Any suggestions to measure the distance between two lines or regions (the dip represents low intensity)

Here I plotted the centre of gravity between two regions, then I would like to measure the distance between these two line using gridline or region of interest, maybe , any suggestions?

Answer 1

[Varun]

Hello!

As per my understanding, you want to measure the distance between two lines that have been plotted in the figure. There are multiple ways to go about it:

1. Using the “drawline” function: The “drawline” function lets you create a customizable region-of-interest. So, in the figure window, you can measure the distance between the lines by connecting the lines using “drawline”, by placing one end-point on each line. The line’s “Position” properties can be used to get the coordinates of its endpoints, using which the Euclidean distance can be calculated. Example:

h1 = drawline(); 
distance=sqrt((h1.Position(1,1)-h1.Position(2,1))^2 + (h1.Position(1,2)-h1.Position(2,2))^2); 

You may refer to the following documentation to learn more about “drawline”: https://www.mathworks.com/help/images/ref/drawline.html

2. Using the “ginput” function: The “ginput” function lets you identify axes coordinates in a Figure window. So, “ginput” can be used to pick two points, one lying on each line. Using the coordinates of these points, the Euclidean distance can be calculated. Example:

disp('Select a point on Line 1:'); 
[x1_point, y1_point] = ginput(1); 
scatter(x1_point, y1_point) 

% Select points on Line 2 
disp('Select a point on Line 2:'); 
[x2_point, y2_point] = ginput(1); 
scatter(x2_point, y2_point); 

% Calculate the distance between the selected points 
distance = sqrt((x2_point - x1_point^2 + (y2_point- y1_point)^2); 

You may refer to the following documentation to learn more about “ginput”: https://www.mathworks.com/help/matlab/ref/ginput.html

Hope this helps!

Thanks,

Varun