batch for transforming images

[Donn]

I just discovered something today.
1. It uses imagemagick.
2. I dunno about the dpi, but check the man pages for that.
3. Here's the recipe:
ls *.jpg | sed 's/.jpg//' | xargs -I F convert F -quality 80 F.png
That:
a. picked all jpg files.
b. stripped the .jpg off (using sed)
c. used 'xargs' to handle things like too many files at once and spaces in 
names. It also puts the filename into 'F'
(The arg to xargs is a dash capital "i", BTW, not a lower L)
d. calls convert on file 'F' setting quality to 80 and converting to F.png

You can adjust as you need to.

HTH
\d