MATLAB: Blurring/Filling in color on jpeg image.

digital image processingImage Processing Toolboximfillmorphological closingshading

Hi,

I'm working with painmaps (see example attached), and I'm trying to shade in the red areas. As you can see the red is scribbled on and there are white spaces within, I'd like to take the outer extremities of the red scribbling and fill in everything inside of it red, so that it's one solid block of red. This is so that I can quantify the shaded pixels for analytical purposes. Any help with this would be much appreciated. I was thinking that perhaps imfill or morphological closing could be used, but I'm struggling to make either option work.

Thanks, Matt

Best Answer

You need to do some steps like I showed you before to get the red scribbles. Then you need to call activecontour() to get the "envelope" of the red scribbles. See attached demo.

Related Solutions

MATLAB: Segment Image based on Color pixels.

Try this:

clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 16;
%===============================================================================
% Get the name of the image the user wants to use.
baseFileName = 'A1.jpg';
folder = pwd;
fullFileName = fullfile(folder, baseFileName);
% Check if file exists.
if ~exist(fullFileName, 'file')
	% The file doesn't exist -- didn't find it there in that folder.
	% Check the entire search path (other folders) for the file by stripping off the folder.
	fullFileNameOnSearchPath = baseFileName; % No path this time.
	if ~exist(fullFileNameOnSearchPath, 'file')
		% Still didn't find it.  Alert user.
		errorMessage = sprintf('Error: %s does not exist in the search path folders.', fullFileName);
		uiwait(warndlg(errorMessage));
		return;
	end
end
%=======================================================================================
% Read in demo image.
rgbImage = imread(fullFileName);
% Get the dimensions of the image.
[rows, columns, numberOfColorChannels] = size(rgbImage)
% Display image.
subplot(2, 2, 1);
imshow(rgbImage, []);
impixelinfo;
axis on;
caption = sprintf('Original Color Image\n%s', baseFileName);
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.
% Set up figure properties:
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0.05 1 0.95]);
% Get rid of tool bar and pulldown menus that are along top of figure.
% set(gcf, 'Toolbar', 'none', 'Menu', 'none');
% Give a name to the title bar.
set(gcf, 'Name', 'Demo by ImageAnalyst', 'NumberTitle', 'Off')
drawnow;
% Extract the individual red, green, and blue color channels.
redChannel = rgbImage(:, :, 1);
greenChannel = rgbImage(:, :, 2);
blueChannel = rgbImage(:, :, 3);
% get a mask for the red line.
mask = redChannel > greenChannel;
% Display the image.


subplot(2, 2, 2);
imshow(mask);
caption = sprintf('Color Segmentation Mask Image');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
impixelinfo;
axis('on', 'image');
drawnow;
% fill holes.
mask = imfill(mask, 'holes');
% Take the largest blob only.
mask = bwareafilt(mask, 1);
% Shrink two layers of pixels to come inside the red lines.
mask = imerode(mask, true(5));
% Display the image.
subplot(2, 2, 3);
imshow(mask);
title('Final Mask', 'FontSize', fontSize, 'Interpreter', 'None');
impixelinfo;
axis('on', 'image');
% Get a masked image.
% Mask the image using bsxfun() function to multiply the mask by each channel individually.
maskedRgbImage = bsxfun(@times, rgbImage, cast(mask, 'like', rgbImage));
% Display the image.
subplot(2, 2, 4);
imshow(maskedRgbImage);
title('Masked RGB Image', 'FontSize', fontSize, 'Interpreter', 'None');
impixelinfo;
axis('on', 'image');
% Tell user the answer.
message = sprintf('Done!');
uiwait(helpdlg(message));

MATLAB: Read three different RGB band and Swap the Band

Try this:

% Extract the individual red, green, and blue color channels.
redChannel = rgbImage(:, :, 1);
greenChannel = rgbImage(:, :, 2);
blueChannel = rgbImage(:, :, 3);
% Now swap around in any way you want.
newRedChannel = greenChannel;
newGreenChannel = blueChannel; 
newBlueChannel = redChannel;
% Recombine separate color channels into a single, true color RGB image.
NewRgbImage = cat(3, newRedChannel, newGreenChannel, newBlueChannel);

Best Answer

Related Solutions

MATLAB: Segment Image based on Color pixels.

MATLAB: Read three different RGB band and Swap the Band

Related Question