If you have to resize an image, you can use your favourite image viewer or editor program. It’s really simple, but if you need to resize a huge number of photos you have to do a really tedious work. As you should know the best jobs for a computer are the tedious and repetitive ones.
So let’s start this how to.
First of all we are going to use the imagemagik software suite, so please download the imagemagick for your PC from the following link:
then install it.
Now imagine you have the images you want to resize into the directory /path/to/images, open a terminal and issue the following command:
$ cd /path/to/images/
now issue the following command to resize to 25% your images. (be careful, the following command will change your files so make sure to work on a copy of the images):
$ mogrify -resize 25% *
Now your files has been changed (and you lost the original ones, so make sure to work on a copy of the images)