I have a Canon IXUS 800 IS digital camera that is happy to write images to an RS-MMC (+ adaptor). High quality images are 2816x2112.

What I would like is an app that can shrink these images to a size suitable for e-mail "postcard" attachments that I could send using my Nokia 770 + Nokia 6600.

On Linux I could use something like:

djpeg big.jpg | pnmscalefixed -xsize=1024 -ysize=768 | cjpeg > small.jpg

I suppose I could try to port theses comand line utilities and use them with xterm.

Anyone tried anything similar? Have any better suggstions?