Skip to content

konturio/marblecutter-tools

 
 

Folders and files

NameName
Last commit message
Last commit date

Latest commit

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Repository files navigation

marblecutter-tools

Tools to process raster data; transcoding (to COG) and metadata generation.

Usage

tk

GeoTIFF Settings

  • block size (internal tiling) is 512x512
  • sources are kept in their original CRS
  • 4-band, 8-bit sources are assumed to be RGBA; band 4 (if present) is assumed to be an alpha channel and is extracted as the mask. RGB bands are converted to the YCbCr colorspace and JPEG-compressed w/ default quality settings. Pixel interleaving is used.
  • floating-point sources are compressed using DEFLATE with a floating point predictor (3 for GDAL)
  • all other sources are compressed using DEFLATE with a horizontal predictor (2 for GDAL)
  • internal overviews are generated with the same settings and produced for factors of 2 until the overview is smaller than the block size (readers shouldn't gain much benefit beyond that even when rendering at very low resolutions)

BigTIFFs should be generated when necessary; since compression is in play, BIGTIFF=IF_SAFER is used (we added this recently after encountering a source within the threshold that GDAL's default heuristic didn't pick BigTIFF).

External Masks

External masks (.msk sidecar) are currently created; this isn't ideal, but there were a couple driving reasons for doing this in the past (which may no longer be accurate, particularly after some recent improvements to rasterio):

  • when read as masks by rasterio, [mask] overviews weren't used
  • masks should be resampled using nearest-neighbor to preserve edge crispness, even when other resampling methods (lanczos, bicubic, etc) are used for imagery bands

About

Tools to process raster data for use with marblecutter

Resources

License

Stars

Watchers

Forks

Releases

No releases published

Packages

No packages published

Languages

  • Shell 51.7%
  • Python 29.1%
  • Handlebars 9.1%
  • Dockerfile 7.1%
  • Makefile 3.0%