how to remove blobs with SimpleBlobDetector

edit

Hello,

Im trying to use SimpleBlobDetector to remove small object from my binary image,

first I creat an object of type SimpleBlobDetector, and then detect blobs like this code below

    SimpleBlobDetector blobDetector( params );
    blobDetector.create("SimpleBlob");      
    blobDetector.detect( src, keyPoints );

This code detect for example 2 blobs from 3 according to the parameters. Now my question is how to delete the unwanted blob from the mage...?

I have two other questions, how to get the coordinates of blobs, and can we frame a blob in a rectangle?

thanks :)