Feature to skip partial tiles

[caleb87]

What would it take to skip edge tiles that are partially blank (and fully blank)?

I'm trying to tile many tifs that overlap, and I don't see how I can get full tiles in the overlap areas. Merging tifs won't work, because the output file will be terabytes in size.

The original gdal2tiles (https://github.com/OSGeo/gdal/blob/master/gdal/swig/python/scripts/gdal2tiles.py) has a part to skip fully blank tiles, but I haven't figured out how to detect partial tiles and implement it into gdal2tilesp yet.

       alpha = alphaband.ReadRaster(rx, ry, rxsize, rysize, wxsize, wysize)

        # Detect totally transparent tile and skip its creation
        if tile_job_info.exclude_transparent and len(alpha) == alpha.count('\x00'.encode('ascii')):
            return

        data = ds.ReadRaster(rx, ry, rxsize, rysize, wxsize, wysize,
                             band_list=list(range(1, dataBandsCount + 1)))

[roblabs]

What would it take to skip edge tiles that are partially blank (and fully blank)?

It sounds like your problem has nothing to do with the gdal2tiles.

Things to consider (whether using this repo or the official OSGeo version)

• How does tiling of your TIFs work with Maptiler.com? That is a more fully featured version with support
• Are you using gdalbuildvrt to create the tile? If so, can you use some logic to skip blank edge tiles?
  • We use this tool to create .vrt files for input into gdal2tilesp processing.

From the command line help

e.g.
  % gdalbuildvrt doq_index.vrt doq/*.tif
  % gdalbuildvrt -input_file_list my_list.txt doq_index.vrt

[caleb87]

Rob thanks for the input!

I have a tif with no alpha edges (it's rectangle), but the tiles still produce partial alpha due to the alignment of the tiles.

Original (Scaled down to low quality jpg)

Tile Cuts

Map Tiler and gdal2tiles output the same. They skip fully blank tiles (when there are huge alpha areas), but I haven't found a way to skip partial tiles.

BTW I'm using gdal_merge which is working well, but I'll look into gdalbuildvrt.