IIPImage is an Open Source
light-weight client-server system for the remote viewing of very
high-resolution images. It is designed to be bandwidth and memory
efficient and usable even over a slow internet connection. The system
is fast because the client only needs to download the portion of the
whole image that is visible on the screen of the user at their current
viewing resolution. The client requests a view of an image and the
server only needs to send back the image tiles necessary for that
particular view. This makes it possible to view, navigate and zoom
around very large images that would be impossible to download and
manipulate on the local machine. It also makes the system very scalable
as the image tile downloads will take the same regardless of the size
of the source image. In addition, to reduce the bandwidth necessary
even further, the tiles sent back are dynamically JPEG compressed with
a level of compression that can be optimized for the available
bandwidth by the client. In this way it is possible to view extremely
large gigapixel images in real-time over the internet.
In order for the system to be as efficient as possible, the images
are stored in the multi-resolution TIFF tiled pyramidal format. This
allows the server to extract regions of the full image at different
resolutions very quickly with little processing overhead. Image of
several gigapixels in size can be stored on a central server and viewed
by many different users without the need to download large amounts of
data.
The system was originally devised by the National Gallery in London and the University of Southampton for the Viseum (1996) and Acohir
(1999) EU projects. The aim of these projects was to create a system
for viewing very high resolution colorimetric museum images over the
internet. In the case of Acohir, to extend the system to handle 3D
object sequences. A published paper describing this work is available online.
The current versions of the software, though, have been completely
rewritten since then. This kind of system, though, is also applicable
to other areas such as geographical informations systems or medical
imaging.
Java Image Effects
