Creating OAM imagery with virtual datasets (VRT)
Analog of Creating OpenAerialMap Imagery but using gdal VRTs to save disk space:
1 export GDAL_TIFF_INTERNAL_MASK=YES
2 gdalbuildvrt -srcnodata '159 0 80' prewarp.vrt Clear-Borders-No-Transparent.tif
3 gdalwarp -co TILED=YES -dstalpha -t_srs EPSG:4326 -of VRT -multi prewarp.vrt warped.vrt
4 gdal_translate -co TILED=YES -co JPEG_QUALITY=80 -co COMPRESS=JPEG -co PHOTOMETRIC=YCBCR -b 1 -b 2 -b 3 -mask 4 -of GTiff warped.vrt final.tif
5 gdaladdo final.tif 2 4 8 16 32 64 128 256