doc_processer/app/api/v1/endpoints/image.py

"""Image OCR endpoint."""

from fastapi import APIRouter, Depends, HTTPException

from app.core.dependencies import get_image_processor, get_layout_detector, get_ocr_service, get_mineru_ocr_service
from app.schemas.image import ImageOCRRequest, ImageOCRResponse
from app.services.image_processor import ImageProcessor
from app.services.layout_detector import LayoutDetector
from app.services.ocr_service import OCRService, MineruOCRService

router = APIRouter()


@router.post("/ocr", response_model=ImageOCRResponse)
async def process_image_ocr(
    request: ImageOCRRequest,
    image_processor: ImageProcessor = Depends(get_image_processor),
    layout_detector: LayoutDetector = Depends(get_layout_detector),
    mineru_service: MineruOCRService = Depends(get_mineru_ocr_service),
    paddle_service: OCRService = Depends(get_ocr_service),
) -> ImageOCRResponse:
    """Process an image and extract content as LaTeX, Markdown, and MathML.

    The processing pipeline:
    1. Load and preprocess image (add 30% whitespace padding)
    2. Detect layout using DocLayout-YOLO
    3. Based on layout:
       - If plain text exists: use PP-DocLayoutV2 for mixed recognition
       - Otherwise: use PaddleOCR-VL with formula prompt
    4. Convert output to LaTeX, Markdown, and MathML formats

    Note: OMML conversion is not included due to performance overhead.
    Use the /convert/latex-to-omml endpoint to convert LaTeX to OMML separately.
    """

    image = image_processor.preprocess(
        image_url=request.image_url,
        image_base64=request.image_base64,
    )

    try:
        if request.model_name == "mineru":
            ocr_result = mineru_service.recognize(image)
        elif request.model_name == "paddle":
            ocr_result = paddle_service.recognize(image)
        else:
            raise HTTPException(status_code=400, detail="Invalid model name")
    except RuntimeError as e:
        raise HTTPException(status_code=503, detail=str(e))

    return ImageOCRResponse(
        latex=ocr_result.get("latex", ""),
        markdown=ocr_result.get("markdown", ""),
        mathml=ocr_result.get("mathml", ""),
        mml=ocr_result.get("mml", ""),
    )