It is very often that one has a need to rotate a bunch of images by 90 or 180 degrees clockwise or otherwise, or resize the same bunch of images to a certain size. Read more to learn how you can do it.
First of all, you should defenetely install ImageMagick. If you are using any of the modern Linux distributions (like Red Hat Linux 6/7/8/9), most probably you either have it already installed, or it is available on the distribution CD-ROM. If it is not, then you can always download it from http://www.imagemagick.org/.
Now for the fun part:
[leonid@home tmp]$ cd /home/leonid/files/images
[leonid@home images]$ for IMAGE in *.jpg ; do echo Working with $IMAGE ; mv
"$IMAGE" "$IMAGE.huge" ; convert -resize 800x600 "$IMAGE.huge" "$IMAGE" ; done
[leonid@home images]$ rm -f *.huge
Almost the same thing is for rotating. This time, let’s see how it will look in the script file:
# go into directory with images
# Repeat steps for each JPEG image in the directory
for IMAGE in *.jpg
# Do some noise so that we know that it's working
echo Working with $IMAGE
# Move original image to another file
mv "$IMAGE" "$IMAGE.huge"
# Rotate the backup file and save as original file
convert -rotate 90 "$IMAGE.huge" "$IMAGE"
# Remove backup copies
rm -f *.huge
That’s all folks. ImageMagick has a number of other utilities which can do a number of other things. Check them out.