Using an ArcIMS image service in ArcMap, why is the resolution of my plot so poor?

In ArcMap, if you are using an ArcIMS Image Service such as the Indiana Spatial Data Service (ISDS) and print to a large format plotter, you may notice the resolution on the resulting plot is granular and of poor quality. This problem is a known limitation with ESRI's ArcIMS.

The setting for image resolution that resides on the ArcIMS server directly influences the print quality in ArcMap on the client side. When you view images from an ArcIMS service, the server-side application sends images (as .png, .gif, or .jpg files, depending on the service configuration) to your computer that are limited to 96 dots per inch (dpi). This is fine for viewing images on a monitor or printing to a desktop printer. However, when a layout is sent to a plotter at 300 dpi, the ArcIMS 96 dpi limit results in a low resolution, pixelated plot.

Increasing the ArcIMS image setting (on the server side) to 300 dpi would cause the service to perform extremely slowly on the web or in ArcMap, resulting in higher redraw times when viewing the images. For this reason, UITS has decided to keep the 96 dpi limit to make the ISDS more efficient.

To work around this problem, you can download the master TIFF images to make the plot. These are available from the Indiana Spatial Data Portal at:

Also see:

• At IU, where can I get help with GIS or remote sensing?
• How do I use ArcGIS to connect to the Indiana Spatial Data Service?
• At IU, what spatial data resources are available?
• How do I install the ISDP Multi-file Download Tool?