Files
OCR-SPRIN-SERVICE/src/ocr_sprint/pipeline/orchestrator.py
Devin AI d0e1835cc1 Phase 2: document detection + perspective correction + shadow removal
Adds OpenCV-based phone-photo handling that runs before the standard
preprocessing pipeline for IMAGE source kinds (PDF renders are flat by
construction and skip this stage).

Pipeline additions in src/ocr_sprint/pipeline/document_detect.py:
- _find_document_quad: Canny + dilate + contour search, picks the
  largest convex 4-point polygon above a configurable area threshold;
  fails gracefully and returns None when no usable quad is found.
- _four_point_warp: orders corners (TL/TR/BR/BL via sum/diff trick)
  and runs cv2.getPerspectiveTransform + warpPerspective.
- _remove_shadow: per-channel background-division (dilate + median
  blur + 255 - absdiff + normalize) for uneven phone-shot lighting.
- detect_and_correct: top-level entrypoint with graceful fallback
  to the original image when detection fails.

Wired into the synchronous orchestrator: only enabled for IMAGE
sources, skipped for PDF. New settings:
- preprocess_detect_document (default: true)
- preprocess_remove_shadow (default: true)
- preprocess_min_quad_area_fraction (default: 0.20)

Tests: 9 new unit tests covering corner ordering, quad detection on
synthetic skewed documents, perspective warp output sanity, shadow
removal shape preservation, full-pipeline behavior, and graceful
fallback when detection fails. 70 tests total, all green.

ML-based dewarping (DewarpNet) and DocTR detector are deferred to a
future phase per the roadmap; the existing API is structured so they
can be added as alternative backends behind DocumentDetectConfig.

Co-authored-by: adrian kuman firmansah <adriancuman@gmail.com>
2026-04-25 15:06:58 +00:00

113 lines
3.9 KiB
Python

"""Synchronous pipeline orchestrator (Phase 1).
Wires the individual stages together:
bytes → ingest → preprocess → OCR → regex extract → validate → score
Phase 4 will replace this with a Celery task graph; Phase 3/5 will plug
in PP-Structure for tables and an LLM extractor for variant fields.
"""
from __future__ import annotations
from dataclasses import dataclass
from ocr_sprint.config import get_settings
from ocr_sprint.pipeline.confidence import compute_confidence, route
from ocr_sprint.pipeline.document_detect import DocumentDetectConfig, detect_and_correct
from ocr_sprint.pipeline.extract.regex_rules import extract_header, find_signatory
from ocr_sprint.pipeline.extract.validators import validate_extraction
from ocr_sprint.pipeline.ingest import detect_source_kind, ingest
from ocr_sprint.pipeline.ocr import OCRPage, run_ocr
from ocr_sprint.pipeline.preprocess import PreprocessConfig, preprocess
from ocr_sprint.schemas.document import DocumentStatus, SourceKind
from ocr_sprint.schemas.extraction import ExtractionResult, ReviewFlag
from ocr_sprint.utils.logging import get_logger
_logger = get_logger(__name__)
# Below this OCR confidence we automatically flag for review.
_OCR_CONFIDENCE_FLAG_THRESHOLD = 0.80
@dataclass
class PipelineOutput:
"""Bundle returned by the orchestrator."""
source_kind: SourceKind
status: DocumentStatus
confidence: float
result: ExtractionResult
def run_pipeline(content: bytes) -> PipelineOutput:
"""Execute the synchronous OCR + extraction pipeline on raw upload bytes."""
s = get_settings()
kind = detect_source_kind(content)
if kind == SourceKind.UNKNOWN:
raise ValueError("Unsupported file type — only PDF and common image formats are accepted.")
pages = ingest(content, kind, target_dpi=s.preprocess_target_dpi)
_logger.info("pipeline.ingested", source_kind=kind.value, pages=len(pages))
pre_cfg = PreprocessConfig(
max_side=s.ocr_max_image_side,
denoise=s.preprocess_denoise,
deskew=s.preprocess_deskew,
adaptive_threshold=s.preprocess_adaptive_threshold,
)
# Document detection only makes sense on photographed images. PDF renders
# are already flat by construction, so we skip the heavy quad search there.
detect_cfg = DocumentDetectConfig(
detect_document=s.preprocess_detect_document and kind == SourceKind.IMAGE,
remove_shadow=s.preprocess_remove_shadow and kind == SourceKind.IMAGE,
min_area_fraction=s.preprocess_min_quad_area_fraction,
)
ocr_pages: list[OCRPage] = []
for page in pages:
corrected = detect_and_correct(page.image, detect_cfg)
cleaned = preprocess(corrected, pre_cfg)
ocr_pages.append(run_ocr(cleaned))
full_text = "\n".join(p.text for p in ocr_pages)
mean_ocr_conf = sum(p.mean_confidence for p in ocr_pages) / len(ocr_pages) if ocr_pages else 0.0
header = extract_header(full_text)
ttd = find_signatory(full_text)
initial_flags: list[ReviewFlag] = []
if mean_ocr_conf < _OCR_CONFIDENCE_FLAG_THRESHOLD:
initial_flags.append(ReviewFlag.LOW_OCR_CONFIDENCE)
result = ExtractionResult(
header=header,
personel=[], # Phase 3 will populate from PP-Structure
untuk=[],
ttd=ttd,
raw_text=full_text,
confidence=mean_ocr_conf,
review_flags=list(initial_flags),
)
flags = validate_extraction(result)
# merge initial OCR-confidence flag with validation flags, preserving uniqueness
seen = set(flags)
for f in initial_flags:
if f not in seen:
flags.append(f)
seen.add(f)
result.review_flags = flags
final_conf = compute_confidence(mean_ocr_conf, flags)
result.confidence = final_conf
status = route(final_conf)
return PipelineOutput(
source_kind=kind,
status=status,
confidence=final_conf,
result=result,
)