- The image should always be viewable in it's entirety. The user should
not have to scroll the image to view the entire image.
- If you wish to provide larger images for views do so by letting them
choose the resolution.
- Minimum Screen Size
- Basically, everyone can view pictures at this size.
- The screen size is 640x480
- The viewable area of the this screen size is 475 x 325 to 610
x 325 (if expanded to full screen area)
- Standard screen size
- The "standard" screen size today is now 800x600
- The viewable area of the this screen size is 645 x 445 to 770
x 445 (if expanded to full screen area)
Available Number Of Colours (or Colors for US)
- 16 bit (thousands) of colours can safely be assumed to be available. Some
older system and laptops may only be able to deal with 256 colours.
- 24 bit (millions) of colours are common on newer systems and higher end
GIF's vs JPEG's vs PNG's
- You can safely assume all WWW browsers (except text ones) can show GIF files inline.
- All but the first generation WWW browsers can show JPEG's inline as well.
- PNG support requires Internet Explorer 4.0 or better or Netscape communicator
4.0.4 or better.
If more than one image is viewable on the screen at the same time, then
they must share the colours that are available. For systems with millions
of colours, this is not an issue. For systems with thousands it generally
does not become an issue. It is only an issue with systems with 256 colours.
Warning The User
If you are going to use large images and they require a certain number of colours to really be viewable, let the user know. For example, on an intro page or a "test screen", tell the user the requirements. You could also give examples, such as a box, and ask them to set they window size so that they can see all of it.