Imagemagick Crop and Resize
#!/bin/sh
DIRECTORY="thumbnails"
if [ ! -d "$DIRECTORY" ]; then
mkdir "$DIRECTORY"
fi
for i in *.jpg; do
convert $i -resize 300x225^ -gravity center -crop 300x225+0+0 thumbnails/$(basename $i);
done
echo "Done! Images save to '$DIRECTORY' directory"