How to find the width of this object at its center?

As you can see my object is a bit irregular in shape with bigger width at top and bottom, i would like to find out the width of the object at its center (or better smallest width in the central location).

I have used regionprops and bounding box, but it only output the max width.

Thanks in advanced..

Answer 1

[Prabhan Purwar]

Hi,

Following code may help

Change the threshold value and Morphological parameters according to your need.

clc
close all
clear 
img = imread('image.jpeg');
grayImage = rgb2gray(img);
figure
imshow(grayImage);
[pixelCount, grayLevels] = imhist(grayImage);
figure
bar(pixelCount);
% threshold (binarize) the image.
binaryImage = grayImage > 20;
% Get rid of small blobs:
binaryImage = bwareaopen(binaryImage, 500);
% Morphologically close image
binaryImage = imclose(binaryImage, ones(15));
figure
imshow(binaryImage);
hold on
[boundaries, L, N, A] = bwboundaries(binaryImage);
numberOfBoundaries = size(boundaries, 1);
% Find out which are interior boundaries
enclosed_boundaries = find(A(:,1));
for k = 1 : numberOfBoundaries
  thisBoundary = boundaries{k};
  if ismember(enclosed_boundaries, k)
    % It's not an enclosed boundary - it's an outer one.  Plot in red.
    plot(thisBoundary(:,2), thisBoundary(:,1), 'r', 'LineWidth', 3);
  else
    % It's an enclosed boundary.  Plot in green.
    plot(thisBoundary(:,2), thisBoundary(:,1), 'g', 'LineWidth', 3);
  end
end
hold off

Kindly have a look at the following links for further references:

• https://www.mathworks.com/help/images/ref/bwboundaries.html (openExample('images/DisplayObjectBoundariesInRedAndHoleBoundariesInGreenExample'))
• https://www.mathworks.com/help/images/ref/imclose.html