How do i copy or erase a labeled object in an image?

Hi there. I am working on a project that involves multiple objects in an image. I need to know how can I use each object separately to work with it. One way that i thought might work is to copy each labeled object into a new image (empty one). Can anyone tell me how to do this? Or another possible way would be to simply erase all other labeled objects, so that i only have the first one. Can someone please tell me how can I do this? Both methods are OK.

Answer 1

[Image Analyst]

You can use ismember() to extract the labeled objects that you want. If you want, say, blob #42, you can do this to get a labeled image with just blob 42

labeledImage2 = ismember(labeledImage, 42);  % A labeled image.

If you want a binary image, just compare to 0:

labeledImage2 = ismember(labeledImage, 42) > 0;  % A binary image.

You can also pass in an array:

labeledImage2 = ismember(labeledImage, [10, 13, 42]);  % A labeled image.

There is also a function called bwselect() that you may be interested in. This lets you specify coordinates and will extract the blobs that contain those coordinates.