This is a minor addendum to the previous post on creating and placing arbitrary raster graphic images and symbols into Google Earth using GIF/PNG transparency. As my chicken scratch writing sample showed, creating quality raster graphic symbols can be a challenge for some, and while there are tools in most raster graphic editors to create high-quality test, shapes and symbols, vector drawing programs usually do a better job on those. It’s possible to use a slightly-modified version of the process in the previous post to bring symbols drawn in vector graphic software into Google Earth.
1. As before, export in image format the area of Google Earth you want to display custom graphics on top of, recording the bounds of the image.
2. Import this graphic jpg image into a vector drawing program. Adobe Illustrator is the best-known COTS program for this, but if you search around, you can find several free programs that do similar things. Examples include Inkscape, a simple, free and open source solution, and Creature House Expression 3, a commercial program now available for free that is very powerful, but has a steep learning curve.
3. Mark the corners of the imported graphic with some kind of symbols; you’ll need these as a guide to cropping later on.
4. Add your vector objects in the appropriate position on top of the raster graphic image from Google Earth.
5. When you’re finished adding vector objects, delete the raster graphic image, leaving behind the vector objects.
6. Export this image as a raster graphic (check your help file to find out how). You’ll get the best results by saving it in a lossless format like TIFF, PNG, or GIF (the last only if the image has less than 256 colors).
7. Open the new raster graphic image in your favorite raster graphic editor, and crop it using the bounds from step 3 as guides.
8. If the resulting cropped raster graphic image is large (greater than 2000 x 2000 pixels), Google Earth may have trouble dealing with it; use the resize function to shrink it down, then save it
From this point on, just follow the steps in the previous post to convert this graphic image to a GIF/PNG file with transparency, and then to place it correctly in Google Earth. Unlike the raster graphic example in the previous post, you may have to move and stretch the image a bit to get it place correctly, depending on how accurately you were able to crop it in step 7.