From 8dd968c7ced6368d94c949e7d531623aa67c64b1 Mon Sep 17 00:00:00 2001 From: Dane Springmeyer Date: Fri, 4 Oct 2013 12:06:27 -0700 Subject: [PATCH] link to image_util.cpp --- Image-IO.md | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/Image-IO.md b/Image-IO.md index 1fa1875..581a56e 100644 --- a/Image-IO.md +++ b/Image-IO.md @@ -3,7 +3,7 @@ Mapnik supports reading and writing a variety of image formats. These formats can be used as: - Output formats for rendered map tiles - - Input formats for symbols or icons for symbolizers like the `MarkersSymbolizer` + - Input formats for symbols or icons for symbolizers like the [[MarkersSymbolizer]] - Input formats for the [[Raster]] datasource plugin. Note: if you are looking for what raster geodata formats are supported see also what the [[GDAL]] datasource plugin supports. ## Format strings @@ -41,6 +41,9 @@ In Mapnik >= 2.3.x by default: - PNG output is paletted png with no greater than 256 colors (aka. `png8`) - JPEG output uses a `quality` of 85. - TIFF output uses `PHOTOMETRIC_RGB` and `COMPRESSION_DEFLATE` + - WEBP output uses `WEBP_HINT_GRAPH` as an `image_hint` to indicate to the encoder that the image is likely a discrete tone image (this may change in the future) and otherwise uses WEBP encoder defaults. + +See the C++ [image_util.cpp](https://github.com/mapnik/mapnik/blob/master/src/image_util.cpp) file for definitive defaults that are set for various encoders (as this wiki page may become out of date). ### TIFF output options @@ -78,4 +81,4 @@ And the key:value options can be controlled as follows: | s | string, `default`, `filtered`, `huff`, or `rle` | `default` | Not likely that you need to change this option. It is the ZLIB compression strategy. See zlib docs for more details (available in Mapnik >= 2.x) | | e | string, `miniz` or `libpng` | 'libpng` | Experimental: not recommended to set this option. `e=miniz` triggers using the experimental miniz encoder support instead of `libpng`. In some cases this encoder provides better encoding speeds with minor size differences but it also does not work fully yet (bugs we need to track down) | -### WEBP output options +### WEBP output options \ No newline at end of file