On some wallpaper websites, there is an option to download the wallpaper in different Resolutions. For example in the following screenshot, the same wallpaper is available in different res. I want to know how this is done, Is it done like, when someone upload an image, that is resized in all the different sizes and kept in folder so that anyone can download? (eg. 1 image has 4-5 copies of different sizes) Or. only orignal image is uploaded, and when someone click on the sizes, it resize at that time and offer to download? (in this way, we don't need to make 4-5 copies of an image and store on server, which saves lots of space.)
usually, such kind of things programmers do during upload.. after upload of original size image, programmers create the thumnails via scripting... i have also done this alot of times.. below are some examples.. http://www.webdevelopmenthouse.com/wallpaper-script http://www.webdevelopmenthouse.com/wallpaper-website-script