imfreehand .createMask for single drawn line instead of region

Hi, Im wondering if theres a way to modify the demo you've posted around using imfreehand() to use the createMask function to apply to only a single free hand drawn line rather than the entire closed region that line could form. I have been able to successfully make the line using:

hFH = imfreehand();

setClosed(hFH,0);

Then:

% Create a binary image ("mask") from the ROI object.

binaryImage = hFH.createMask();

% Display the freehand mask.

subplot(2, 2, 2);

imshow(binaryImage);

This produces a closed shape from my drawn free hand line in Binary, however I want to create a mask for just the line I drew, not the resulting closed shape. Anyway to do this?

Answer 1

[Image Analyst]

Evidently you haven't see one of my demos, which does what you request. See attached demo in blue text below this snippet.

hFH = imfreehand();
% Get the xy coordinates of where they drew.
xy = hFH.getPosition
% get rid of imfreehand remnant.
delete(hFH);
% Overlay what they drew onto the image.
hold on; % Keep image, and direction of y axis.
xCoordinates = xy(:, 1);
yCoordinates = xy(:, 2);
plot(xCoordinates, yCoordinates, 'ro', 'LineWidth', 2, 'MarkerSize', 10);

[A]

Sorry I missed that demo and thanks for the quick reply. I'm a bit confused about how I could use this to create a Binary Mask of the line drawn. I recently starting learning MatLab but my understanding of .createMask is that it requires the imfreehand object to be passed to it (i.e. binary image = h.createMask() where h= imfreehand()) With this script the freehand object is deleted after its position is taken as x and y coordinates so how would you use that information to generate the binary mask?

[Image Analyst]

This gives you coordinates of the line you drew. If you want a binary mask from that, just create one:

binaryImage = false(rows, columns);
for k = 1 : length(x)
  binaryImage(int32(y(k)), int32(x(k))) = true;
end