Particle size measurement from SEM image

How can I measure particle diameter with respect to the scale in the SEM image.

Answer 1

[Stephan]

You can use the imfindcircles function (example here) which gives back the radii of detetcted circles in combination with houghlines (example here) to get the needed information from the image. This should work properly since your image has low noise and a good contrast.

[Qaisar Latif]

Hi, Stephan. Thanks for the help. The imfindcircles function works well for a circular object. As you can see my particles or slightly elongated along the horizontal axis, the imfindcircles function might give a wrong (area/dia/radii) estimate. Is it possible to draw a boundary around the particle using some other matlab function and then find the exact (area/dia/radii)?

[Stephan]

You may be interested in:

https://de.mathworks.com/help/images/ref/bwperim.html

https://de.mathworks.com/help/images/ref/bwarea.html

https://de.mathworks.com/help/images/pixel-values-and-image-statistics.html

https://de.mathworks.com/help/images/morphological-filtering.html

Im sure you will find a function tha satisfies your needs.