Sketchup

1. Install Cygwin and select Netpbm
2. Convert the image from png to pnm:

   	 pngtopnm < ../06TCmap2.png > 06TCmap2.pnm
   	

3. Dice it:

   	pamdice -outstem 06TCmap2_256 -width=256 -height=256 < 06TCmap2.pnm
   	

Scripts

subdivide2

Takes an image, subdivides it until the image size is less than 256 bytes. Each image is also resampled to 256x256. The sub images are put into directories 0, 1, 2, 3 with layout

     0  1
     2  3

Note that the images/ subdirectories can be removed after subdivide2 runs

dicekml

traverses the directories created by subdivide2.

Sample Usage

1. Edit subdivide2 and set the subdivide2 variable to the location of the subdivide2 script. We do this because subdivide2 calls itself recursively.
2. Edit dicekml and set the dicekml variable to the location of the dicekml script. Again, we do this because dicekml calls itself recursively.
3. Invoke subdivide2, creating the subdirectories:

       subdivide2 CompositeMerged.png
   

   Tuning tip: Ideally, the image is an even multiple of 256 pixels and is square. If not, you can adjust the sizes to which the model is scalled and the size at which we subdivide again. For example, a large image divides down to 359x307, so we scale it to that size and only subdivide if the image is larger than that size:

      if [ $newWidth -gt 359 -o $newHeight -gt 307 ] ; then
          (cd $ext; $subdivide2 img.png)
      fi	    
      # Scale to the smallest tile size
      mogrify -scale 359x307 $ext/img.png
   

4. Convert the initial image to its tile by using the Imagemagick "convert" utility.

       convert -scale 256 CompositeMerged.png img.png
   

   If, under Windows, convert fails to start up, you may need to adjust the path:

       export PATH=/usr/X11R6/bin:${PATH}
   

   Note that 256x256 is the magic number if your image size divides by 256. An alternative is to resize it so that it is the same size as the smallest tile that is produced by subdivide2. Continuing with our example one would:

       convert -scale 359x307 CompositeMerged.png img.png
   

5. Invoke dicekml, creating the doc.kml files First, update dicekml by changing

        minLodPixels=270
   

   to the value of the size of the tiles. For example, my tiles came out to be 180x153, so I set minLodPixels to 180+(180/2). An alternative would be change subdivide2 so that it does not create images less than 307 pixels in size.

   Then, run dicekml:

       dicekml 40.78698240735224 40.75238209417149 -119.1995634988887 -119.2439715775522
   
   

6. Clean up the images directories created by subdivide2

       find . -name "images" -exec rmdir {} \;
   

7. Create a top.kml file and update the lat and lon.