如何将GIS栅格转换为矢量多边形？

Question

如何将栅格GIS文件（tiff）转换为.json？

Bostock's example使用some JSON data来提供他的D3.geom.contour plugin。但是如何将一个GIS栅格，比如一个11px / 15px的小图像转换为JSON。

最终.JSON代码如下：[编辑：这不是topojson格式]

[
[103,104,104,105,105,106,106,106,107,107,106],
[104,104,105,105,106,106,107,107,107,107,107],
[104,105,105,106,106,107,107,108,108,108,108],
[105,105,106,106,107,107,108,108,109,109,109],
[105,106,106,107,107,108,108,109,109,110,110],
[106,106,107,107,107,108,109,109,110,110,111],
[106,107,107,108,108,108,109,110,110,111,112],
[107,107,108,108,109,109,110,110,112,113,114],
[107,108,108,109,109,110,111,112,114,115,116],
[107,108,109,109,110,110,110,113,115,117,118],
[107,108,109,109,110,110,110,112,115,117,119],
[108,108,109,109,110,110,110,112,115,118,121],
[108,109,109,110,110,111,112,114,117,120,124],
[108,109,110,110,110,113,114,116,119,122,126],
[108,109,110,110,112,115,116,118,122,124,128]
]

注意：.shp到.json：已经有a tutorial on how turning shapefiles into lighter topojson，但对此没有用。

Answer 1

我认为你不能直接做到这一点，这可能只是一个步骤：

过程

转换.tiff - ＆gt; .shp

gdal_contour -a elev input.tif output.shp -i 10.0

转换.shp - ＆gt; .json（ topojson ）

topojson input.shp -o output.json 

资源

• 了解TopoJSON Command Line;
• Tutorial: Working with Terrain Data in QGIS指出GDAL公用事业;
• gdal_contour从栅格高程模型构建矢量轮廓线。