CHANGELOG.md

Changelog

All notable changes to this project are documented here. The format follows Keep a Changelog and the project adheres to Semantic Versioning.

1.1.0 - 2026-08-13

Added

• ocrsmith fetch-fonts — downloads open-licensed families from Google Fonts on demand. Font diversity is the highest-impact lever in synthetic text data, and a repository should not ship other people's typefaces. Only permissively licensed directories of google/fonts are used (ofl, apache, ufl), every family's licence file is downloaded beside its fonts, and a manifest records exactly what was taken so a dataset stays reproducible.
• Variable-font expansion. Roughly half the Arabic families on Google Fonts are variable, and a variable font renders only its default instance — so light, regular and bold of such a family all collapsed onto the same face. Families are now expanded into their named instances via font_variations / load_font(..., variation=...), and Face carries the instance alongside the file.
• DocumentContent.all_text, covering table cells and list items.

Measured on the bundled fonts plus one fetch-fonts --subset arabic run: 11 -> 57 families, 101 -> 381 drawable faces, including 13 display and calligraphic families of the kind that synthetic corpora usually lack entirely.

Note for non-Raqm builds: only 16 of the 105 fetched files carry Arabic presentation forms, so the coverage gate (fixed in 1.0.2) correctly rejects most of them. Installing Pillow with Raqm raises the usable pool from 85 to 203 faces.

1.0.2 - 2026-08-13

Fixed

• Font coverage was checked against the wrong string, so Arabic could render as tofu. Coverage was judged on the logical text, but without Raqm the renderer draws Arabic presentation forms (U+FE70-FEFF). A modern OpenType face such as Fustat or Mada covers the base Arabic block while carrying no presentation-form glyphs at all — it joins letters via GSUB instead — so the probe reported 100% coverage and every glyph then rendered as an empty box, with the label still claiming the text. FontPool now shapes before probing, using the same shaper the renderer will use. Raqm builds are unaffected and correctly keep judging the logical form.
• The coverage probe missed table cells and list items. A table block's own text is empty; its content lives in the cells. An invoice whose prose was four words therefore chose a font on the strength of those four words and drew its entire table as tofu. Added DocumentContent.all_text, which includes cells and list items, and the pipeline now probes against it.
• The font fallback silently discarded the guarantee. When no face covered a document, the pipeline fell back to the entire pool and could hand the document a face that cannot draw its script at all. It now falls back to the single best-covering face.

Found by rendering sample documents and looking at them — every automated check passed while the images were visibly broken.

1.0.1 - 2026-08-13

Fixed

• Shaping was 68% of generation time. arabic-reshaper 3.0.0 guards its ligature-regex cache with hasattr(self, '__ligatures_re'), but writes the cache to self.__ligatures_re — which Python mangles to _ArabicReshaper__ligatures_re inside the class body, while the string literal passed to hasattr is not mangled. The guard therefore checks a name that is never set, and every call rebuilt the regex, re-reading ~290 configparser entries. Laying out one page called it ~1,800 times.

  Two mitigations, both contained to ocrsmith.text.shaping: results are cached (shaping is a pure function of the string), and the reshaper's cache is warmed once so the library's own guard fires from the second call. 2,000 distinct strings: 26s -> 0.36s.

Changed

• Wrapping now measures a line the way the renderer draws it — summing word advances plus space advances — instead of measuring the whole candidate line as one shaped run. This is a correctness improvement as well as a speed one: the two could previously disagree about where a line ends. It also keys the measurement cache on words, which repeat, rather than on line prefixes, which never do.

Test suite runtime: 95s -> 20s. Generation throughput on a mixed Arabic corpus improved ~1.6x end to end; the remaining cost is genuine rasterisation and degradation work.

1.0.0 - 2026-08-12

The first release of OCRSmith as a document forge rather than a line-image generator. The v0 engine produced one image with one string; v1 produces whole pages with word-level boxes, typed layout regions, table structure and markup ground truth, and validates every page before it reaches the dataset.

Added

• ocrsmith.quality: validation and statistics.

  • Six validators for the failures that do not raise — blank pages, washed-out text, boxes off the canvas, overlapping blocks, illegibly small lines, empty labels. Each explains itself, so a rejection rate is diagnosable rather than merely alarming.
  • The generation pipeline runs them as a gate; a shard that rejects more than quality.max_rejection_rate aborts, because that is a configuration problem and a shard full of holes would hide it behind a plausible-looking dataset.
  • DatasetStats accumulates the distributions that define a corpus — templates, capture conditions, direction, region types, alphabet, line-height percentiles — in constant memory, and renders a dataset-card fragment.

• ocrsmith.evaluation: CER, WER, normalised edit similarity, TEDS-style table similarity and IoU-thresholded detection P/R/F1, plus a harness that scores a model's predictions against a generated benchmark. Diacritic sensitivity is an explicit argument rather than a silent convention.

• ocrsmith.domain.page_from_dict and friends: annotations round-trip, so validation, statistics and evaluation all read the same records the writers produce.

• CLI: validate, stats and evaluate.

• ocrsmith.pipeline: streaming generation.

  • SampleFactory.create(index) derives a per-sample seed from (config.seed, index) and yields one annotated Sample per page. Any sample can be regenerated on its own, without replaying the run that produced it.
  • iter_samples is a generator end to end, so a ten-million-page run holds one page in memory at a time.
  • Work is sharded, and each worker writes its own shard rather than shipping images back through a pickle queue. Completed shards are marked, so an interrupted job resumes instead of restarting.

• ocrsmith.datasets.writers: six output formats behind one SampleSink protocol — jsonl, parquet, webdataset, coco (word/line/region instances), paddleocr (detection labels plus line crops) and chat (image + instruction + Markdown answer for vision-language fine-tuning). Sinks write incrementally, so a killed run leaves valid shards rather than one truncated file.

• ocrsmith.config: a single validated GenerationConfig describing a whole corpus, with every per-sample choice expressed as a distribution. Dotted-key CLI overrides (--set run.workers=8) and a JSON-serialisable payload that crosses the process boundary intact.

• New ocrsmith CLI (typer + rich): generate, preview, fonts, doctor, show-config. doctor reports whether this machine can produce correct Arabic; the CLI forces UTF-8 output so a cp1252 Windows console cannot crash a tool whose entire purpose is Arabic text.

• ocrsmith.core.degradations: capture-condition modelling, where every degradation takes the annotation as well as the image and returns both.

  • Geometric: Rotation and PerspectiveWarp derive an explicit forward point mapping and push the whole annotation through it, so boxes track the ink instead of drifting silently. Rotated words gain polygons.
  • Photometric: gaussian noise, paper grain, defocus and motion blur, brightness, contrast, JPEG artefacts, downscaling, ink spread/erosion, bleed-through, shadow, vignette, glare, stains and folds.
  • Five presets — clean, scan, photo, fax, archive — ordered along the physical capture chain, so a corpus can be composed by capture condition rather than by undifferentiated noise.

• ocrsmith.core.documents: a document engine that produces full pages, not single lines.

  • DocumentBuilder / DocumentContent separate what a document says from how it looks, so the same content laid out in one column or two yields identical markup ground truth.
  • PageSpec.from_paper derives the canvas from paper size and DPI, with margins, multi-column layout (right-first for RTL) and reserved header/footer bands.
  • DocumentRenderer pours blocks down columns and onto further pages, splitting prose and moving structure whole. Nothing is clipped, nothing overlaps, and pages can be streamed one at a time.
  • TableRenderer emits per-cell boxes, content-derived column widths, in-cell wrapping, RTL column mirroring, and five border styles.
  • TypographySampler samples one coherent font family per document with per-role sizes and spacing, rather than a random face per block.
  • Six document genres (article, report, newspaper, letter, form, invoice) behind a weighted TemplateRegistry.

• ocrsmith.core.rendering: a text renderer that emits pixels and their annotation in the same pass, so the two cannot disagree.

  • Words are drawn individually, which yields exact per-word boxes and is typographically safe for Arabic (letters never join across a space).
  • visual_word_order implements word-level bidi run reordering, so mixed Arabic/Latin/digit lines are drawn in the right place while the label stays logical.
  • Wrapping is lossless: no word is silently dropped, oversized words are broken rather than overflowed, and lines that do not fit the height budget are reported so the label can be trimmed to exactly what was drawn.
  • TextStyle covers alignment (including natural RTL), line/word spacing, stroke, underline, strikethrough, synthetic bold/italic, and baseline/word-gap jitter, with an injectable random.Random so any sample is reproducible.

• ocrsmith.text: a text subsystem that owns everything happening to a string before it becomes pixels.

  • Script and base-direction detection (detect_script, detect_direction).
  • NormalizationPolicy — opt-in, idempotent transforms for diacritics, tatweel, alef/ya/ta-marbuta unification, numeral systems and whitespace. Each one changes the label, so each one is explicit and recorded.
  • Bidi/shaping with two interchangeable backends: TransparentShaper when Pillow has Raqm, ReshaperBidiShaper (arabic-reshaper + python-bidi) otherwise. Both keep the logical string as the label so datasets are identical across machines.
  • Font glyph coverage via fontTools cmap (supports_text, fonts_supporting), so a font that cannot draw a character is rejected instead of silently emitting tofu.

• Development tooling: ruff lint/format configuration, pytest configuration with pythonpath = ["src"] (so a clean clone is testable without installing), coverage settings, and a GitHub Actions CI matrix over Linux/Windows and Python 3.10/3.12.

• CONTRIBUTING.md describing the TDD workflow, branch naming, and release process.

• Regression tests covering rendering without layout constraints.

Changed

• pyproject.toml: dependency pins relaxed to compatible ranges, heavy tabular and Hugging Face dependencies moved into the data extra, project metadata and URLs completed.
• HuggingFaceTextLoader accepts any iterable of mappings, streams records via iter_texts, and defers the datasets import to call time.

Removed

• The v0 engine and everything coupled to it: OCRSmithEngine, core/app.py, the four *Manager classes, and the augmentation, text_renderers, text_placement, backgrounds and fonts strategy packages. Their responsibilities now live in core/rendering, core/documents, core/degradations, core/fonts.py, core/backgrounds.py and pipeline/, with word-level ground truth throughout.
• ocrsmith.utils, whose remaining helpers had no callers.

Fixed

• wrap_text_by_pixels raised TypeError when layout.max_width / layout.max_height were unset, which made every sample fail for configs that omit them.
• Whitespace-only input no longer produces a zero-sized canvas.