How to fullfill segmented region by using region growing?

Can anyone help me on how to make the segmented purple region fulfilled the neighborhood 'empty' area with the same purple color?

The image is actually an overlapped of two brain images: </matlabcentral/answers/uploaded_files/54479/overlapped%20images.png>

The problem is, how to make the region of purple growing and fulfill all it's neighborhood region so that the region is larger.

Actually my intention is to perform region growing before k-means clustering, but it seems like it does not make any sense because both are segmentation. Any idea guys?...

Answer 1

[iza]

The image is actuall

y an overlapped of two brain images:

[iza]

I managed to solve the problem using this code:

% Find boundry of image

bw = im2bw(image, graythresh(image));

cc = bwconncomp(bw);

lblMatrix = labelmatrix(cc);

edgeMatrix=edge(lblMatrix,'roberts',0);

edgeMatrix1 = double(edgeMatrix);

edgeMatrix1(end, end, 3) = 0;

figure;

imshow(edgeMatrix1);

%fill inside the region of detected edge

edgeMatrix2=imfill (edgeMatrix1,'holes');

figure; imshow(edgeMatrix2); title('WM and WMH Boundary Extraction','FontSize', 12);

%overlay detected edge on segmented image

rgbImageX = imoverlay(hat, edgeMatrix1, [1 0 0]);

imshow(rgbImageX); title('Boundary overlay on segmented images','FontSize', 12);

[iza]

In order to crop the image by using the boundary, here is the code. By the way addImGMWM is RGB image.

%crop the image

% Create a binary image ("mask") from the ROI object.

figure;

imshow(bw);

title('Binary mask of the region', 'FontSize', fontSize);

% Mask the image.

rgbImage=addImGMWM;

maskedRgbImage = bsxfun(@times, rgbImage, cast(bw,class(rgbImage)));

% Display it.

figure;

imshow(maskedRgbImage);

title('Mask of the desired region only', 'FontSize', fontSize);