Raster File

Use the Raster File Conversion tool to process georeferenced images. This tool allows you to perform datum transformation, coordinate reprojection, and file format conversion in a single step.

File Importing

Click Open File to choose a raster file for processing. See Supported File Formats for the list of compatible file types.

After your file has finished loading, click the icon to open the Raster Preview Window to view the image's metadata and a preview image.

Information on Cloud Storage and Processing

Click Open URL in the Vector and Raster File Conversion tools to connect to data files stored in Azure and Amazon AWS S3 cloud storage accounts.

Data can be transferred directly from and to the cloud account. The size of local files uploaded directly through the browser is limited by available browser memory. Azure cloud storage connections utilize a Share Access Signature (SAS) link method, while AWS S3 connections use a presigned link method.

Output File Options

After processing, files are automatically downloaded to your computer in the file location determined by your browser settings. The default option is often the Downloads folder. Consult your browser settings to determine or change the download path. Files are generally stored in the Process Manager up to seven days while the user’s session is active. To clear output files from the Process Manager, use the “X” button to the right of each output to remove individual files, or use the blue “Clear” button to remove all output files in the list.

• Output File extension - Choose the desired file format type to export the completed raster conversion data. Only output formats compatible with the input format will be shown. The chosen output format can be the same as the input format.
• Define Output Filename - Leave this field blank unless you would like to change the name of your output file. If left blank, the input filename will be used as the base of the output filename.Use the arrow button to toggle between adding a Suffix or Prefix:
  • Add Suffix - Use this option to add a suffix to the original file name. The default is "_output".
  • Add Prefix - Use this option to add a Prefix to the original file name. The default is "output_".

Unlike point and point file conversions, most vector and raster file conversions are not performed in the browser. Files are zipped, sent to, and processed on one of three virtual machines as determined by file size.

Source and Target Coordinate Systems

Select your source and target coordinate reference systems. If processing a loaded file, the source coordinate system will populate using coordinate reference system information from the loaded data file if available. Custom Coordinate Systems can be added in Settings > Custom Datasource.

1. Under Source Coordinate System, click to open the Select Source System dialog and select the coordinate system that corresponds to the data to be converted. Filter the search by entering text or browse the Coordinate Systems folders. Use the icon to view system information.
   • The default Source Coordinate System is WGS 84(EPSG:4326); this can be changed in Settings > General. Recently used coordinate systems will populate the Source Coordinate System dropdown.
   • The units for the source and target systems will be automatically populated with the units defined in the selected objects. You may optionally search for and change the source or target units for the calculation.
2. To perform a vertical transformation on elevation data, additionally make sure the source Vertical Coordinate System is set. 
   • If a vertical CRS is detected in the loaded file or from an included external reference file, the cloud application will provide the Vertical CRS system and unit fields. 
   • In cases where height geometry is detected, but there is no recognized information on a vertical CRS, then the Unknown Vertical Coordinate System will be loaded. Use to search the datasource and select a vertical CRS.
   • Vertical systems or units cannot be chosen if the file is not detected to have elevation values.
3. The Date field will display if time-dependent transforms are enabled in settings. A date must be entered on both the Source and Target coordinate systems for time-dependent transforms to display in the available selection choices.
4. Set the Target Coordinate System using the same steps as above. 
   • Additionally, make sure to set the desired target vertical coordinate system (if using).
   • For time-dependent transformations, make sure to set a Target Date.

Select a Coordinate Transformation

If you select input and output coordinate systems that are based on different datums, you will need to select a Coordinate Transformation. If no valid transformations are found between the two datums, the Coordinate Transformation box will display "No Choices". A null transformation "<None>" can be selected by enabling the setting "Allow null transformations ("<None>" option). Custom Coordinate Transformations can be added in Settings > Custom Datasource.

1. Use "Click to select a Transform" or to search the datasource for a valid transformation between the selected Source and Target systems. 
2. In the Select Transformation dialog window, type into the Search field to limit the results by text or expand the folders on the left side to view transformations. The transformations are limited by Source and Target CRS selections (and input coordinate range if AOU filtering is enabled in settings).
   • The Datasource Transformations folder will contain any predefined objects organized into subfolders by transformation type (Concatenated, Datum, and Parametric).
   • The Generated Transformations folder will contain any on-the-fly concatenated transformations organized into subfolders based on the intermediate datums.
3. Click on the desired transformation’s name to select it. The Select Transformation dialog window will close automatically and the selected transformation will be shown
4. Repeat for vertical transformation if needed. 

Processing Files

Click the Process button to convert the data and download the new output file. 

Output files from finished conversions are listed in the Process Manager. 

Use the Clear button to remove the loaded data.

Raster Preview Window

The Raster Preview Window provides a detailed overview of your loaded file, including spatial properties and visual previews. After your file has finished loading in the Raster File Conversion tool, click the icon next to the uploaded file to open the Raster Preview Window.

The values displayed reflect the current georeferencing settings within the application, which may differ from the metadata stored in the original source reference file. 

Raster File Metadata:

• Pixel resolution, or pixel size, for both X and Y directions.
• Image width and height, measured in the number of pixels in each direction
• Elevation minimum and maximum values
• Coordinate and Vertical Reference Systems
• Reference file name
• Table of referenced corner coordinates with the corresponding column/row (0,0)