Post editing on jewellery photos

We have a series of images of jewellery shots that need to be edited.

There are two types:

1. Images taken on a whiteish background that need to the background to be retouched so that it is the 'brilliant white' we require.
2. Images taken on a marble tile - there are 100s of these but the key is consistency so the marble is a similar, if not the same colour, in all images.

We are happy to send sample of images of the 'look' we need so that you can better assess how long the work will take.