Image Optimization: what is it, why is it necessary, and how do I do it?

Image optimization is the processing of compressing (or reducing the file size) of graphics (especially photographs) for display on web pages.

When you view a webpage on the internet, copies of all the graphics used to display the page are downloaded and stored temporarily on your computer. If the web page you are viewing contains a lot of photographs (eg, in photo galleries) the amount of time it will take to fully display the page will depend on the optimized file size of all the photos.

Photo files from digital cameras by default use a very high resolution (the "pixels") to ensure that the image is very sharp when it is printed. This means these files (usually jpg's) from digital camers are about 2-3 mb in size. These jpg's need to be optimized before they are displayed on a web-page, where the high resolution required by printing isn't an issue.

You can optimize your photo images easily using the Microsoft Office Picture Manager (installed by default with Microsoft Office). Click here for step-by-step instructions on how to do this.

There are also various easy-to-use software packages available for download that can do this for you:

  • Snagit from TechSmith, priced at approximately US$49.95 per copy. This program also includes a lot of other functionality, including a very flexible and configurable screen capture utility.
  • A reliable "free" (for non-commercial use) application is Multiple Image Resizer. The commercial license is UK£15.00. A little more complicated to use than Snagit, and doesn't include as many additional features, but resizes/optimizes images for web use efficiently.