libvips Build Surface¶

The runtime image builds libvips from source with a narrow, explicit feature set. Enabled options map to IIIF formats Triplet serves today. Disabled options either add unused source formats, text/PDF/SVG rendering stacks, dynamic module loading, or broader parser surface area.

Runtime libvips behavior is configured under vips:

vips:
  concurrency: 0
  cache_max_mem: 0
  cache_max_files: 0
  report_leaks: false
  block_untrusted: true
  blocked_operations:
    - VipsForeignLoadPdf

Image request limits live under iiif.image:

iiif:
  image:
    max_output_pixels: 100000000
    max_source_pixels: 250000000
    max_derivative_bytes: 512MiB
    max_concurrent_transforms: 4
    color_management: preserve
    load_access: auto

color_management: preserve is the default and leaves source profiles attached where the output codec supports them. normalize uses LCMS to convert supported non-sRGB color images to sRGB and strips export metadata; none skips color conversion while still stripping export metadata where supported. See Configuration for the operator tradeoffs.

Enabled¶

Option	What it enables	libvips implication
`cgif`	Native GIF save support in libvips.	Required for IIIF `gif` response/output without ImageMagick.
`imagequant`	Palette quantization support.	Required for native `gifsave_buffer`; also improves palette output quality.
`jpeg`	JPEG load/save.	Required for common IIIF JPEG source and derivative traffic.
`lcms`	Little CMS color management.	Required for optional ICC normalization. The default path preserves embedded profiles without converting unless normalization is configured.
`openjpeg`	JPEG 2000 load/save.	Required for JP2 source/input and response/output.
`png`	PNG load/save.	Required for PNG source/input and response/output.
`spng`	libspng PNG codec support.	Keeps PNG support fast and modern where libvips uses SPNG.
`tiff`	TIFF load/save.	Required for common preservation/master source images and TIFF output.
`webp`	WebP load/save.	Required for WebP source/input and response/output.
`zlib`	Deflate compression support.	Required by PNG/TIFF-related compression paths.

When vips.block_untrusted is enabled, Triplet still unblocks the libvips JPEG, PNG, WebP, GIF, JPEG 2000, and TIFF load/save operations because these are the image source and response formats Triplet intentionally serves. Operators can re-block those classes with vips.blocked_operations if their deployment does not accept a format.

vips:
  block_untrusted: true
  blocked_operations:
    - VipsForeignLoadPdf

Disabled¶

Option	What disabling means	libvips implication
`modules`	No dynamic libvips plugin modules loaded at runtime.	Improves container predictability and security; needed support is compiled in.
`introspection`	No GObject introspection metadata.	Fine; govips uses cgo bindings, not runtime GIR metadata.
`cfitsio`	No FITS astronomy image load/save.	Not needed unless serving FITS.
`exif`	No libexif metadata support.	Reduces metadata parser surface; EXIF orientation/metadata handling is limited.
`fftw`	No FFT/frequency-domain operations.	Not used for IIIF resize/crop/encode.
`fontconfig`	No font discovery.	Not needed while text rendering is disabled.
`archive`	No archive-backed pyramid/deepzoom packaging.	Not used by current handlers.
`heif`	No HEIC/AVIF load/save.	Revisit only if HEIC/AVIF source or output support is required.
`uhdr`	No Ultra HDR JPEG gain-map support.	Not needed for current IIIF output.
`jpeg-xl`	No JPEG XL load/save.	Revisit only if JXL support is required.
`magick`	No ImageMagick fallback formats.	Intentional; avoids a large dependency and parser surface.
`matio`	No MATLAB `.mat` image load.	Not needed.
`nifti`	No NIfTI medical image load/save.	Not needed.
`openexr`	No OpenEXR HDR image load/save.	Not needed.
`openslide`	No whole-slide formats such as SVS/NDPI/MRXS.	Revisit if Triplet targets pathology or whole-slide imaging.
`highway`	No Highway SIMD acceleration.	Possible performance cost; benchmark before enabling.
`orc`	No ORC vectorized/JIT pixel operations.	Possible performance cost; benchmark before enabling.
`pangocairo`	No text rendering.	Not needed unless Triplet adds labels, watermarks, or rendered text.
`pdfium`	No PDF load via PDFium.	PDF source/input stays disabled; Triplet only writes simple PDF output.
`poppler`	No PDF load via Poppler.	Same as `pdfium`; avoids PDF parser surface.
`quantizr`	No quantizr quantization backend.	Fine; native GIF output uses `imagequant`.
`raw`	No camera RAW load.	Not needed.
`rsvg`	No SVG load.	Intentional unless SVG sources become required.