imnoise(currentIm,'salt & pepper',0.01);       
    imwrite(J1,fullfile([folderX, '\noise_0.01\', picFiles(ii).name]));    

    J2 = imnoise(currentIm,'salt & pepper',0.02);    
    imwrite(J2,fullfile([folderX, '\noise_0.02\', picFiles(ii).name]));

    J3 = imnoise(currentIm,'salt & pepper',0.03);
    imwrite(J3,fullfile([folderX, '\noise_0.03\', picFiles(ii).name]));

end

how to insert noise and save multiple images in different folders using a loop?(matlab)

2 Answers2