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hi, I have following code In this code author is using ginput to select a particular area and then get the result, what my problem is that I want if there is more than one patch from image need to be extracted then what I can do, I try ginput(2) but it takes two inputs but did not extract the multiple regions, is there any trick that I can do here is the code and here is the image

function [P, J] = regionGrowing(cIM, initPos, thresVal, maxDist, tfMean, tfFillHoles, tfSimplify)

if nargin > 7

error('Wrong number of input arguments!')

end

if ~exist('cIM', 'var')

himage = findobj('Type', 'image');

if isempty(himage) || length(himage) > 1

error('Please define one of the current images!')

end

cIM = get(himage, 'CData');

end

if ~exist('initPos', 'var') || isempty(initPos)

himage = findobj('Type', 'image');

if isempty(himage)

himage = imshow(cIM, []);

end

% graphical user input for the initial position

p = ginput(1);

% get the pixel position concerning to the current axes coordinates

initPos(1) = round(axes2pix(size(cIM, 2), get(himage, 'XData'), p(2)));

initPos(2) = round(axes2pix(size(cIM, 1), get(himage, 'YData'), p(1)));

end

if ~exist('thresVal', 'var') || isempty(thresVal)

thresVal = double((max(cIM(:)) - min(cIM(:)))) * 0.05;

end

if ~exist('maxDist', 'var') || isempty(maxDist)

maxDist = Inf;

end

if ~exist('tfMean', 'var') || isempty(tfMean)

tfMean = false;

end

if ~exist('tfFillHoles', 'var')

tfFillHoles = true;

end

if isequal(ndims(cIM), 2)

initPos(3) = 1;

elseif isequal(ndims(cIM),1) || ndims(cIM) > 3

error('There are only 2D images and 3D image sets allowed!')

end

[nRow, nCol, nSli] = size(cIM);

if initPos(1) < 1 || initPos(2) < 1 ||...

initPos(1) > nRow || initPos(2) > nCol

error('Initial position out of bounds, please try again!')

end

if thresVal < 0 || maxDist < 0

error('Threshold and maximum distance values must be positive!')

end

if ~isempty(which('dpsimplify.m'))

if ~exist('tfSimplify', 'var')

tfSimplify = true;

end

simplifyTolerance = 1;

else

tfSimplify = false;

end

% initial pixel value

regVal = double(cIM(initPos(1), initPos(2), initPos(3)));

% text output with initial parameters

disp(['RegionGrowing Opening: Initial position (' num2str(initPos(1))...

'|' num2str(initPos(2)) '|' num2str(initPos(3)) ') with '...

num2str(regVal) ' as initial pixel value!'])

% preallocate array

J = false(nRow, nCol, nSli);

% add the initial pixel to the queue

queue = [initPos(1), initPos(2), initPos(3)];

%%%START OF REGION GROWING ALGORITHM

while size(queue, 1)

% the first queue position determines the new values

xv = queue(1,1);

yv = queue(1,2);

zv = queue(1,3);

% .. and delete the first queue position

queue(1,:) = [];

% check the neighbors for the current position

for i = -1:1

for j = -1:1

for k = -1:1

if xv+i > 0 && xv+i <= nRow &&... % within the x-bounds?

yv+j > 0 && yv+j <= nCol &&... % within the y-bounds?

zv+k > 0 && zv+k <= nSli &&... % within the z-bounds?

any([i, j, k]) &&... % i/j/k of (0/0/0) is redundant!

~J(xv+i, yv+j, zv+k) &&... % pixelposition already set?

sqrt( (xv+i-initPos(1))^2 +...

(yv+j-initPos(2))^2 +...

(zv+k-initPos(3))^2 ) < maxDist &&... % within distance?

cIM(xv+i, yv+j, zv+k) <= (regVal + thresVal) &&...% within range

cIM(xv+i, yv+j, zv+k) >= (regVal - thresVal) % of the threshold?

% current pixel is true, if all properties are fullfilled

J(xv+i, yv+j, zv+k) = true;

% add the current pixel to the computation queue (recursive)

queue(end+1,:) = [xv+i, yv+j, zv+k];

if tfMean

regVal = mean(mean(cIM(J > 0))); % --> slow!

end

end

end

end

end

end

%%%END OF REGION GROWING ALGORITHM

% loop through each slice, fill holes and extract the polygon vertices

P = [];

for cSli = 1:nSli

if ~any(J(:,:,cSli))

continue

end

% use bwboundaries() to extract the enclosing polygon

if tfFillHoles

% fill the holes inside the mask

J(:,:,cSli) = imfill(J(:,:,cSli), 'holes');

B = bwboundaries(J(:,:,cSli), 8, 'noholes');

else

B = bwboundaries(J(:,:,cSli));

end

newVertices = [B{1}(:,2), B{1}(:,1)];

% simplify the polygon via Line Simplification

if tfSimplify

newVertices = dpsimplify(newVertices, simplifyTolerance);

end

% number of new vertices to be added

nNew = size(newVertices, 1);

% append the new vertices to the existing polygon matrix

if isequal(nSli, 1) % 2D

P(end+1:end+nNew, :) = newVertices;

else % 3D

P(end+1:end+nNew, :) = [newVertices, repmat(cSli, nNew, 1)];

end

end

% text output with final number of vertices

disp(['RegionGrowing Ending: Found ' num2str(length(find(J)))...

' pixels within the threshold range (' num2str(size(P, 1))...

' polygon vertices)!'])

% code

end

and Call it as

IR=imread('img6.jpg');IR=IR(:,:,1);

figure, imshow(IR), hold all

[poly im] = regionGrowing(IR,[],15,1200); % click somewhere

im=uint8(im);

imshow(im,[])

Image Analyst
on 22 Jul 2013

Not sure exactly what you're doing but if you have multiple regions, then you have to pick a seed location in each one and grow it by itself. Each region grows independently. That's just how region growing operates. If you can find your regions some other way, like via thresholding or something, then you can use that instead.

For that image you uploaded, there is no reason that I see to employ region growing at all. You can just threshold or some other more standard kind of thing. Or even try the chan-vese segmentation which I think they've finally put into the toolbox (but I haven't had a chance to look at yet).

Image Analyst
on 23 Jul 2013

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yang Tiffany
on 6 Nov 2017

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