Hi, I am using OpenCV for blob detection,
This is code from the OpenCV website
and I change background to black to give more contrast white/black.


In front of the webcam, I gonna have a picture that has a black color shape and white background.

Is there way to trace the outline of the  black color shape?

Thanks.

-------------Code---------------

import hypermedia.video.*;

OpenCV opencv;

void setup() {

   size( 640, 480 );

   // open video stream
   opencv = new OpenCV( this );
   opencv.capture( 640, 480 );

}

void draw() {

   background(0);

   opencv.read();           // grab frame from camera
   opencv.threshold(80);    // set black & white threshold

   // find blobs
   Blob[] blobs = opencv.blobs( 10, width*height/2, 100, true, OpenCV.MAX_VERTICES*4 );

   // draw blob results
   for( int i=0; i<blobs.length; i++ ) {
       beginShape();
       for( int j=0; j<blobs[i].points.length; j++ ) {
           vertex( blobs[i].points[j].x, blobs[i].points[j].y );
       }
       endShape(CLOSE);
   }

}