apply region growing code to my image
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Hi! I am using this code (see link) although it is a bit old. The example given by the author works:
load example
figure, imshow(cIM, [0 1500]), hold all
poly = regionGrowing(cIM, [], 300); % click somewhere inside the lungs
plot(poly(:,1), poly(:,2), 'LineWidth', 2)
I would like to do the same with my image (example_my.jpg) getting the output on the right.
Is there any parameter I should change?
It always leads me to an error but I can't find a solution.
cIM_1 = im2double(imread('example_my.jpg'));
% grayImage = rgb2gray(cIM_1);
% J = im2uint16(grayImage);
% imshow(J)
figure, imshow(cIM_1, [0 1500]), hold all
poly = regionGrowing(cIM_1, [], 300); % click somewhere inside the lungs
plot(poly(:,1), poly(:,2), 'LineWidth', 2)
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采纳的回答
Image Analyst
2023-1-27
Try this:
% Demo by Image Analyst
clc; % Clear the command window.
close all; % Close all figures (except those of imtool.)
clear; % Erase all existing variables. Or clearvars if you want.
workspace; % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 16;
markerSize = 40;
%--------------------------------------------------------------------------------------------------------
% READ IN TEST IMAGE
folder = [];
baseFileName = 'example_my.jpg';
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
grayImage = imread(fullFileName);
% Get the dimensions of the image.
% numberOfColorChannels should be = 1 for a gray scale image, and 3 for an RGB color image.
[rows, columns, numberOfColorChannels] = size(grayImage)
if numberOfColorChannels > 1
% It's not really gray scale like we expected - it's color.
fprintf('It is not really gray scale like we expected - it is color\n');
% Extract the blue channel.
grayImage = rgb2gray(grayImage);
end
%--------------------------------------------------------------------------------------------------------
% Display the image.
subplot(2, 2, 1);
imshow(grayImage, []);
impixelinfo;
axis('on', 'image');
title('Original Gray Scale Image', 'FontSize', fontSize, 'Interpreter', 'None');
% Update the dimensions of the image.
% numberOfColorChannels should be = 1 for a gray scale image, and 3 for an RGB color image.
[rows, columns, numberOfColorChannels] = size(grayImage)
% Maximize window.
g = gcf;
g.WindowState = 'maximized';
drawnow;
%--------------------------------------------------------------------------------------------------------
% Display histogram
subplot(2, 2, [2, 4]);
histogram(grayImage);
grid on;
title('Histogram of Image', 'FontSize', fontSize, 'Interpreter', 'None');
%--------------------------------------------------------------------------------------------------------
% Threshold to create mask
lowThreshold = 31;
highThreshold = 255;
% Interactively and visually set a threshold on a gray scale image.
% https://www.mathworks.com/matlabcentral/fileexchange/29372-thresholding-an-image?s_tid=srchtitle
% [lowThreshold, highThreshold] = threshold(lowThreshold, highThreshold, grayImage);
mask = grayImage >= lowThreshold & grayImage <= highThreshold;
xline(lowThreshold, 'Color', 'r', 'LineWidth', 2)
% Get rid of blobs touching the border.
% mask = imclearborder(mask);
% Take 2 largest blobs.
mask = bwareafilt(mask, 2);
% Fill the blobs.
% mask = imfill(mask, 'holes');
subplot(2, 2, 3);
imshow(mask);
impixelinfo;
axis('on', 'image');
title('Mask Image', 'FontSize', fontSize, 'Interpreter', 'None');
%--------------------------------------------------------------------------------------------------------
% Get the areas, diameters, and centroids.
props = regionprops(mask, 'Area', 'Centroid', 'EquivDiameter')
if isempty(props)
warningMessage = 'No blobs found!'
uiwait(warndlg(warningMessage));
return;
end
allAreas = [props.Area]
allDiameters = [props.EquivDiameter]
xy = vertcat(props.Centroid)
% Plot centroids on image as red crosshairs
xCentroids = xy(:, 1);
yCentroids = xy(:, 2);
hold on;
plot(xCentroids, yCentroids, 'r+', 'LineWidth', 3, 'MarkerSize', 20)
10 个评论
Image Analyst
2023-1-30
You have to use the thresholds to create the mask first. Of course bwselect won't work until mask is created. So like:
%--------------------------------------------------------------------------------------------------------
% Threshold to create mask
lowThreshold = 31;
highThreshold = 255;
% Interactively and visually set a threshold on a gray scale image.
% https://www.mathworks.com/matlabcentral/fileexchange/29372-thresholding-an-image?s_tid=srchtitle
% [lowThreshold, highThreshold] = threshold(lowThreshold, highThreshold, grayImage);
mask = grayImage >= lowThreshold & grayImage <= highThreshold;
xline(lowThreshold, 'Color', 'r', 'LineWidth', 2)
% Get rid of blobs touching the border.
% mask = imclearborder(mask);
% Take 2 largest blobs.
mask = bwareafilt(mask, 2);
% Ask user to click on the blob they want to keep.
uiwait(helpdlg('Click on the blob you want to keep'));
% Extract only the blob they clicked on.
mask = bwselect(mask, 8);
% Display the mask.
subplot(2, 2, 3);
imshow(mask);
impixelinfo;
axis('on', 'image');
title('Mask Image', 'FontSize', fontSize, 'Interpreter', 'None');
更多回答(1 个)
Benjamin
2023-1-29
编辑:Image Analyst
2023-1-29
Region growing is a way to divide an image into smaller parts based on where different colors or shapes are found. It's like selecting starting points to divide the image into.
0 个评论
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