Image processing code Help

NEED help to use imread for 20 images together. This code can work on 1 image at a time i want to use this code for all 20 images at once and want to save all images in one new folder after processing .Please can anyone help me to modify this code.

RGB=imread('1.jpg'); 
% input 768*576 pixel uint8 type true color image.
R=RGB(:,:,1); 
% red surface image extraction
G=RGB(:,:,2); 
B=RGB(:,:,3); 
figure; 
imshow(RGB) 
title('original image'); 
% create a new empty graphics window
% view images
figure, 
imshow(R) 
title('red face version'); 
figure, 
imshow(G) 
title('green face version'); 
figure, 
imshow(B)  

[Geoff Hayes]

Anas - are all 20 files in the same folder? Which new image do you want to save to file - the extracted red, green or blue images? Where should the new files be saved to and what should their new names be?

[Anas Bilal]

all are images are in same golder. green red an dblue att want to save. names can img1 red, img2 green, img3 blue,....till 20. Images can save in "D:\First"

[Anas Bilal]

Image type is .jpg

Answer 1

[Ameer Hamza]

See my answer here related to batch processing of csv files: https://www.mathworks.com/matlabcentral/answers/509790-read-and-manipulate-multiple-csv-files

Here is a general structure of the code

files = dir('*.jpg'); % get name of all files with jpg extension

for i=1:numel(files) % run the for loop over all images
    name = files(i).name; % get name of i-th image file
    img = imread(name); % load the image
    R=RGB(:,:,1); 
    % red surface image extraction
    G=RGB(:,:,2); 
    B=RGB(:,:,3);
    imwrite(R, ['img' num2str(i) ' red.jpg']);
    imwrite(G, ['img' num2str(i) ' green.jpg']);
    imwrite(B, ['img' num2str(i) ' blue.jpg']);
end

This link also provide helpful information: https://matlab.fandom.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

[Anas Bilal]

Not working

Can you please update my code accordingly.

all are images are in same golder. green red an dblue att want to save. names can img1 red, img2 green, img3 blue,....till 20. Images can save in "D:\First"

Image tyep .jpg

[Ameer Hamza]

Check the updated code. It will save each channel in a separate file. Since you are saving a single channel, the actual image will appear gray.

[Anas Bilal]

still not working

[Ameer Hamza]

What is the error?

[Anas Bilal]

Its working Thank you

[Ameer Hamza]

Glad to be of help.

[Anas Bilal]

I am facing one problem the code is working but it take just one picture and loop is not working. just one picture is preprocessed multiple times. it didn't pick the pictures in order just pick first picture and run it for multiple time.

[Anas Bilal]

eg picture name are

image001.png

image002.png

image003.png

.

...

.

.

.

.

.

.

image400.png

[Ameer Hamza]

Can you paste your code?

[Anas Bilal]

files = dir('*.ppm'); % get name of all files with jpg extension
for i=1:numel(files) % run the for loop over all images
    name = files(i).name; % get name of i-th image file
    img = imread(name); % load the image
    R=RGB(:,:,1); 
    % red surface image extraction
    G=RGB(:,:,2); 
    B=RGB(:,:,3);
    imwrite(RGB, ['img' num2str(i) ' RGB.tif']);
    imwrite(R, ['img' num2str(i) ' red.tif']);
    imwrite(G, ['img' num2str(i) ' green.tif']);
    imwrite(B, ['img' num2str(i) ' blue.tif']);
    %histogram equivilzation of Green Channel
 b=adapthisteq(G); 
%Two times limited contrast adaptive direct equalization

ba=adapthisteq(b); 

% adjusts contrast in grayscale images.
% increases
      %figure; 
      imshow(ba) 
      title('enhanced contrast') 
      imwrite(ba, ['img' num2str(i) ' ba.tif']);
end

[Anas Bilal]

my images extension are .ppm and i want to save them as .tif

[Ameer Hamza]

I couldn't find an issue in the for loop. Can you add a breakpoint in your code and see if the loop is running once or 400 times for each image?

[Anas Bilal]

its run 400 time on a on 1 image and didn't use loop. just run for 1 image and then stop.

[Ameer Hamza]

What is the value of variable 'name' in each iteration? Does it get changed or remain same?

[Anas Bilal]

its run 400 time on a on 1 image and didn't use loop. just run for 1 image and then stop.

[Image Analyst]

Anas, it can't run 400 times on one image without using a loop, unless you had the cope copied 400 times, which I very much doubt. Most likely what happened is you didn't properly get the filename at the top of the loop. You didn't use the index and just got the same filename over and over again.

[Anas Bilal]

can you share your code.

[Ameer Hamza]

Anas, your code is correct. Can you show us the output after running these two lines?

files = dir('*.ppm');
numel(files)

[Image Analyst]

Anas: I've corrected your code. This works. Just uncomment the imwrite() lines:

folder = pwd; % Whever you want...
filePattern = fullfile(folder, '*.ppm');
files = dir(filePattern); % get name of all files with jpg extension
if numel(files) == 0
	warningMessage = sprintf('No files found in folder\n%s.\n', folder);
	fprintf('%s\n', warningMessage);
	beep;
	uiwait(errordlg(warningMessage));
	return;
end
numberOfImageFiles = length(files)
for k = 1 : numberOfImageFiles % run the for loop over all images
	baseFileName = files(k).name; % get name of i-th image file
	fullFileName = fullfile(folder, baseFileName);
	fprintf('Reading in file %d of %d : %s\n', k, numberOfImageFiles, fullFileName);
	img = imread(fullFileName); % load the image
	subplot(1, 2, 1);
	imshow(img);
	caption = sprintf('Original Image :\n%s', baseFileName);
	title(caption, 'FontSize', 15, 'Interpreter', 'none');
	
	[rows, columns, numberOfColorChannels] = size(img);
	if numberOfColorChannels == 3
		R = img(:, :, 1);	% Red channel image extraction
		G = img(:, :, 2);
		B = img(:, :, 3);

		% Write out RGB image as TIFF format.
		outputBaseFileName = sprintf('img %d RGB.tif', k);
		outputFullFileName = fullfile(folder, outputBaseFileName);
		fprintf('      Writing file %s\n', outputFullFileName);
% 		imwrite(R, outputFullFileName);

		% Write out red image as TIFF format.
		outputBaseFileName = sprintf('img %d red.tif', k);
		outputFullFileName = fullfile(folder, outputBaseFileName);
		fprintf('      Writing file %s\n', outputFullFileName);
% 		imwrite(R, outputFullFileName);

		% Write out green image as TIFF format.
		outputBaseFileName = sprintf('img %d green.tif', k);
		outputFullFileName = fullfile(folder, outputBaseFileName);
		fprintf('      Writing file %s\n', outputFullFileName);
% 		imwrite(R, outputFullFileName);

		% Write out blue image as TIFF format.
		outputBaseFileName = sprintf('img %d blue.tif', k);
		outputFullFileName = fullfile(folder, outputBaseFileName);
		fprintf('      Writing file %s\n', outputFullFileName);
% 		imwrite(R, outputFullFileName);
	else
		% img is already a gray scale image.
		G = img;
	end
	
	% Histogram equivilzation of Green Channel
	b=adapthisteq(G);
	% Two times limited contrast adaptive direct equalization	
	ba=adapthisteq(b);
	
	% adjusts contrast in grayscale images.
	subplot(1, 2, 2);
	imshow(ba)
	title('Enhanced contrast', 'FontSize', 15, 'Interpreter', 'none');
	outputBaseFileName = sprintf('img %d enhanced.tif', k);
	outputFullFileName = fullfile(folder, outputBaseFileName);
	fprintf('      Writing file %s\n', outputFullFileName);
% 	imwrite(ba, outputFullFileName);
	drawnow;
	pause(0.5);
end

[Anas Bilal]

Great work thank you very much .