Where They Started

To preserve and extend the usefulness of its records and images — typically paper or mylar drawings measuring 24”x36” — Rockville scans them to TIFF images using a large-format scanner.

Originally all documents, whether color or grayscale, were scanned at 1 bit per pixel for more efficient use of storage space, quicker transfer over networks, and easier online access. But while 1-bit scanning reduced file sizes, it made preserving color or even grayscale drawings impossible and sacrificed considerable image detail. Plus, the resulting image files did not display very well in the city’s many installed ArcView 3.2 viewers.

Their Goals

  • Reduce file size of scanned engineering drawings
  • Retain image quality
  • Increase file access and transfer speeds


The MrSID wavelet-based technology underlying GeoExpress offers efficient compression without loss of image quality. The City of Rockville is able to preserve color information at its full 24 bits per pixel for an average file size of only 6MB in MrSID format, whereas the same file would measure 100MB uncompressed. Similarly, grayscale images preserved at the full 8 bits per pixel go from an average of 33MB uncompressed to just 2MB as MrSID files.

In addition, the floating license capability and License Manager in GeoExpress enabled Rockville to install GeoExpress on the local machine (client) of any team member who needed to perform image processing or compression, no matter how infrequently. The License Manager distributes a temporary license to a particular client at the time of use, allowing multiple simultaneous users (up to the number of purchased licenses).

The Results

  • Greater Value in Smaller Files: The City of Rockville now serves color and grayscale versions of its documents with all image detail preserved and at greatly reduced download times.
  • Easier Viewing Online: MrSID images display better than 1-bit TIFFs in Rockville’s legacy GIS viewers, and the smaller file sizes make transfer time and download much quicker for the city’s GIS users.
  • Greater Flexibility and Efficiency in Image Processing: GeoExpress made the City of Rockville’s image processing workflow more flexible and enabled them to use storage resources more efficiently.


Image Details Preserved


Download Times


Storage Efficiency

See GeoExpress in Action

Watch a Demo

+ Customer Testimonial

People are going to be looking at these documents on computer screens and also downloading them for printing. We wanted to make sure we retained the image quality attributes they would need in both situations.

- Marc Weinshenker

Next Steps

Enhance Your Geospatial Imagery

Create the exact image you need with the powerful suite of editing tools in GeoExpress to crop, color balance, reproject, mosaic, decompress to other file types, and more.


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