convert WMF or EMF to KML

[ecp98rjs]

I have a file in windows metafile format that I would like to import into google earth. It seems only to support raster images, which gives poor quality or very large file sizes.

Is there a way to convert a WMF file into a KML, KMZ, or some other vector format that Google Earth understands?

Thanks,
Rob

[smcq]

I have to make a lot of assumptions because you don't say how you intend the image to appear.

Are you trying to make an overlay? In that case you need to convert the WMF to a bitmap format. PNG works best, as it compresses and it allows alpha transparency. If your vector shapes should appear as an overlay without a background color, convert to PNG. The quality is good.

Are you trying to create polygons in GE from WMF vectors? Then you will need SketchUp to import the vector art then export it to GE. I'm not sure if SketchUp imports WMF but it does import Illustrator, converting splines to polygons.

It is natural to assume that polygons clamped to ground will look better than overlays, but this is not necessarily the case. To conserve memory when there are a lot of polygons clamped to ground, GE rasterizes them very coarsely, resulting in a low resolution bitmap.

If my assumptions are on the mark, I suggest you go the PNG route. You will need a photo editor that exports 24 bit PNG with alpha transparency.

SMcQ

[ecp98rjs]

I want the image to appear as an overlay. It is a very fine detail thematic map of deprivation in the UK at super output area level (about 35,000 different areas).

I tried a high-res PNG image (about 10,000 by 10,000 pixels) but this shows nothing like enough detail and GE really slows to a crawl when I load it. I think I really need it to import in vector format.

Thanks,
Rob

[smcq]

Check out this post and see if it gives you any ideas about going the shapefile route. Also, GE Pro and SketchUp can import shapefiles.

If you have a great big PDF map that you want to plop into GE as an overlay, I don't know of any other vector route than to meticulously convert to shapefiles.

One thing I've found out from PNGs with alpha transparency is that they are much smaller files than the pixel dimensions would suggest. In an overlay with transparency, most of the image area will not count toward file size. I'm guessing that your 10K square image used no transparency.

You can also tile overlays, and even overlap them, making sure the drawing order is correct.

SMcQ

[ecp98rjs]

Hi.

Thanks, I'll have have a go at alpha transparency. The file I have was created in Mapinfo originally, but the Mapinfo2google tools does not do thematic maps (it is a fantastic tool for doing outlines although kml filesizes it generates can be huge).

Rob