#!/bin/bash

GDAL_TILE_PROCESSES=16
GDAL_TILE_ZOOMS=8-14
GDAL_SAMPLING_WARP=cubic
GDAL_SAMPLING_TILE=antialias

# Create virtual dataset with coordinates
gdal_translate -of VRT -a_srs EPSG:4326 -outsize 300% 300% -gcp 0.0 0.0 26.25226655 56.86114159 -gcp 21600.0 0.0 26.26784392 56.95617404 -gcp 21600.0 22161.0 26.44035651 56.94655217 -gcp 0.0 22161.0 26.42815109 56.85570501 GX825/GX_825_SK_frame_138.jpg GX_825_SK_frame_138.vrt

# Add cutline to VRT
gdalwarp -r $GDAL_SAMPLING_WARP -tps -dstalpha -cutline_srs EPSG:4326 \
  -cutline "POLYGON(($(echo -e "1032.0 2616.0\n816.0 19536.0\n21096.0 19920.0\n21192.0 2352.0" | \
  gdaltransform -tps -output_xy GX_825_SK_frame_138.vrt | \
  awk 'NR==1{first=$0} {printf "%s %s,", $1,$2} END{print " " first}')))" \
  GX_825_SK_frame_138.vrt GX_825_SK_frame_138.cut.vrt

# Generate tiles
gdal2tiles.py -r $GDAL_SAMPLING_TILE --xyz -z $GDAL_TILE_ZOOMS -x --processes=$GDAL_TILE_PROCESSES GX_825_SK_frame_138.cut.vrt GX_825_SK_frame_138.xyz