Calculate each object maximum height and weight

How can I calculate each object maximum height and weight in the following example?

I used this code:

clc;
clear;

I = rgb2gray(imread('http://i67.tinypic.com/14jxq0y.jpg'));

adpt1 = imbinarize(I);
adpt1 = imfill(adpt1, 'holes'); 

[B,L] = bwboundaries(adpt1,'noholes');
stat = regionprops(adpt1,'All');

imshow(adpt1);
hold on
for k = 1 : length(B)
    b = B{k};
    c = stat(k).Centroid;
    plot(b(:,2),b(:,1),'g','linewidth',3);
    text(c(1),c(2),num2str(k),'backgroundcolor','g');
end

[Walter Roberson]

You have curved objects.

For "height" are you looking for the height of the highest point minus the height of the lowest point?

Are you looking to do the equivalent of running a ruler horizontally along the figure and examine the maximum point minus the minimum point at each column, and find the largest difference amongst those -- the "thickest" vertical?

In your object #4, top center, the left side is concave, so if you did that you would have a gap along the vertical line: is only the solid part to be counted, or the furthest reaches?

Are you looking to find the maximum axes and the axes 90 degrees to that? For example in object #6, right center, the maximum axis is along the diagonal from top left to bottom right: is that one of the distances to be measured, and then the other would be the diagonal from bottom left to top right?

Answer 1

[Image Analyst]

Ask regionprops to return the Bounding Box.

In the loop

thisBB = stats(k).BoundingBox
thisWidth = thisBB(3);
thisHeight = thisBB(4);
hold on;
rectangle('Position', thisBB, 'EdgeColor', 'c');

[Ely Raz]

How can I access the Bounding Box information for every object in the loop and print it out (Output line: "object k, width is VALUE, height is VALUE")? (The Bounding Box struct contain 4 numbers which I do not know what they mean and how to extract them out)

Code:

clc;
clear;
I = rgb2gray(imread('http://i67.tinypic.com/14jxq0y.jpg'));
adpt1 = imbinarize(I);
adpt1 = imfill(adpt1, 'holes');  
[B,L] = bwboundaries(adpt1,'noholes');
stat = regionprops(adpt1,'All');
imshow(I);
hold on

for k = 1 : length(B)
    b = B{k};
    c = stat(k).Centroid;
    plot(b(:,2),b(:,1),'g','linewidth',3);
    text(c(1),c(2),num2str(k),'backgroundcolor','g');
    rectangle('Position', stat(k).BoundingBox,'EdgeColor', 'c');
end

[Guillaume]

"The Bounding Box struct contain 4 numbers which I do not know what they mean"

That's easily solved by looking it up in the documentation.

The four values are: [x_upperleftcorner, y_upperleftcorner, width, height]

Now what the regionprops documentation does not explain or link to is what x and y mean in a coordinate system that uses rows and columns!

[Ely Raz]

How can I extract the width, height to 2 different variables from the stat(k).BoundingBox?

[Image Analyst]

I already showed you that:

thisWidth = thisBB(3);
thisHeight = thisBB(4);

[Walter Roberson]

Hee. I see you've started using my naming practice of " this such and such" ;-)

[Image Analyst]

I think I picked that up in 2003 when I learned Java. I thought it was a good idea so I use it occasionally.