OGC GeoPackage Tiles Writer Feature Type Parameters
To access feature type parameters, click the gear icon on a feature type in the workspace. This opens the Feature Type Parameter Editor.
Tip: To always display the editor in Workbench, you can select View > Windows > Parameter Editor.
General
All feature types share similar General parameters, which may include Feature Type Name, Reader or Writer information, and Geometry.
In most Writer Feature Type parameter dialogs, you can also control Dynamic Schema Definitions. Some database formats accept a Table Qualifier prefix on the output table feature type.
General
Tile Set Name
The tile set's name.
Sets the value of the name row in the metafile table.
Default to the basename of the filename.
Tile Set Creation
Tile Format Parameters
Parameter |
Description |
Default |
---|---|---|
Tile Format |
The data format of the binary tile blob data stored in the tile table. Sets the value of the format row in the metafile table if Auto is not specified.
|
Auto |
JPEG/WEBP Compression Level |
If Tile Format is set to JPEG or WEBP, this parameter sets the desired compression level of the output images. This is expressed as a percentage of the original file size. For example, setting a compression level of 75 means that the output image will be approximately 75% smaller (one-quarter of the size) than an uncompressed image. Value: The level of compression that is used, from 1-100.
Repeatedly reading and saving files may decrease the quality for this format. In addition, Workbench may not know which format data comes from, and whether it used lossy compression. If you know that source data comes from files with lossy compression, you should also set the compression level to 0. Although this compression still does not guarantee the exact copy of the source file, the output will be very close to the original. |
75 |
PNG Compression Level |
If Tile Format is set to PNG, this parameter sets the PNG DEFLATE compression level. Must be a value from 1-9. |
6 |
PNG8 Dither |
If Tile Format is set to PNG8, this parameter determines if the PNG8 data will use Floyd-Steinberg dithering.
|
No |
Tiling Scheme Parameters
Parameter |
Description |
Default |
---|---|---|
Tiling Scheme |
To enable use of GeoPackage with tile servicing software, you can select a predefined tiling scheme:
In all the above tiling schemes, consecutive zoom levels defer by a resolution of a factor of two. |
GoogleMapsCompatible |
Interpolation Type |
Determines the resampling algorithm used:
|
Bilinear |
Base Zoom Level Strategy |
Sets the strategy used to determine the zoom level:
|
Auto |
Generate Zoom Levels |
Determines whether to create additional zoom levels by resampling the original raster:
|
No |
Minimum Zoom Level |
Determines the least-resolute zoom level to generate when Generate Zoom Levels is set to Yes. |
0, which is the lowest possible zoom level |
Tiled Gridded Coverage Parameters
Tiled Gridded Coverages parameters only apply to single-band rasters with an interpretation that is one of:
- UInt16
- Int16
- Real32
These rasters will be written as a Tiled Gridded Coverage, according to the gpkg_2d_gridded_coverage extension.
Parameter |
Description |
Default |
---|---|---|
The smallest cell value that has meaning for the tiled gridded coverage. |
1 |
|
Describes how the value of each cell is related to the bounds of the cell. Standard values include:
|
grid-value-is-center |
|
The unit for cell values in the tiled gridded coverage. The value for this parameter should be a symbol from The Unified Code for Units of Measure. For example, Cel is used for degrees Celsius in a temperature coverage. If no value is specified, then the unit from the raster’s coordinate system will be assumed. |
|
|
The name that describes the data in the tiled gridded coverage. For example, a coverage of air temperature may use the field name Temperature. |
Height |
|
The description of the field of data in the tiled gridded coverage. This parameter expands upon the Field Name to add extra context or a link to a more in-depth definition. For example, the Marine Metadata registry uses the following definition for an Air Temperature field: “Air temperature is the bulk temperature of the air, not the surface (skin) temperature”. |
Height |
Advanced feature type parameters apply to a single feature type (tile set). Compare the Advanced parameters on the writer.
Temporary Database Location
Determines where to store the temporary database while processing tiles.
- On Disk (Default) – A temporary file will be created to process partial tiles. This mode is more reliable, but may be slower.
- In Memory – A temporary database will be created entirely within memory. This mode is usually faster, but may be more susceptible to failure due to lack of system resources.
Temporary Database Cache Size (MB)
Determines the size in megabytes of the cache for the On Disk temporary database. If temporary database location is In Memory, then this parameter will be ignored.
The default cache size is 2MB.
Tip: Writing speed may be improved if cache size is set to a larger amount, such as 1x or 2x the available RAM on the system.