MATLAB: For a binay image, how to plot a circle by using the centroid of the white pixel region for any given radius.

Question

Answer 1

Hi!

It appears to me that you want to calculate the centroid of the white spot in your image, and using this centroid value as the center, plot a circle of any radius.

The first part of the question, i.e. finding the centroid of the circle can be evaluate as follows –

im = imread('figure.jpeg'); % Your figure
imBin = imbinarize(im);
imBin = imfill(imBin, 'holes');
BW = regionprops(logical(imBin), 'centroid');
imshow(imBin); 
hold on; 
plot(BW.Centroid(1),BW.Centroid(2),'bx')

The value of the centroid of this image is stored in the variable ‘BW’.

The output is -

(I snipped this output to enhance readability)

Coming to the second part of your question, please refer to this link here to get the relevant steps to plotting a circle with a given center and radius.