The Advanced image settings can be accessed from the screen which is available prior to the rendering by clicking on the “Advanced options” button.
There are several options to be set.
For tile formats in command-line, see the MapTiler manual.
The produced tiles can be saved in one of several image format. MapTiler includes optimization of the final file size and uses a number of colors (quantization) to minimize the disk size occupied by the rendered maps as well as optimize the data transfer between clients and server once the tiles are served online.
Formats which support transparency are:
- PNG 8-bit which is DEFAULT. Paletted RGBA PNG image
- PNG 32-bit
Non-transparent formats are:
- Progressive JPEG image in the YCbCr color space
- Paletted RGB PNG image
- 24-bit RGB PNG image
You can also set the output format quality, which can save the space on your hard drive.
If you need to render generate hybrid tile format (where tiles are different formats, one with transparency and one without), check the MapTiler manual.
Detailed information about resampling methods is available in MapTiler manual.
The visual quality of the output tiles is also defined by the resampling method. Selected method is used for interpolation of the values of individual pixels and it affects the sharpness vs smoothness of the produced maps.
- DEFAULT. Bilinear resampling (2x2 pixel kernel)
- Nearest neighbor resampling. Rarely makes sense for production data. Can be useful for quick testing, since it is much faster than the others.
- Cubic convolution approximation (4x4 pixel kernel).
- Cubic B-Spline Approximation (4x4 pixel kernel).
- Average computes the average of all non-NODATA contributing pixels. (GDAL >= 1.10.0)
- Mode resampling selects the value which appears most often of all the sampled points. (GDAL >= 1.10.0)
For transparency settings in command-line, see MapTiler manual.
This option is typically used to eliminate borders of multiple map sheets that are stitched together. You can set a specific color of the map to be considered fully transparent during rendering.
If you set the “Ignore alpha channel (4th band)” check button on, the alpha channel from input images will be ignored.
Detailed information about tiling scheme is available in MapTiler manual.
- Open GIS WMTS / Open Street Maps / Google XYZ (top-left origin)
- OSGEO TMS (bottom-left origin)
- Microsoft Bing QuadKey (top-left origin)
For sparse settings in command-line, see MapTiler manual.
MapTiler supports switch between “sparse” and “non-sparse” option.
If Sparse output (no empty tiles) is turned on, the MapTiler skip the empty space between separate maps and don’t create empty tiles during rendering. This option can improve the speed of rendering if there are huge areas between maps. This is the default option for rendering into Folder.
If Sparse output (no empty tiles) is turned off, the MapTiler fills the empty space between separate maps (if there is some) with empty tiles in a background color. This option can take longer to render and take more disk space, if there are huge areas between maps, as these have to be created. This is the default option for rendering into MBTiles and GeoPackage.