Random notes about ArcGIS Image Server - Released with ArcGIS 9.2 late last year. Recall, imagery is a natural background for many GIS apps. Useful for direct interpretation, statistics and analysis, used for vectorization (80% of vector data collected using imagery backdrop), data verification after GIS analysis. Diff. apps have diff demands on their imagery – time, quality, sun angle, etc…
Why Image Server??
Use of imagery growing exponentially
Available from many sources (aerial cameras, scanned maps, satellites)
Depth of imagery increasing, more bands of imagery, higher resolution, overlap in imagery (same image from multiple dates or diff. angles)
Imagery is often available but simply not accessible (obviously Google Earth has addressed this)
Fast access to imagery and metadata
Much more! See ArcGIS Image Server – Author, Serve, Use… Random Notes from the ESRI UC for more on this