Convert Contour into BLOB OpenCV
After a lot of programming, I realized the procedure is:

After a contour is extracted, create a black image with same size as the original image.
Draw the contour in black image. 
Find the coordinate of the contour center by contour feature : moments, x0 and y0.
Use Floodfill() to white-fill the interior of the contour using (x0,y0) as seed point.

The resulting image contains the white BLOB to the corresponding contour.
Hi everyone,
              I am trying to convert a contour to a blob in an image .There are several blobs in image ; the proper one is extracted by applying contour feature. The blob is required to mask a grayscale image.
I have tried extracting each non-zero pixels and pointPolygontest() in order to find the BLOB points, but it requires >70ms to complete the proccess. The application is in 30 fps videos, so I need to convert them within 30ms. I am using OpenCV in python.  Is there a way to convert a contour into a Blob within 30ms in opencv?
Thanks in advance.