For this experiment, we have used a photo of ornament that has a lot of holes (embedded transparency), curves and shadows. It has taken a hard test of the automated tools. It is harder to remove the background than the previous two object types.
We take an image of a wrist watch with a lot of holes, curves, shadow, delicate edge, etc. It has also a contrasting gradient background. It is quite tough to remove the background from such a photo perfectly without the manual touch up.