Improving object separation with live depth data

Hey, I'm building a portrait mode into my camera app but I'm having trouble with matching the quality of Apples native camera implementation. I'm streaming the depth data and applying a CIMaskedVariableBlur to the video stream which works quite well but the definition of the object in focus looks quite bad in some scenarios. See comparison below with Apples UI + depth data.

What I don't quite understand is how Apple is able to do such a good cutout around my hand assuming it has similar depth data to what I am receiving. You can see in the depth image that my hand is essentially the same colour as parts of background, and this shows in the blur preview - but Apple gets around this.

Does anyone have any ideas?

Thanks!

Improving object separation with live depth data
 
 
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