I want to find the contours of (parts) image and sent the output to a laser cutter. For example, take this image:

I use this code:

maskv1 = AlphaChannel[RemoveBackground[bal1]];
 contours =  
 ImageMeasurements[   EdgeDetect[Blur[ImageMultiply[bal1, maskv1], 2],
 1], "Contours"]; bal4 = ImageGraphics[   ColorNegate[   
 DeleteSmallComponents[
     Dilation[
      EdgeDetect[BilateralFilter[Graphics[contours], 7, .1]], .6], 
     Method -> "Mean"]], ImageSize -> 600];

The output is:

The red line is done by myself. As you can see, the contour is not closed. The desired output is something like:

So I need a function to close the outline/contour. Who has a suggestion to do this?