mapbox中的sdf图片png

在 MAPBOX 中与 SDF 的交互，更改符号层中图标的颜色，您必须提供 SDF(专用 png)格式才能实现。( https://docs.mapbox.com/mapbox-gl-js/style-spec/layers/#paint-symbol-icon-color )

Imagemagick:https://imagemagick.org/script/download.php . ImageMagick 允许你用一个命令来做到这一点:
convert in.png -filter Jinc -resize 400% -threshold 30% \( +clone -negate -morphology Distance Euclidean -level 50%,-50% \) -morphology Distance Euclidean -compose Plus -composite -level 45%,55% -resize 25% out.png