I agree but I thought, obviously wrongly, that Mike wanted the images in a format that he could edit and save without loosing quality. My thought was that whereas a jpeg is compressed and therefore looses quality everytime it is saved a png image doesn't so that would be his answer!
I'm Mike
John asked the question :)
Either way there is no gain in changing the file type the files are already hosed.
If you are going to edit a file then you should never use Jpeg,
it's a simple fact of life, even at the top quality setting you will loose data every time you save the file and in a lot of circumstances just rotating the image will also cause data loss
The only use for JPEG images is for the last stage in producing files for web use and that is no longer really needed as the replacement for JPEG to solve these issues is already available, PNG was developed for this very reason, plus it supports alpha channels which allows better Matting
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