Need Code for Median Filtering on Color images
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Jagadeesh
colordigital image processingdoit4mefilterimage processing
clc; % Clear command window.
clear; % Delete all variables.
close all; % Close all figure windows except those created by imtool.
imtool close all; % Close all figure windows created by imtool.
workspace; % Make sure the workspace panel is showing.
fontSize = 15;% Read in a standard MATLAB color demo image.
folder = fullfile(matlabroot, '\toolbox\images\imdemos');baseFileName = 'peppers.png';% Get the full filename, with path prepended.
fullFileName = fullfile(folder, baseFileName);if ~exist(fullFileName, 'file') % Didn't find it there. Check the search path for it.
fullFileName = baseFileName; % No path this time.
if ~exist(fullFileName, 'file') % Still didn't find it. Alert user.
errorMessage = sprintf('Error: %s does not exist.', fullFileName); uiwait(warndlg(errorMessage)); return; endendrgbImage = imread(fullFileName);% Get the dimensions of the image. numberOfColorBands should be = 3.
[rows columns numberOfColorBands] = size(rgbImage);% Display the original color image.
subplot(3, 4, 1);imshow(rgbImage);title('Original color Image', 'FontSize', fontSize);% Enlarge figure to full screen.
set(gcf, 'Position', get(0,'Screensize')); % Extract the individual red, green, and blue color channels.
redChannel = rgbImage(:, :, 1);greenChannel = rgbImage(:, :, 2);blueChannel = rgbImage(:, :, 3);% Display the individual red, green, and blue color channels.
subplot(3, 4, 2);imshow(redChannel);title('Red Channel', 'FontSize', fontSize);subplot(3, 4, 3);imshow(greenChannel);title('Green Channel', 'FontSize', fontSize);subplot(3, 4, 4);imshow(blueChannel);title('Blue Channel', 'FontSize', fontSize);% Generate a noisy image. This has salt and pepper noise independently on
% each color channel so the noise may be colored.
noisyRGB = imnoise(rgbImage,'salt & pepper', 0.05);subplot(3, 4, 5);imshow(noisyRGB);title('Image with Salt and Pepper Noise', 'FontSize', fontSize);% Extract the individual red, green, and blue color channels.redChannel = noisyRGB(:, :, 1);greenChannel = noisyRGB(:, :, 2);blueChannel = noisyRGB(:, :, 3);% Display the noisy channel images.
subplot(3, 4, 6);imshow(redChannel);title('Noisy Red Channel', 'FontSize', fontSize);subplot(3, 4, 7);imshow(greenChannel);title('Noisy Green Channel', 'FontSize', fontSize);subplot(3, 4, 8);imshow(blueChannel);title('Noisy Blue Channel', 'FontSize', fontSize);% Median Filter the channels:
redMF = medfilt2(redChannel, [3 3]);greenMF = medfilt2(greenChannel, [3 3]);blueMF = medfilt2(blueChannel, [3 3]);% Find the noise in the red.
noiseImage = (redChannel == 0 | redChannel == 255);% Get rid of the noise in the red by replacing with median.
noiseFreeRed = redChannel;noiseFreeRed(noiseImage) = redMF(noiseImage);% Find the noise in the green.
noiseImage = (greenChannel == 0 | greenChannel == 255);% Get rid of the noise in the green by replacing with median.
noiseFreeGreen = greenChannel;noiseFreeGreen(noiseImage) = greenMF(noiseImage);% Find the noise in the blue.
noiseImage = (blueChannel == 0 | blueChannel == 255);% Get rid of the noise in the blue by replacing with median.
noiseFreeBlue = blueChannel;noiseFreeBlue(noiseImage) = blueMF(noiseImage);% Reconstruct the noise free RGB image
rgbFixed = cat(3, noiseFreeRed, noiseFreeGreen, noiseFreeBlue);subplot(3, 4, 9);imshow(rgbFixed);title('Restored Image', 'FontSize', fontSize);
clc; % Clear the command window.
close all; % Close all figures (except those of imtool.)
imtool close all; % Close all imtool figures if you have the Image Processing Toolbox.
clear; % Erase all existing variables. Or clearvars if you want.
workspace; % Make sure the workspace panel is showing.
format long g;format compact;fontSize = 13;% Check that user has the Image Processing Toolbox installed.
hasIPT = license('test', 'image_toolbox');if ~hasIPT % User does not have the toolbox installed.
message = sprintf('Sorry, but you do not seem to have the Image Processing Toolbox.\nDo you want to try to continue anyway?'); reply = questdlg(message, 'Toolbox missing', 'Yes', 'No', 'Yes'); if strcmpi(reply, 'No') % User said No, so exit.
return; endend% Read in a standard MATLAB color demo image.
folder = 'D:\Temporary stuff';baseFileName = 'moogseed5.jpg';% Get the full filename, with path prepended.
fullFileName = fullfile(folder, baseFileName);if ~exist(fullFileName, 'file') % Didn't find it there. Check the search path for it.
fullFileName = baseFileName; % No path this time.
if ~exist(fullFileName, 'file') % Still didn't find it. Alert user.
errorMessage = sprintf('Error: %s does not exist.', fullFileName); uiwait(warndlg(errorMessage)); return; endendrgbImage = imread(fullFileName);% Get the dimensions of the image. numberOfColorBands should be = 3.
[rows, columns, numberOfColorBands] = size(rgbImage);% Display the original color image.
subplot(2, 3, 1);imshow(rgbImage);title('Original Color Image', 'FontSize', fontSize);% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);% Get the dimensions of the image.
% numberOfColorBands should be = 3 for an RGB image.
[rows, columns, numberOfColorBands] = size(rgbImage);if numberOfColorBands > 1 % Convert it to gray scale by taking only the green channel.
% The green channel will have the highest contrast for these green seeds.
grayImage = rgbImage(:, :, 2); % Take green channel.
end% Display the original green channel gray scale image.
subplot(2, 3, 2);imshow(grayImage, []);title('Green Channel Image', 'FontSize', fontSize);% Enlarge figure to full screen.set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]);% Give a name to the title bar.
set(gcf, 'Name', 'Demo by ImageAnalyst', 'NumberTitle', 'Off') % Let's compute and display the histogram.
[pixelCount, grayLevels] = imhist(grayImage);subplot(2, 3, 3); bar(grayLevels, pixelCount);grid on;title('Histogram of Green Channel', 'FontSize', fontSize);xlim([0 grayLevels(end)]); % Scale x axis manually.
% Create a binary image via thresholding.
binaryImage = grayImage > 55;% Display the image.
subplot(2, 3, 4);imshow(binaryImage, []);title('Binary Image', 'FontSize', fontSize);% Clean up.
binaryImage = imclearborder(binaryImage);binaryImage = imfill(binaryImage, 'holes');binaryImage = bwareaopen(binaryImage, 500);% Display the image.subplot(2, 3, 5);imshow(binaryImage, []);title('Cleaned Binary Image', 'FontSize', fontSize);% Mask the RGB image using bsxfun() function
maskedRgbImage = bsxfun(@times, rgbImage, cast(binaryImage, class(rgbImage)));% Display the image.subplot(2, 3, 6);imshow(maskedRgbImage, []);title('Masked RGB Image', 'FontSize', fontSize);
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