There are a large number of programs that can be used to manipulate graphics. These vary from Microsoft Paint which is supplied with windows and can only manipulate BMP files through shareware programs such as Jasc Paintshop Pro to top end graphics programs such as Adobe Photoshop which is packed full of features for professional image manipulation and has a price to match.
Each of the graphics programs serves a different purpose. For creating images to be placed on the internet, Paintshop Pro has some particularly easy to use functionality for adjusting the resolution and file size of images.
This article written by Stephen Chapman, Felgall Pty Ltd.