ImageMagick and GD are 2 of the most widely used graphic software libraries on the market. They make the dynamic creation and editing of images and graphs on an internet site doable, so they need to be installed on a server if you host your websites on it and you would want to have something different than static images with fixed dimensions. If ImageMagick and GD are set up, you will be able to edit any image in many different ways - generate thumbnails, change the colors, flip it, blur it, and so on. However, these adjustments are doable if the script application that you use on your site enables you to perform such things. The two libraries can easily be used with a lot of web development languages - PHP, Python, Perl, and so forth., and support more than 100 widely used image formats which you'll be able to work with - PNG, PSD, JPEG, TIFF, GIF and more.