GeoExpress Case Study – Maine Department of Transportation

State DOT Saves Storage Space and Speeds Up Image Distribution Using GeoExpress

MrSID-compressed imagery allows us and our customers to use smaller data file sizes with fewer images and without sacrificing image quality.

Richard Coffin
Engineering Technician
Maine Department of Transportation

 
Background

The Maine Department of Transportation (MaineDOT) Photogrammetry and Control Unit is charged with making aerial imagery available to the department’s other internal agencies for planning needed in transportation studies and for public communications, as well as to internal engineers and various contractors for the state. Efficiency in file storage, image processing and end-user accessibility are key to fulfilling the unit’s mission.

GeoExpress Case Study – Maine Department of Transportation

The new Exit 113 connecting Interstate 95 with Maine's Route 3 handles much of the highway freight and tourist traffic passing between the Northeastern U.S. and the eastern Canadian provinces. Original photo scale is 1:2,400.

Challenges

MaineDOT receives raw aerial image data through contracted flights and from Maine GIS (MEGIS), then processes the imagery to add georeferencing and other value and compresses it for online distribution and storage. In addition to this data, the unit has been working through a backlog of 40,000 older, paper-based aerial images, which must be scanned to TIFF from original contact prints.

MaineDOT’s workflow solution needed to achieve the following:

  • Reduce file size of stored images
  • Provide easy image manipulation such as reprojection, mosaicking, color balancing and compression in an efficient workflow
  • Retain high image quality even at compression ratios of 12:1 or 20:1
  • Enable fast and easy viewing by end-users
 
Solution

MaineDOT uses the compression and image processing tools in LizardTech’s GeoExpress software to convert TIFFs of spring- and fall-flown aerial imagery to the industry standard MrSID format. “MrSID-compressed imagery allows us and our customers to use smaller data file sizes with fewer images and without sacrificing image quality,” says Richard Coffin, engineering technician for MaineDOT. “We’re also able to process images more quickly with GeoExpress’ improved image manipulation and editing capabilities.”

Benefits

MaineDOT realized the following benefits using LizardTech’s GeoExpress:

  • Reduced storage requirements - 960 GB of imagery reduced in file size to 80 GB
  • Workflow efficiency - Combined image manipulation tools and compression capabilities
  • Retention of image quality - Visually lossless images even at compression ratios between 12 – 20:1
  • Reduced bandwidth requirements - More efficient online delivery of large image products to customers
  • Easy online viewing - All MrSID images viewable via ExpressView Plug-in