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(Not recommended) Create mask within image

createMask is not recommended. Use the createMask object function associated with the new ROI objects instead, described in Compatibility Considerations.



BW = createMask(h) returns a mask, or binary image, with 1s inside the ROI object h and 0s everywhere else. The input image must be contained within the same axes as the ROI object.

BW = createMask(h,himage) returns a mask the same size as the image himage, with 1s inside the ROI object h and 0s everywhere else. This syntax is required when the axes that contains the ROI holds more than one image.


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Create an ellipse ROI.

e = imellipse;

Use the mouse to reshape and reposition the ellipse. Then, create a binary mask from the ROI. Pixels inside the ROI have the value 1, and pixels outside the ROI have the value 0. Display the mask in a new figure.

BW = createMask(e);

Input Arguments

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ROI object, specified as an imellipse, imline, impoint, impoly, or imrect object.

Handle to one image, specified as a handle.

Output Arguments

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Mask, returned as a binary matrix. The mask is the same size as the input image contained in the same axes as h, or the image himage.

Version History

Introduced in R2008a

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Not recommended starting in R2018b