How to extract the information from a specific line which draws on an image in matlab?

Dear all, I have a problem for my project. I have a bunch of matrixs M by N by Z.

I binerized all matrixs and find the boundaries for each M by N matrix and apply them on original image same as the attached images (Red lines).

I would like to extract the information from cells which assign to a specific line.

To do this, I draw a shrinked border in black color and I would like to extract the information of the cells that the black line overlab with them.

Here I mean the black line which shows in the third image.

[Max Heimann]

You want the coordinates of the black line you plotted?

[Adam Danz]

...or do you want to get color information of the image within the black circle?

[Ali Hariri]

https://www.mathworks.com/matlabcentral/answers/1631275-how-to-extract-the-information-from-a-specific-line-which-draws-on-an-image-in-matlab#comment_1941840https://www.mathworks.com/matlabcentral/answers/1631275-how-to-extract-the-information-from-a-specific-line-which-draws-on-an-image-in-matlab#comment_1942225

Dear Max Heimann and Adam Danz

I need the color information of the pixels in my original image which has the same location as black line in the processes image.

imagine the (x,y) positions of the black line is my target which I need to know its color information from my original image.

Answer 1

[Image Analyst]

If xBlack and yBlack are the vectors that you plotted for the black curve, you can get the values underneath the lines by doing this

for k = 1 : length(xBlack)
    v(k) = data(yBlack(k), xBlack(k));  % Note that y comes first because it's "row".
end

v will be a vector of data values at the black curve locations.

[Ali Hariri]

Dear Image Analyst thank you for your considration, but it returns this error

Undefined function 'data' for input arguments of type 'double'.

Error in I3_Tempdiff (line 183)

v(k) = data(YT(k), XT(k)); % Note that y comes first because it's "row".

[Image Analyst]

@Ali Hariri you have to replace "data" with the ACTUAL name of your variable. You didn't tell us what it is so I couldn't use it. For example if your data matrix is actually called "mountain" then do

for k = 1 : length(xBlack)
    v(k) = mountain(yBlack(k), xBlack(k));  % Note that y comes first because it's "row".
end

Same thing for xBlack and yBlack of course. Use the actual name of the vectors you used to plot that black ring, not the arbitrary names I chose.

[Image Analyst]

I'm not sure what you mean. I don't see any grating effect. Do you mean ripples? Or noise? Maybe try medfilt2() to do a median filter?

[Image Analyst]

What does this have to do with @Ali Hariri's current discussion in this thread? Ali, do you know this anonymous person? Is he working on your project with you? Does this question belong here? Or as a new question by itself in a different thread?

[Anonymous]

No, it was a seperate question actually, I am sorry if that was an inappropriate way to ask here in this discussion.

[Ali Hariri]

Dear @Image Analyst I found my mistake here, thank you for your support. Furthermore, I dont know Anonymous, as said it was a separate question.