If you want to have dynamic images on your website, the web server where you host it needs to have the proper software for this. As opposed to using static images with a fixed size, you may have thumbnails and automatically resized images depending on the device a visitor uses or you can even flip and invert images through a script app. All of these things are doable via ImageMagick and GD library - 2 pieces of software which may be installed on a server and which work with a great number of widespread scripting languages including: Perl, Python and PHP. In this way, you could use images with any web-based app that you'd like, regardless what language it was created with - a custom-made Perl script or a PHP one. The 2 libraries will enable you to work with more than one hundred different image formats including GIF, PNG, TIFF, JPEG, etcetera.