MATLAB: Finding Center of Arc and Forming Circle from an Image

digital image processingimageimage analysisimage processingimage segmentation

hi, I have a zoomed in image the Moon and from it I need to estimate the Moon Center and form its full outline.

The original image is this one:

Using various commands such as bwareaopen, imcomplement, I have managed to isolate its outline and laid it out on an all black canvass:

Then from here I want to find the center of the circle (moon) and extrapolate its outline: e.g draw a circle of the full moon in the image.

I have tried the imfindcircles command but it seems having a hard time to detect the outline.

Any help with this will be greatly appreciated!

Thank you!

Best Answer

https://blogs.mathworks.com/pick/2008/03/14/fitting-a-circle-easily/

This give a good walk though on fitting a circle using circfit. It might be worth trying this. Once you have the circle you can calculate the centre.

Related Solutions

MATLAB: Finding a circle in an image without using Imfindcircles function

http://www.mathworks.com/matlabcentral/fileexchange/9168-detect-circles-with-various-radii-in-grayscale-image-via-hough-transform

MATLAB: Putting two circles on the same image

Try the following

function [outimg] = CircleIm(radius)
SizeX = 256;
SizeY = 256;
[C, R] = meshgrid(1:SizeX, 1:SizeY);
centerX = 64;
centerY = 64;
centerX1 = 192;
centerY1 = 192;
circle = (R - centerY).^2 + (C - centerX).^2 <= radius.^2;
circle1 = (R - centerY1).^2 + (C - centerX1).^2 <= radius.^2;
circles = circle|circle1;
outimg=image(circle|circle1);
colormap([0 0 0.4; 1 1 1]);
end

your method of hold on will make draw the new image on top of the last image. You need to or both images together to retain both circles. The following are drawn with a radius of 20.

Best Answer

Related Solutions

MATLAB: Finding a circle in an image without using Imfindcircles function

MATLAB: Putting two circles on the same image

Related Question