Automatilly read image files and apply filtre in Matlab

I have a 10 different gray image files in current folder.

For example:

img1.jpg

img2.jpg

img3.jpg

img4.jpg

....

image10.jpg

This script automatilly read image files and apply smoothing filtre step by step using with for loop. This code script is feedback me .

For example: there are 10 image files in current folder

this files names: img1.jpg, img2.jpg, img3.jpg..........

So, it gives me names of files and total number of files.

This scpirt code apply smoothing filter for image1 from to image50 step by step

smoothing filter:

H= ones(3)/9;

result = filter2(H,image);

after that it save this files in same current folder with different names

For example:

outimg1.jpg

outimg2.jpg

outimg3.jpg

outimg4.jpg

.....

outimg10.jpg

I don't know how to do. If you help me, i will be very happy.

Answer 1

[Subhadeep Koley]

Hi, the below code snippet might help.

% "imagefiles" variable contails each file detail (e.g. filename, size, etc.)
imagefiles = dir(['pasteYourFolderPathHere\', '*.jpg']);
% Count total number of files
nfiles = length(imagefiles);
% Define filter kernel
filterKernel = ones(3)/9;
for idx = 1:nfiles
    currentfilename = [imagefiles(idx).folder , '\', imagefiles(idx).name];
    currentimage = imread(currentfilename);
    currentimage = im2double(currentimage);
    % Apply filter to current image     
    result = filter2(filterKernel, currentimage);
    % Save the filtered image     
    imwrite(uint8(rescale(result, 0, 255)),...
        ['pasteYourFolderPathHere\', 'out', imagefiles(idx).name, '.jpg'])
end

[Rooter Boy]

Sir thank you but it didn't work. It gives an error.

Error using conv2

N-D arrays are not supported.

Error in filter2 (line 59)

y = conv2(hcol, hrow, x, shape);

Error in aas (line 12)

result = filter2(filterKernel, currentimage);

>>

[Rooter Boy]

Sir, it works just .tif files.

I can show number of image files using with fprintf('%d\n', nfiles); but i don't know how to see names of files.

[Subhadeep Koley]

Hi, you're facing the error because your image files are 3 channel RGB image and filter2() function can only work on 2D grayscale images. You can use the convn() function to achive the same. convn() works on both RGB and grayscale images. I've also added the code to display total number and name of image files. Refer the code below.

% "imagefiles" variable contails each file detail (e.g. filename, size, etc.)
imagefiles = dir(['pasteYourFolderPathHere\', '*.jpg']);
% Count total number of files
nfiles = length(imagefiles);
% Display total number of the files
disp(['Total number of file: ', num2str(nfiles)])
% Define filter kernel
filterKernel = ones(3)/9;
for idx = 1:nfiles
    % Display name of each file
    disp(imagefiles(idx).name)
    currentfilename = [imagefiles(idx).folder , '\', imagefiles(idx).name];
    currentimage = imread(currentfilename);
    % Apply filter to current image using convn    
    result = convn(currentimage, filterKernel, 'same');
    % Save the filtered image     
    imwrite(uint8(result),...
        ['pasteYourFolderPathHere\', 'out', imagefiles(idx).name, '.jpg'])
end