The JPEG come
in two flavours, a plain JPEG file and a Progressive jpg. The latter
are similar to Interlaced gifs wherein the image is displayed in
the browser in a series of passes.
In contrast
to gifs, JPEG images can contain 16.7 million colors (24-bit color
information). Also, JPEG images do not use palettes like GIF image
and cannot have transparency. JPEG image do not support animation,
though you'll can make an animated jpg banner using a little JavaScript.
JPEG images
can be created using any of the standard image editing and manipulation
programs available. These software also let you control the compression
levels (which we'll discuss very shortly) in the JPEG.
For the Internet,
the resolution of JPEG images should be reduced to 72 dpi, since
this is the maximum resolution most monitors have. JPEG images usually
carry .jpg extension; though rare, you might also come across .jpeg.
