qc of imagery with fme at manitoba hydro
DESCRIPTION
Presented by Sarah Wach and Rob Gerry of Manitoba HydroAbstract:Manitoba Hydro has been using FME for over eight years as an everyday processing tool. Recently we have begun to create more complex workbenches to deal with the greater demands of the data we are processing. Digital ortho image quality control has always been a time consuming process, much more so now with the increase in file sizes due to increasing resolutions. We required a tool to cut down the manual work required to determine to determine if incoming orthophotography from contractors is meeting specifications. To meet this demand we developed a FME workbench to process tiff files and output a report, a coverage grid and a degraded raster mosaic file for each dataset. The user inputs the parameters the image product is expected to meet (Tile size, resolution, coordinate system) as well as the input dataset location and the output locations and file names. The input datasets are the tiff images and a shapefile of the coverage grid which was created pre-project. The workbench determines if the tiff file is located in correct place and named correctly by comparing it to the coverage grid. It also performs tests on the raster parameters to see if they meet the user input parameters. A degraded raster mosaic is output to allow for a visual inspection of the entire dataset without the excessive processing times required to create a full mosaic. This workbench is expected to cut down on the time required to QC an incoming DOI product by days or weeks.TRANSCRIPT
QC of Imagery with FME at Manitoba HydroSarah Wach and Rob GerryGeospatial Data Services, Manitoba Hydro
April 23, 2012
FME at Manitoba Hydro
Started using early 2000’s
Data format conversions
Coordinate system transformations
NTDB formatting for ESRI SDE
Image mosaics/compression
Day to day data processing
Production mode for parcel fabric updating
Best Available Digital Ortho Imagery
• 56 data sources
• Air Photo & Satellite
• 10cm to 15m resolution
• color & greyscale
• ~ 4 TB’s and growing
• 7 areas
• 6600 Sq. Km’s
• 1090 tiles
• 2 aircraft
2011 DOIAcquisition
Testing Parameters
Proper naming (eg. 51061010) Horizontal Datum (NAD83 – zone 14) Tile Size (2.5 km sq.) Image Resolution (20cm) Colour Balance Georeference
Inputs
Uses published parameters to make the workbench reusable and user friendly
Testing Values
Information for naming the output files
Locations for the Sources and Destinations
Test for Tiff Naming
Test for Datum and Tile Size
Test for Image Resolution
Low Resolution Raster Creation
Outputs
CSV file with results of the tests Shapefile with the tiff bounding boxes Low resolution ecw file
Results
Prior to the FME workspace only a few tiles out of a dataset would have been checked
Enables a complete QC process
Creates a record of the QC process
Allows more time for visual checks
FME Applications in Development
Caribou GPS tracking collar conversion
LiDAR QC
XML metadata
Thank You!
Questions?