If you want to resize your photos to put them on your blog or website. As you know, you can’t upload your photos on a webpage with the highest resolution because a web gallery became inaccessible and too slow to load. Then maybe you have a folder containing every photo of your holidays and you want to resize it at 768 of width maintaining the original aspect ratio. To make a resize there are many tools but here I suggest a command-line tool called “mogrify”. This tool will be installed with ImageMagick Libraries, so all you have to do is installing ImageMagick.
Here I am assuming that your operating system is Ubuntu Hardy:
sudo apt-get install imagemagick
After ImageMagick installed, you can use mogrify.
For example, you have a folder called “travels” located in “/home/yourname/Pictures/“. Go to that directory, make a thumbs folder and copy original images into “thumbs”. After that you can start the image resizing process:
cp /home/user/yourname/Pictures/travels/* /home/yourname/Pictures/travels/thumbs/
mogrify -resize 640 *.jpg
Now you will see in “/home/yourname/Pictures/travels/thumbs/” every your image file resized to 768 of width. If you want to force resizing to a particular size without maintaining the original aspect ratio you could change mogrify options:
mogrify -resize 768×576! *.jpg