[gdal-dev] gdal2tiles with GeoTIFF which crosses antimeridian?

[James Russo]

Lars,

Sorry! My apologies. Despite double checking, there was a copy and paste
error in the script. The second gdalwarp with the -te was outputting to the
same path as the no sliced version. Corrected script below. I appreciate
you looking into this with me!

*additionally, My original reply directly to you also included a typo. This
script should be good!

-jr

---snip---
#!/bin/bash

wget -SN https://aeronav.faa.gov/content/aeronav/Planning/AK_WallPlan_2.zip &&
unzip -xo AK_WallPlan_2.zip
mv "Alaska Wall Planning Chart 2.tif" Alaska_Wall_Planning_Chart_2.tif
gdal_translate  -expand rgb  -strict  -co TILED=YES -co COMPRESS=LZW  -co
BIGTIFF=YES Alaska_Wall_Planning_Chart_2.tif alaska_expanded_rgb.vrt
gdalwarp -t_srs EPSG:3857 -r lanczos -overwrite -multi -wo
NUM_THREADS=ALL_CPUS -wm 1024 --config GDAL_CACHEMAX 1024 -co TILED=YES
alaska_expanded_rgb.vrt alaska_warped.vrt
gdalwarp -t_srs EPSG:3857 -te -19979999 6016546 -13438444 11497579 -r
lanczos -overwrite -multi -wo NUM_THREADS=ALL_CPUS -wm 1024 --config
GDAL_CACHEMAX 1024 -co TILED=YES alaska_expanded_rgb.vrt
alaska_warped_sliced_at_180.vrt
rm -rf alaska_tiles_no_slice
rm -rf alaska_tiles_sliced_at_180
gdalinfo alaska_warped.vrt
time gdal2tiles.py -vvv -z 0-9 --processes=16 -r lanczos -w leaflet
alaska_warped.vrt alaska_tiles_no_slice
gdalinfo alaska_warped_sliced_at_180.vrt
time gdal2tiles.py -vvv -z 0-9 --processes=16 -r lanczos -w leaflet
alaska_warped_sliced_at_180.vrt alaska_tiles_sliced_at_180

---snip---

On Thu, Nov 26, 2020 at 9:55 AM <lars.schylberg at blixtmail.se> wrote:

> Hi,
>
> I tried to reproduce your experiment. It seems like the command that
> produces "alaska_warped_sliced_at_180.vrt" is missing in your script.
> I guess that step could be vital to understand what is going on.
>
> Best regards
>
> /Lars Schylberg
>
> 26 november 2020 kl. 03:42, "James Russo" <jr at halo3.net
> <jr at halo3.net?to=%22James%20Russo%22%20%3Cjr at halo3.net%3E>> skrev:
>
> Good Evening,
> I'm just following up on this question from a few days ago with some more
> information and the script I am using which reproduces this issue.
> The example results can be found here at the s3 links below and are all
> generated from the same original GeoTIFF. The only difference is that on
> one of them I slice off all data left of the 180, the other one the map is
> left complete. The html files are set to the same example point and zoom
> level to show how that without slicing the file, the image quality is very
> poor. The one thing I notice is that if I include the 180 meridian, the
> number of tiles generated is far larger (46k vs 8k).
> Bad Results:
>
> http://halo3.net/alaska_tiles_no_slice/leaflet.html
>
> Good Results:
>
> http://halo3.net/alaska_tiles_sliced_at_180/leaflet.html
>
> Below is the script I use to generate both tile sets. It will
> automatically download, unzip and process the input file I am using
> producing the same results shown at the links above.
> I'd appreciate any insight into the issue and how I might be able to get
> it resolved? I'm still quite a novice at all this GIS stuff, but it has
> been a fun experience so far.
> Thanks,
> -jr
> ---snip---
> #!/bin/bash
> wget -SN
> https://aeronav.faa.gov/content/aeronav/Planning/AK_WallPlan_2.zip &&
> unzip -xo AK_WallPlan_2.zip
> mv "Alaska Wall Planning Chart 2.tif" Alaska_Wall_Planning_Chart_2.tif
> gdal_translate -expand rgb -strict -co TILED=YES -co COMPRESS=LZW -co
> BIGTIFF=YES Alaska_Wall_Planning_Chart_2.tif alaska_expanded_rgb.vrt
> gdalwarp -t_srs EPSG:3857 -r lanczos -overwrite -multi -wo
> NUM_THREADS=ALL_CPUS -wm 1024 --config GDAL_CACHEMAX 1024 -co TILED=YES
> alaska_expanded_rgb.vrt alaska_warped.vrt
> gdalwarp -t_srs EPSG:3857 -te -19979999 6016546 -13438444 11497579 -r
> lanczos -overwrite -multi -wo NUM_THREADS=ALL_CPUS -wm 1024 --config
> GDAL_CACHEMAX 1024 -co TILED=YES alaska_expanded_rgb.vrt alaska_warped.vrt
> rm -rf alaska_tiles_no_slice
> rm -rf alaska_tiles_sliced_at_180
> gdalinfo alaska_warped.vrt
> time gdal2tiles.py -vvv -z 0-9 --processes=16 -r lanczos -w leaflet
> alaska_warped.vrt alaska_tiles_no_slice
> gdalinfo alaska_warped_sliced_at_180.vrt
> time gdal2tiles.py -vvv -z 0-9 --processes=16 -r lanczos -w leaflet
> alaska_warped_sliced_at_180.vrt alaska_tiles_sliced_at_180
> ---snip---
> On Tue, Nov 24, 2020 at 6:20 AM James Russo <jr at halo3.net> wrote:
>
> Good Evening,
> GIS novice here. I have a GEOTiff that I'm trying to create tiles from
> which crosses the 180. It's a FAA sectional chart from the US used for
> aviation. If I slice off anything west of the 180, I can generate the tiles
> and they look good. If I don't the area of the tiles is super large and the
> resulting tile set is very pixelated.
> The source file is located here in zip form (
> https://aeronav.faa.gov/content/aeronav/Planning/AK_WallPlan_2.zip)
> I've tried some of the solutions that specify to use the CONFIG_LONG
> option, but that doesn't seem to be impacting anything. The only solution I
> have come up with is to cut off the area which crosses the 180 which yields
> good results.
> I've included below the commands I've been using. I'm looking for any
> suggestions/guidance. I realize this is somewhat of a common problem. Even
> MapTiler had the problem, but they have sent an updated version which
> supposedly fixes it, but I can't afford that solution at this point so I'd
> like to stick to GDAL if possible.
> Thanks,
> -jr
> --- snip --
> gdal_translate \
> -expand rgb \
> -strict \
> -co TILED=YES \
> -co COMPRESS=LZW \
> -co BIGTIFF=YES \
> alaska.tif alaska_expanded_rgb.vrt
>
> gdalwarp \
> -overwrite \
> -cutline "Alaska_Wall_Planning_Chart.shp" \
> -crop_to_cutline \
> -cblend 10 \
> -r lanczos \
> -dstalpha \
> -co ALPHA=YES \
> -co TILED=YES \
> -multi \
> -wo NUM_THREADS=ALL_CPUS \
> -wm 1024 \
> --config GDAL_CACHEMAX 1024 \
> "alaska_expanded_rgb.vrt" \
> "alaska_clipped.vrt"
>
> gdalwarp \
> -t_srs EPSG:3857 \
> -te -19497422 6016546 -13438444 11497579 \
> -r lanczos \
> -overwrite \
> -multi \
> -wo NUM_THREADS=ALL_CPUS \
> -wm 1024 \
> --config GDAL_CACHEMAX 1024 \
> -co TILED=YES \
> "alaska_clipped.vrt" \
> "alaska_warped.vrt"
> gdal2tiles.py -z 0-8 --processes=16 -r lanczos -w leaflet alaska_warped.vrt
>
>
>
>
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