Normally I would create an Image Pyramid using gdal_retile.py on one large image or a set of large images.

I want to do the opposite. I have all the zoomed in tiles on the base level and I want to build (mosaic) my tiles into the rest of the levels required to build a pyramid. As GIS-Jonathan assumes I want to have the lower resolution tiles for zooming out.

                      ^      <- I want these
                     /_\     <-      :
                    /___\    <-      :
                   /_____\   <-      :
                  /_______\  <- I want these
                 /_________\ <- I have this level!

Can this be done using GDAL or similar?

I guess this would be the same as interupting gdal_retile.py just when the lowest level is finished and telling it to continue from the next level. But I don't know if this is possible?

  • I'm not clear on what you want to do or why. Are you saying you have a collection of images that form the lowest-resolution level of a pyramid, and you want to generate higher-resolution levels from them? – MerseyViking Jun 7 '12 at 14:19
  • I take it as reading he's got the highest resolution (the super-zoomed in tiles), and wants to create the pyramids for them when zoomed out (lower resolution). This is why he wants to mosaic them together. Makes sense; don't know how to do it myself though. ;-) – GIS-Jonathan Jun 7 '12 at 14:54
  • @MerseyViking: It was very clear in my head :) But outside my head it might be less clear and I have tried to graphically show what I want. – Chau Jun 8 '12 at 6:38
  • @GIS-Jonathan: You're right, but I had preferred a this is how I always do it ;) – Chau Jun 8 '12 at 6:38

a little bit complicated but you can do as follows:

  1. Merge all the tiles by making larger pieces.

  2. make all pieces coordinated with gdal_translate.

  3. create .vrt (Virtual Dataset) file with gdalbuildvrt from all coordinated pieces.

  4. use gdal2tiles for creating lower level tiles from your vrt file.

i hope it helps you...

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