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Vane Data / Reference

Image functions

Image functions decode, inspect, transform, and encode IMAGEFILE and IMAGE values. The connection's image_backend (python by default, native with the loaded native_media extension) selects the Pillow/tifffile/imagecodecs path or the C++ path; EXPLAIN shows native_* names for native plans. Every function and accessor in the table has a Python form, an Expression method form, and a SQL form. Python returns a lazy vane.Expression; name it with .alias(...).

Choose an API

FunctionPythonSQLNative implementationReturns
image_file_metadata✓✓native_image_file_metadataMetadata STRUCT
decode_image_file✓✓native_decode_image_fileIMAGE
decode_image✓✓native_decode_imageIMAGE
crop✓✓native_cropIMAGE
resize✓✓native_resizeIMAGE
convert_image✓✓native_convert_imageIMAGE
encode_image✓✓native_encode_imageBLOB
image_hash✓✓native_image_hashFIXEDBINARY(n)
image_to_tensor✓✓—TENSOR
Image accessors✓✓—UINTEGER

image_file is the IMAGEFILE constructor. image_to_tensor and the accessors have no backend-specific implementation.

Python ImageFile values

vane.ImageFile exposes bound methods that always use the Python implementation:

MethodReturns
ImageFile.metadata(*, max_bytes=1048576, max_pixels=100000000)ImageMetadata
ImageFile.decode(mode=None, buffer_size=1048576, *, max_input_bytes=268435456, max_pixels=100000000, max_decoded_bytes=536870912)Decoded image (PIL Image)

metadata inspects headers without decoding; decode follows the same mode and limit rules as decode_image_file and raises on failure.

Backends

Both backends follow the same mode, format, and resource-limit rules.

  • python (default): Pillow/tifffile/imagecodecs. Install vane-ai[image].
  • native: the loaded native_media extension. Set image_backend = 'native' before binding the query. An unavailable extension fails during binding; there is no automatic fallback.
example.py
import vane


con = vane.connect()
vane.load_installed_extension("native_media", connection=con)
con.execute("SET image_backend = 'native'")

Returns and errors

NULL inputs produce NULL. Invalid coordinates, modes, formats, resource-limit breaches, missing codec dependencies, and cancellation propagate as errors. Python ImageFile failures raise ImageFileError or its ImageFileFormatError / ImageFileLimitError subclasses. Each operator accepts at most 100 million pixels and 256 MiB of pixel data per input image.

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