The pypdfium rasterizer was producing output images that differed by 1
pixel compared to Ghostscript due to floating-point precision issues in
dimension calculations.
Root cause:
- pypdfium used harmonic mean of x/y DPI to calculate a single scale
factor, losing the distinction between x and y DPI
- No DPI rounding like Ghostscript's 6-decimal precision
- Compound rounding errors when converting points to pixels
Solution:
1. Round DPI to 6 decimals to match Ghostscript's precision
2. Calculate expected output dimensions using separate x/y DPI values
3. Handle dimension swapping for 90°/270° rotations
4. Resize output image if off by 1-2 pixels (graceful correction)
This ensures pixel-perfect matching with Ghostscript while being
minimally invasive and only resizing when necessary.
Changes:
- Modified _render_page_to_bitmap() to calculate expected dimensions
- Modified _process_image_for_output() to correct small discrepancies
- Updated rasterize_pdf_page() to pass dimensions through pipeline
- Parametrized rotation tests to run with both rasterizers
All 45 rotation tests now pass with both pypdfium and ghostscript.
Fixes test_rotated_skew_timeout with pypdfium rasterizer.
Migrate watcher.py and pdf_text_diff.py from typer to cyclopts for
CLI argument parsing. Update pyproject.toml to reflect the dependency
change in the watcher optional feature.
Establish clear separation between user-facing optional dependencies
and developer-only dependency groups:
**Optional Dependencies (user features):**
- watcher: File watching service for batch processing
- webservice: Streamlit-based web UI
- Installable via: uv sync --extra <name> or pip install ocrmypdf[name]
**Dependency Groups (developer tools):**
- test: Testing infrastructure (merged from test + extended_test)
- docs: Documentation building tools
- streamlit-dev: Enhanced Streamlit development tools
- dev: General development tools (mypy, ipykernel)
- Installable via: uv sync --group <name> (uv only, NOT pip)
Breaking changes for developers:
- pip install -e .[test] no longer works → use uv sync --group test
- pip install -e .[docs] no longer works → use uv sync --group docs
- pip install -e .[extended_test] removed → merged into test group
No breaking changes for end users:
- pip install ocrmypdf[watcher] still works
- pip install ocrmypdf[webservice] still works
Updated:
- CI/CD workflows to use uv sync --group test
- Docker images to exclude test dependencies
- Documentation to recommend uv with pip as fallback
- pyproject.toml with clear comments explaining both systems
- Update pipeline to use fpdf2 renderer as default
- Remove legacy hocrtransform PDF renderer (_font.py, _hocr.py,
pdf_renderer.py)
- Update CLI and options for fpdf2 renderer
- Add fpdf2 dependency to pyproject.toml
- Update graft module for fpdf2 multi-page rendering
In 0.12.1, Typer was significantly reorganized.
- `typer-slim` is the library (for `import typer`)
- `typer-slim[standard]` adds optional dependencies (currently `rich`
and `shellingham`, basically equivalent to the old `typer[all]`)
- `typer-cli` is the `typer` command-line tool
- `typer` is now basically a metapackage that brings in *all of the
above*, and it no longer has an `all` extra
Pip will warn about this and proceed,
```
WARNING: typer 0.12.1 does not provide the extra 'all'
```
but there are other tools that will fail hard when asked to resolve a
(now) nonexistent extra.
Since this project doesn’t need the `typer` command-line tool, it looks
like changing the dependency to `typer-slim[standard]` is the best way
forward.
See https://typer.tiangolo.com/release-notes/#0121 and
tiangolo/typer#785 for further discussion
and details.
James R. Barlow
Chris MayoandGitHub
Ben BeasleyandGitHub