How to do local region-based active contour image segmentation?

Please explain with example code.

Answer 1

[Hari]

Hi Jasmine,

I understand that you want to perform local region-based active contour image segmentation using MATLAB.

In order to perform local region-based active contour image segmentation, you can follow the below steps:

Load and Preprocess the Image:

Read the image and convert it to grayscale if necessary, as active contour methods often work on single-channel images.

I = imread('example.jpg');
if size(I, 3) == 3
    I = rgb2gray(I);
end

Initialize the Contour:

Define an initial contour manually or using a function, such as a circle or rectangle, to start the segmentation process.

mask = zeros(size(I));
mask(50:150, 50:150) = 1; % Example: a square region

Apply Active Contour Segmentation:

Use the "activecontour" function with the 'Chan-Vese' method for local region-based segmentation.

maxIterations = 300;
bw = activecontour(I, mask, maxIterations, 'Chan-Vese');

Display the Results:

Visualize the segmented region by overlaying the contour on the original image.

figure;
imshow(I);
hold on;
visboundaries(bw, 'Color', 'r');
title('Segmented Image with Active Contour');

Refine and Evaluate:

Adjust parameters like the number of iterations and initial mask to improve segmentation results, and evaluate the segmentation visually or with metrics if needed.

Refer to the documentation of "activecontour" function to know more about the properties supported: https://www.mathworks.com/help/images/ref/activecontour.html

Hope this helps!