Images

Images

  • Images are served using a IIIF Image API 2.0-compliant server, Cantaloupe, fed JPEG 2000 images that have been compressed from source TIFFs + JPEGS.
  • Image metdata (which comes from a variety of semi-structured sources) is fetched at build time from an S3 bucket where PMA staff has collected hi-resolution TIFF files, and derived from HTTP URLs where necessary in the case of the JSON-based Navigart and PMA TMS APIs.
  • Compressed images are discovered with a SPARQL query against the integrated linked data and then compressed in a batch process.

Special considerations

  • Unexpected TIFF compression profiles

All TIFF files are forced uncompressed during normalization and bit depths are normalized to 8bpp.

  • Colorspace

Colorspaces that are not sRGB are converted during normalization.

  • Multipage TIFFs

Multipage TIFF files should be pre-processed using the data pipeline's included script (accessible from pipeline workflows stage-images).

References

  • TBD