How to find the internal and external radius of a ring using matlab image processing toolbox

For example get this image

[KSSV]

Attach the image....!

Answer 1

[Akira Agata]

By measuring the 'equivalent diameter' for each region, you can obtain the inner and outer radius. Here is an example.

% Read your image and binarize it
I = imread('Oil_Seal_Top_370003A__34285.1413827494.1280.1280.jpg');
Igray = rgb2gray(I);
BW = imbinarize(Igray);

% Measure the outer radius
BWout = ~BW;
BWout = imfill(BWout,'holes');

statOuter = regionprops(BWout,{'EquivDiameter','Centroid'});
outerRadius = statOuter.EquivDiameter/2;

% Measure the inner radius
BWin = imclearborder(BW);
BWin = imopen(BWin, strel('disk',5)); % Remove noise

statInner = regionprops(BWin,{'EquivDiameter','Centroid'})
innerRadius = statInner.EquivDiameter/2;

% Show the result
figure
imshow(I)
hold on
viscircles(statOuter.Centroid, outerRadius,'Color','r')
viscircles(statInner.Centroid, innerRadius,'Color','r')

The result is:

>> innerRadius
innerRadius =
278.8980
>> outerRadius
outerRadius =
374.5866

[Rangika Mark]

Thank you Mr.Akira Agata for mind me the solutions this is simple,early I used imfindcircle function in that I have to input the pixel value