Database Connection
GeoPackage File
The path to the destination GeoPackage file.
Overwrite Existing Database
- If this option is unchecked (default) and a database already exists, then tables and features are written to the existing database.
- If this option is checked, any existing database is deleted before writing begins.
If no database exists when writing begins, a new database is created.
Note: After a database is deleted, it cannot be recovered – all data is lost.
Tile Format Parameters
Tile Format
The data format of the binary tile data stored in the tile table:
- Auto (Default)
- PNG
- PNG8
- JPEG
- WEBP
- TIFF
If the tile format is Auto, then the writer will use:
- PNG for color tiles with transparency, or for integer coverage tiles
- JPEG for opaque color tiles
- TIFF for floating-point coverage tiles
If the tile format is WEBP, then the gpkg_webp extension will be registered in the GeoPackage.
If the tile format is TIFF, then the gpkg_2d_gridded_coverage extension will be registered in the GeoPackage, and only single-band Real32 rasters will be written.
JPEG/WEBP Compression Level
This option sets the desired compression level of the JPEG or WEBP tiles. This is expressed as a percentage from 0 to 100, where 0 indicates the least possible compression (largest data size) and 100 indicates the maximum possible compression (smallest data size).
Default: 25
Note: 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.
PNG Compression Level
This option sets the PNG DEFLATE compression level.
Must be a value from 1-9. The default is 6.
PNG8 Dither
When Tile Format is PNG8, this parameter determines if PNG8 data will use Floyd-Steinberg dithering.
- Yes: PNG8 data will be written using Floyd-Steinberg dithering.
- No (default): No dithering will be used.
Tiling Scheme Parameters
Tiling Scheme
Determines the tiling scheme used to convert a raster to tiles. Coordinate systems and the divisions of zoom levels can vary among tiling schemes:
|
Option |
Description |
|---|---|
| GoogleMapsCompatible (default) |
The tiling scheme made popular by Google Maps. Uses a projected (Mercator) coordinate system with an approximation of the WGS84 Ellipsoid as a sphere. Uses a single 256x256 tile as zoom level 0. |
|
GoogleCRS84Quad |
Uses a geodetic coordinate system (LL-WGS84) and a single 256x256 tile extending from [-180,180] in both axes as zoom level 0. May be incompatible with some applications due to inconsistency in extents of zoom level 0. |
| InspireCRS84Quad |
Uses a geodetic coordinate system (LL-WGS84) and a two 256x256 tiles as zoom level 0 (one for each hemisphere). |
| PseudoTMS GlobalGeodetic |
Based on OSGeo global_geodetic tiling scheme. Differs from the OSGeo TMS (Tile Map Service) specification because the GeoPackage specification numbers tiles from the top-left corner while the TMS specification numbers from the bottom-left. |
| PseudoTMS GlobalMercator |
Based on OSGeo global_mercator tiling scheme. Differs from the OSGeo TMS (Tile Map Service) specification because the GeoPackage specification numbers tiles from the top-left corner while the TMS specification numbers from the bottom-left. |
| Use Incoming Feature |
Instead of a standard tiling scheme, uses incoming raster extents and resolution as basis for tiles. |
All the tiling schemes mentioned above subdivide tiles into four quadrants with each increasing zoom level.
Interpolation Type
Determines the resampling algorithm used when constructing tile data:
|
Option |
Description |
|---|---|
|
Bilinear (default) |
Calculates a pixel's value by averaging the closest 2x2 neighborhood of pixel values. This method produces a higher-quality result than Nearest Neighbor. |
|
Nearest-neighbor |
Nearest-neighbor interpolation uses the value of the nearest pixel to calculate the value of a given pixel without considering the values of pixels outside this nearest pixel range. Nearest-neighbor is the least resource-intensive, but also produces the lowest-resolution tiles. |
|
Cubic |
Calculates a pixel's value by using the closest 4x4 neighborhood of pixel values. |
|
Cubic-spline |
Because it calculates a pixel's value by using a spline, this results in a smaller error than linear interpolation, and the interpolation is smoother. |
|
Lanczos |
Use Lanczos interpolation when you want to enhance or maintain local contrast; it is useful for viewing detailed features or boundaries. |
|
Mode |
This is a custom resampling algorithm made by GDAL. This method will select the value which appears most often in all the sampled pixels and use that as the value for the given pixel. |
|
Average |
This is a custom resampling algorithm made by GDAL. This method will use the average of all non-NODATA contributing pixels to compute the value of a pixel. |
Base Zoom Level Strategy
The GeoPackage Tiles writer writes raster data at a particular zoom level that is related to the resolution of the raster. This option sets the strategy used to determine the zoom level:
|
Option |
Description |
|---|---|
|
Auto (default) |
Round the zoom level to the closest integer value when computing the resolution to determine the zoom level. |
|
Upper |
Round the zoom level down when computing the resolution to determine the zoom level. For example, round 4.25 to 5. This will lead to oversampling. |
|
Lower |
Round the zoom level up when computing the resolution to determine the zoom level. For example, round 4.75 to 4. This will lead to undersampling. |
Generate Zoom Levels
Determines whether to create additional zoom levels by resampling the original raster:
|
Option |
Description |
|---|---|
|
Yes |
The writer generates zoom levels from the level below the Base Zoom Level, as determined by the Base Zoom Level Strategy parameter. It continues to generate less-resolute zoom levels until it hits the level specified in the Minimum Zoom Level parameter (described below), or until it is impossible to generate less-resolute zoom levels. The interpolation type used to resample the generated zoom levels is controlled by the Interpolation Type parameter. |
|
No (default) |
Only the base (closest to native image resolution) zoom level will be written. |
Minimum Zoom Level
Determines the least-resolute zoom level to generate when Generate Zoom Levels is set to Yes.
Defaults to 0, which is the lowest possible zoom level in a GeoPackage.
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 |
|---|---|---|
|
Precision |
The smallest cell value that has meaning for the tiled gridded coverage. |
1 |
|
Grid Cell Encoding |
Describes how the value of each cell is related to the bounds of the cell. Standard values include:
|
grid-value-is-center |
|
Unit of Measure |
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. |
|
|
Field Name |
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 |
|
Quantity Definition |
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
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.