How to smoothen a curve so I can separate 2 objects?

Greetings to all.

I wish to smoothen a curve drawn in an image, so I can separate it into 2 objects.

Here is the code used to produce the curve:

    THETA=linspace(0,pi,cirP);

    Radii = abs( drawPoint(1,2) - cenDraw(1,2) );

    [cirCoorX cirCoorY] = pol2cart(THETA,Radii);
    cirCoorY = cirCoorY + cenDraw(1,1);
    cirCoorX = cirCoorX + cenDraw(1,2);

    cirCoor = zeros( cirP, 2 );
    cirCoor(:,1) = cirCoorY;
    cirCoor(:,2) = cirCoorX;

    % round up the decimal to integer
    cirCoor2 = cirCoor;
    for i = 1 : cirP
        yCoor = cirCoor2(i,1);
        xCoor = cirCoor2(i,2);

        yCoorUp = ceil(yCoor);
        xCoorUp = ceil(xCoor);

        if yCoorUp ~= yCoor
            yDiff = yCoorUp - yCoor;
            if yDiff >= 0.5
                yCoor = ceil(yCoor);
            else
                yCoor = floor(yCoor);
            end
        end

        if xCoorUp ~= xCoor
            xDiff = xCoorUp - xCoor;
            if xDiff >= 0.5
                xCoor = ceil(xCoor);
            else
                xCoor = floor(xCoor);
            end
        end 

        cirCoor2(i,1) = yCoor;
        cirCoor2(i,2) = xCoor;        
    end 

   %%Draw the arc   
   bwFil2 = bwFil;
   for i = 1 : cirP
       yBlack = cirCoor2(i,1);
       xBlack = cirCoor2(i,2);       
       bwFil2(yBlack,xBlack) = 0;
       % figure; imshow(bwFil2); title('bwFil2')
   end

Here is the image before the curve is drawn: http://www.imgplace.com/viewimg543/1755/94beforecurve.png

and after the curve is drawn: http://www.imgplace.com/viewimg259/6868/25aftercurve.png

As you can notice, the curve is not smooth and the bwlabel may not be able to recognise 2 separate objects properly.

Any guide is welcomed! Thanks.