OGC GeoPackage Tiles Writer Parameters

The path to the destination GeoPackage file.

• 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.

The data format of the binary tile data stored in the tile table.

Can be either:

• Auto (Default)
• PNG
• PNG8
• JPEG
• WEBP

If the tile format is Auto, then the writer will use PNG for tiles with transparency and JPEG for opaque tiles.

If the tile format is WEBP, then the gpkg_webp extension will be registered in the GeoPackage.

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.

This option sets the PNG DEFLATE compression level.

Must be a value from 1-9. The default is 6.

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.

Determines the tiling scheme used to convert a raster to tiles. Coordinate systems and the divisions of zoom levels can vary among tiling schemes:

• 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.

Determines the resampling algorithm used:

• Bilinear (default): Use the Bilinear interpolation algorithm to construct the tile data. 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: Use the nearest-neighbor interpolation to construct the tile data. 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: Use the cubic interpolation algorithm to construct the tile data. Calculates a pixel's value by using the closest 4x4 neighborhood of pixel values.
• Cubic-spline: Use the Cubic Spline interpolation algorithm to construct the tile data. 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 the Lanczos interpolation algorithm to construct the tile data. Use Lanczos interpolation when you want to enhance or maintain local contrast; it is useful for viewing detailed features or boundaries.
• Mode: Use the Mode resampling method to construct the tile data. 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: Use the average resampling method to construct the tile data. 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.

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:

• 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.

Determines whether to create additional zoom levels by resampling the original raster:

• If 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.
• If No (default), only the base (closest to native image resolution) zoom level will be written.

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.