Moving from Tiger to MountainLion > Pasted graphics are lost

Hi everybody, I’ve created a lot of documents with pasted graphics (.pict) on Tiger on a PPC Mac. I recently imported those databases into the latest version of DEVONThink on Mountain Lion but now, my pasted images are gone.

I can still paste images but they are now in a new (.tiff) format. I believe Apple dropped support for .pict.

Is there a converter so that I can view all my older documents including their images?

Thanks,
Martin