Mert 79d0e3e1ed
fix(ml): ocr inputs not resized correctly (#23541)
* fix resizing, use pillow

* unused import

* linting

* lanczos

* optimizations

fused operations

unused import
2025-11-03 07:21:30 +00:00

125 lines
4.8 KiB
Python

from typing import Any
import cv2
import numpy as np
from numpy.typing import NDArray
from PIL import Image
from rapidocr.ch_ppocr_det.utils import DBPostProcess
from rapidocr.inference_engine.base import FileInfo, InferSession
from rapidocr.utils import DownloadFile, DownloadFileInput
from rapidocr.utils.typings import EngineType, LangDet, OCRVersion, TaskType
from rapidocr.utils.typings import ModelType as RapidModelType
from immich_ml.config import log
from immich_ml.models.base import InferenceModel
from immich_ml.schemas import ModelFormat, ModelSession, ModelTask, ModelType
from immich_ml.sessions.ort import OrtSession
from .schemas import TextDetectionOutput
class TextDetector(InferenceModel):
depends = []
identity = (ModelType.DETECTION, ModelTask.OCR)
def __init__(self, model_name: str, **model_kwargs: Any) -> None:
super().__init__(model_name, **model_kwargs, model_format=ModelFormat.ONNX)
self.max_resolution = 736
self.mean = np.array([0.5, 0.5, 0.5], dtype=np.float32)
self.std_inv = np.float32(1.0) / (np.array([0.5, 0.5, 0.5], dtype=np.float32) * 255.0)
self._empty: TextDetectionOutput = {
"boxes": np.empty(0, dtype=np.float32),
"scores": np.empty(0, dtype=np.float32),
}
self.postprocess = DBPostProcess(
thresh=0.3,
box_thresh=model_kwargs.get("minScore", 0.5),
max_candidates=1000,
unclip_ratio=1.6,
use_dilation=True,
score_mode="fast",
)
def _download(self) -> None:
model_info = InferSession.get_model_url(
FileInfo(
engine_type=EngineType.ONNXRUNTIME,
ocr_version=OCRVersion.PPOCRV5,
task_type=TaskType.DET,
lang_type=LangDet.CH,
model_type=RapidModelType.MOBILE if "mobile" in self.model_name else RapidModelType.SERVER,
)
)
download_params = DownloadFileInput(
file_url=model_info["model_dir"],
sha256=model_info["SHA256"],
save_path=self.model_path,
logger=log,
)
DownloadFile.run(download_params)
def _load(self) -> ModelSession:
# TODO: support other runtime sessions
return OrtSession(self.model_path)
# partly adapted from RapidOCR
def _predict(self, inputs: Image.Image) -> TextDetectionOutput:
w, h = inputs.size
if w < 32 or h < 32:
return self._empty
out = self.session.run(None, {"x": self._transform(inputs)})[0]
boxes, scores = self.postprocess(out, (h, w))
if len(boxes) == 0:
return self._empty
return {
"boxes": self.sorted_boxes(boxes),
"scores": np.array(scores, dtype=np.float32),
}
# adapted from RapidOCR
def _transform(self, img: Image.Image) -> NDArray[np.float32]:
if img.height < img.width:
ratio = float(self.max_resolution) / img.height
else:
ratio = float(self.max_resolution) / img.width
resize_h = int(img.height * ratio)
resize_w = int(img.width * ratio)
resize_h = int(round(resize_h / 32) * 32)
resize_w = int(round(resize_w / 32) * 32)
resized_img = img.resize((int(resize_w), int(resize_h)), resample=Image.Resampling.LANCZOS)
img_np: NDArray[np.float32] = cv2.cvtColor(np.array(resized_img, dtype=np.float32), cv2.COLOR_RGB2BGR) # type: ignore
img_np -= self.mean
img_np *= self.std_inv
img_np = np.transpose(img_np, (2, 0, 1))
return np.expand_dims(img_np, axis=0)
def sorted_boxes(self, dt_boxes: NDArray[np.float32]) -> NDArray[np.float32]:
if len(dt_boxes) == 0:
return dt_boxes
# Sort by y, then identify lines, then sort by (line, x)
y_order = np.argsort(dt_boxes[:, 0, 1], kind="stable")
sorted_y = dt_boxes[y_order, 0, 1]
line_ids = np.empty(len(dt_boxes), dtype=np.int32)
line_ids[0] = 0
np.cumsum(np.abs(np.diff(sorted_y)) >= 10, out=line_ids[1:])
# Create composite sort key for final ordering
# Shift line_ids by large factor, add x for tie-breaking
sort_key = line_ids[y_order] * 1e6 + dt_boxes[y_order, 0, 0]
final_order = np.argsort(sort_key, kind="stable")
sorted_boxes: NDArray[np.float32] = dt_boxes[y_order[final_order]]
return sorted_boxes
def configure(self, **kwargs: Any) -> None:
if (max_resolution := kwargs.get("maxResolution")) is not None:
self.max_resolution = max_resolution
if (min_score := kwargs.get("minScore")) is not None:
self.postprocess.box_thresh = min_score
if (score_mode := kwargs.get("scoreMode")) is not None:
self.postprocess.score_mode = score_mode