When creating pictures, you should consider the overall quality that users expect. Since the pictures appear on an electronic screen, users may expect the pictures and screen design to fall somewhere between the standards set by television and computer arcade games. It is important to try to meet users’ visual expectancy since the impact of poorly designed images can cause users to lose interest.
An important difference between printed images and online images is their resolution. The resolution of paper-based images is generally much higher than images on the computer screen.
Don’t use images with too much detail at a small scale since the detail will likely be lost on the screen. Conversely, an enlarged image which is only partly visible can add another dimension to screen presentation.
Watch out for “staircasing” on lower resolution monitors. This is the stepped effect caused when displaying sloping lines. It can be avoided by using only vertical and horizontal lines and alleviated with lines at 45 degrees.