Take the 2-minute tour ×
Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. It's 100% free, no registration required.

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?

share|improve this question
    
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

1 Answer 1

up vote 3 down vote accepted

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...

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.