Thanks I'll have a look. Really though I'd prefer a PC solution as potentially I have 1000s of subtly different images to convert and I don't own 060/PPC Amigas for all the processing and UAE is not exactly simple to drag and drop files between the real world.
I think a lot of people don't understand how to use WinUAE properly. It *is* easy to drag and drop between Windows/AmigaOS when you have UAE setup correctly. You just make a common folder shared by both OS's, then create a shortcut on your Windows desktop to that folder. Anything you drop into that folder from either the Windows or AmigaOS side will be available to both OSes.
You do this by going into the hard drive settings of UAE, and creating a virtual hard drive for the Amiga that is actually a folder on your Windows hard drive. This is NOT a hard file, nor an Amiga formatted partition on your Windows hard drive, nor a specific hard drive formatted as an Amiga. The new versions of UAE actually let you specify that a standard Windows folder/directory on your PC be treated as a "real" hard drive by the emulated Amiga. You can even boot AmigaOS from it, and it's fast. From the Windows side you can access all the Amiga files instantly, add files, remove files, edit files, etc. Just as if it were a Windows folder (because it is).
I use ImageFX a lot under UAE. I have created a Windows folder just to be a shared folder with Amiga OS. Whenever I need to work on graphics files between the two OSes, I put them in this folder, then I batch process them with ImageFX on the Amiga side, switch over instantly to the Windows side (middle mouse button or ALT-TAB) while AmigaOS is still running in the background and load them into PhotoShop, Irfanview, whatever.....if I need to do more processing on the Amiga side I just instantly switch back to AmigaOS and load them into the Amiga application. It's as fast to switch back and forth between OSes as switching screens on the Amiga. It's fantastic.
So, if I were you I'd create such a shared folder, drag all your PC graphics files into it from the Windows side, then flip over to the AmigaOS side and batch process them to HAM format with ImageFX's AutoFX Batch processor (specify output to the shared folder). Under UAE ImageFX flies and it should only take seconds to process each image. Then when the batch processing is done flip back over to the Windows side (ALT-TAB) and there you will have the processed files available to Windows.