How to calculate the area of single leaf along with its height

How to calculae the area of single leaf with its height? Since the leaf is rounded and not flat, how to estimate the area of other sides of the leaf?

[Diwakar Diwakar]

It's challanging task. still you can make an approximation by assuming the leaf's shape resembles a hemisphere or a portion of a sphere.

Example code:

% Leaf height (in centimeters)
height = 10;

% Radius of the rounded leaf (assuming a hemisphere or a portion of a sphere)
radius = height / 2;

% Calculate the approximate area of the rounded leaf
area = 2 * pi * radius^2;

disp(['The estimated area of the leaf is: ', num2str(area), ' cm^2']);

 

[Malini]

Thank you Diwakar.

Answer 1

[Image Analyst]

First of all you need to segment the plant, which is easy enough. Then get the skeleton of the leaf with bwskel. Then you need to get the radius at each location along the leaf's skeleton with a distance transform bwdist . Then square it and multiply by pi and sum it up for all points along the skeleton.

A demo for a similar (but not identical) is attached.

[Malini]

Thank you @Image Analyst. Will work on it

[Image Analyst]

You're welcome, but I'm not sure why you Accepted the other, obviously incorrect answer. Looks like a typically wrong result a chatbot might give. You'll soon realize it is no good.

[Malini]

Hi @Image Analyst Nothing intentional. He answered me yesterday. I did try and didnt suit my problem.

As you might have observed that I have accepted the answer after your reply, means that I accepted your answer only. Really no idea how it has ended up there.

Also I didnt find seperate button near your answer or I may need more familiarity with this platform.

[Image Analyst]

@Malini See my boilerplate instructions below:

If this Answer solves your original question, then could you please click the "Accept this answer" link to award the answerer with "reputation points" for their efforts in helping you? They'd appreciate it. Thanks in advance. 🙂 Note: you can only accept one answer (so pick the best one) but you can click the "Vote" icon for as many Answers as you want. Voting for an answer will also award reputation points. If you decide to change the "Accepted" answer, you'll have to unaccept that one first and then accept the one you really wanted to accept. Unaccepting an answer does not remove the reputation points awarded to that person even though it does not show up in green as the Accepted answer anymore.

[Malini]

@Image Analyst Hi Image Analyst, I have appended the following code and I wanted to kindly ask for your feedback on whether I've implemented these steps correctly.

Thank you once again for your time and assistance.

radii = diameterImage(diameterImage > 0) / 2;

% Square the radii

squaredRadii = radii.^2;

% Estimate leaf area by summing up the squared radii and multiplying by pi

leafArea = sum(squaredRadii) * pi;

message1 = sprintf('Leaf Area = %.1f Pixels', leafArea);

msgbox(message1);

[Malini]

Also my dataset is like this. How to induvidually calculate the leaf area

[Image Analyst]

To get the area of each leaf, you need to make sure they're separated and then threshold to get a mask (binary image). Then you simply do

props = regionprops(mask, 'Area');
allAreas = [props.Area]

Answer 2

[Vishnu]

Hi @Malini,

I understand that you want to get an approximation for the area of a rounded leaf, now since the leaf is rounded the only way to get the approx area is to divide the entire height of the leaf into multiple smaller unit which can be cyllindrical(This is assumption for the approximation). We can then procced to integrate this cyllindrical shell element across the height of the entire leaf with an integral function to get the area of the leaf.

Here is the working code for this approach:

function leafArea = estimateLeafArea(radius, height)
    % Define the function representing the leaf shell
    leafShell = @(x) sqrt(radius^2 - (radius/height)^2 * x.^2);
    % Define the integration limits
    lowerLimit = -height/2;
    upperLimit = height/2;
    % Perform the integration using the integral function
    leafArea = integral(leafShell, lowerLimit, upperLimit);
end