I use this script to resize digital images for web pages and it works pretty well.
You can change the file format to whatever you want, ie tiff's.
#!/bin/sh
# script to rename and resize jpg files
#it also takes the old files and moves them to a dir called Raw
#The line where it says: R$outfilename the R can substituted
#whatever name you want to prepend to it
mkdir Raw
egrep "SizeY|Magnification" *.jpg >> magDB
for filename in *; do
case $filename in
*.jpg )
infilename=$filename
outfilename=${filename%.jpg}.jpg
convert -geometry 345x184 $infilename R$outfilename
mv $infilename Raw;;
* )
echo "error: $filename not a JPG file." ;;
esac
done
# an ! at the end of the 645x484 will force the aspect ratio to change. i dont
#need that. just in case, tho. :-)
Dan Williamson