How can i measure the distance of each pixel of a binary image from a specified co-ordinate?

I'm trying to measure error in roundness. I have got a point i.e., the center point co-ordinates(Xc,Yc). Now from this point i have to measure the distance of each pixel of the circle geometry so as to get the mean radius. So can anyone help me?

Answer 1

[Image Analyst]

Use sqrt() with the coordinates of the binary image

distances = sqrt((x-Xc).^2 + (y-Yc).^2);

You can also use regionprops(binaryImage, 'EquivDiameter') to get the mean radius

props = regionprops(binaryImage, 'EquivDiameter')
allDiams = [props.EquivDiameter];
averageRadii = allDiams / 2;

[Dina Abd El-twab]

could you help me to measure the largest distance (width) of the white shape in millimeters?

Image Analyst

[darova]

[Image Analyst]

Dina:

props = regionprops(binaryImage, 'BoundingBox')
width = props.BoundingBox(3);

[Dina Abd El-twab]

I want the distance to be in millimeters(mm) not in pixels

Can we contact in this link ? It is a new question

https://in.mathworks.com/matlabcentral/answers/517136-measure-the-maximum-distance-in-millimeters-mm

Image Analyst

[Image Analyst]

Then you need to multiply by the number of millimeters per pixel:

props = regionprops(binaryImage, 'BoundingBox')
width = props.BoundingBox(3) * mmPerPixel;

See attached demo.