pillow-wmf

A Windows Metafile reader/writer/renderer for Pillow.

Like in the old Windows days, a GDI backend draws graphics and can also record actions to a Windows Metafile. Rasterizing one of these WMFs is just a matter of playing it back, which produces a Pillow Image.

Links

• 🏠 home
• 😺 source
• 🐍 pypi

Usage

from PIL import Image
import pillow_wmf  # registers the WMF loader ahead of Pillow's built-in stub

with Image.open("drawing.wmf") as image:
    image.load(size=(640, 480))
    image.save("drawing.png")

Rendering limits

render(data, size, limits=Limits(...)) bounds input bytes, records, points, objects and saved DC states. max_bitmap_pixels limits each decoded bitmap or glyph. max_geometry_points (default 1,000,000) limits cumulative curve flattening and dynamic pen expansion, including their stroke caps, joins and repeated realizations. Input polygon points, fixed-size stroke bodies and fixed-table pens (including their caps and joins) do not spend this expansion budget. Pen realization and identical stroke coverage are reused within one drawing operation. Reusing them does not spend the allowance again; subsequent operations generate and charge their own geometry. The geometry allowance belongs to the raster context and is not restored by RestoreDC. Each flattened curve also has a fixed 65,536-point limit. RasterContext accepts max_objects, max_saved_states, max_bitmap_pixels and max_geometry_points for direct drawing. render() passes its Limits object's object/save allowances to the backend; Pillow loading uses the defaults. Default policy values are defined in pillow_wmf.limits.

Resource exhaustion raises pillow_wmf.binary.ResourceLimitError, including during play(..., strict=False); it is never treated as a recoverable omission. An execution-time failure makes the context unusable and may leave partial pixels. Pillow reports rendering resource failures as OSError. These limits bound particular allocations and generated geometry, not total rendering time.

Drawing diagnostics

RasterContext and Recorder retain requested calls by default for existing diagnostic callers. Pass trace_calls=False to omit that history; WMF recording, handle validation and saved drawing state still work. RecordingContext also accepts this option for its own history, independently of its two backends. render() and the Pillow loader disable call history because they only return pixels. TraceContext remains the backend for collecting a command trace.

License

pillow-wmf is WTFPL with one additional clause:

1. Don't blame me.

Fonts have their own licenses, rip them out if you don't want to comply:

• Wingdings fallback (OFL-1.1)
• Wine Symbol (LGPL-2.1-or-later)