OpenCV#4: Remove small blobs from binary image

// Function to remove small blobs from the binary image
IplImage* remove_small_objects( IplImage* img_in, int size )
{
    IplImage* img_out       = cvCloneImage( img_in );  // return image
    CvMemStorage* storage   = cvCreateMemStorage( 0 );    // container of retrieved contours
    CvSeq* contours         = NULL;
    CvScalar black          = CV_RGB( 0, 0, 0 ); // black color
    CvScalar white          = CV_RGB( 255, 255, 255 );   // white color
    double area;

    // find contours in binary image
    cvFindContours( img_in, storage, &contours, sizeof( CvContour ), CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE );  

    while( contours )   // loop over all the contours
    {
        area = cvContourArea( contours, CV_WHOLE_SEQ );
        if( fabs( area ) <= size )  // if the area of the contour is less than threshold remove it
        {
            // draws the contours into a new image
            cvDrawContours( img_out, contours, black, black, -1, CV_FILLED, 8 ); // removes white dots
        }
/*        else
        {
            cvDrawContours( img_out, contours, white, white, -1, CV_FILLED, 8 ); // fills in holes
        }*/
        contours = contours->h_next;    // jump to the next contour
    }

    cvReleaseMemStorage( &storage );
    return img_out;
}