[gdal-dev] Building Overviews for Tiles of Large images

[Cole, Derek]

Hello again,

I am reading over some of the documentation and information I can find on GDAL.

I have some pretty large NITF images that I want to break up for purposes of displaying in a viewer I am developing. My current plan is to tile the images into 1024x1024 blocks. The full images are 32768x32768 pixels

I was hoping that as part of my tiling, I would read in the image blocks and display them as they are on disk, and as a user zoomed out, switch to "Less detailed" versions the further out they go.

I was looking at the gdaladdo sample program. Is this what I want to be looking at to try to replicate this functionality *in memory* for my viewer? Ideally all of the tiles would know what level of zoom they were at, and switch to the appropriate level of detail accordingly.

Does it sound feasible to have my code constantly switching each tile between an overview that is generated on the fly like that, or do people typically write out the lower res imagesonce to file , and re-read that new files?

Thanks for answering!

Derek
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/gdal-dev/attachments/20110611/13875d5a/attachment.html