You are now following this question
- You will see updates in your followed content feed.
- You may receive emails, depending on your communication preferences.
Image processing code Help
4 views (last 30 days)
Show older comments
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)
3 Comments
Geoff Hayes
on 16 Apr 2020
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
on 16 Apr 2020
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
on 16 Apr 2020
Image type is .jpg
Accepted Answer
Ameer Hamza
on 16 Apr 2020
Edited: Ameer Hamza
on 16 Apr 2020
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
20 Comments
Anas Bilal
on 16 Apr 2020
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
on 16 Apr 2020
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
on 16 Apr 2020
still not working
Ameer Hamza
on 16 Apr 2020
What is the error?
Anas Bilal
on 16 Apr 2020
Its working Thank you
Ameer Hamza
on 16 Apr 2020
Glad to be of help.
Anas Bilal
on 17 Apr 2020
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
on 17 Apr 2020
eg picture name are
image001.png
image002.png
image003.png
.
...
.
.
.
.
.
.
image400.png
Ameer Hamza
on 17 Apr 2020
Can you paste your code?
Anas Bilal
on 17 Apr 2020
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
on 17 Apr 2020
my images extension are .ppm and i want to save them as .tif
Ameer Hamza
on 17 Apr 2020
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
on 17 Apr 2020
its run 400 time on a on 1 image and didn't use loop. just run for 1 image and then stop.
Ameer Hamza
on 17 Apr 2020
What is the value of variable 'name' in each iteration? Does it get changed or remain same?
Anas Bilal
on 17 Apr 2020
its run 400 time on a on 1 image and didn't use loop. just run for 1 image and then stop.
Image Analyst
on 17 Apr 2020
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
on 17 Apr 2020
can you share your code.
Ameer Hamza
on 17 Apr 2020
Anas, your code is correct. Can you show us the output after running these two lines?
files = dir('*.ppm');
numel(files)
Image Analyst
on 17 Apr 2020
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
on 17 Apr 2020
Great work thank you very much .
More Answers (0)
See Also
Categories
Find more on Image Processing Toolbox in Help Center and File Exchange
Tags
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!An Error Occurred
Unable to complete the action because of changes made to the page. Reload the page to see its updated state.
Select a Web Site
Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .
You can also select a web site from the following list:
How to Get Best Site Performance
Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.
Americas
- América Latina (Español)
- Canada (English)
- United States (English)
Europe
- Belgium (English)
- Denmark (English)
- Deutschland (Deutsch)
- España (Español)
- Finland (English)
- France (Français)
- Ireland (English)
- Italia (Italiano)
- Luxembourg (English)
- Netherlands (English)
- Norway (English)
- Österreich (Deutsch)
- Portugal (English)
- Sweden (English)
- Switzerland
- United Kingdom (English)
Asia Pacific
- Australia (English)
- India (English)
- New Zealand (English)
- 中国
- 日本Japanese (日本語)
- 한국Korean (한국어)