mirror of
https://github.com/blakeblackshear/frigate.git
synced 2025-07-26 13:47:03 +02:00
detect and process dedicated lpr plates
This commit is contained in:
parent
8bf1c216bb
commit
ed1cffd4ae
@ -3,16 +3,22 @@
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import datetime
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import logging
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import math
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import random
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import re
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import string
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from typing import List, Optional, Tuple
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import cv2
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import numpy as np
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from Levenshtein import distance
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from Levenshtein import distance, jaro_winkler
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from pyclipper import ET_CLOSEDPOLYGON, JT_ROUND, PyclipperOffset
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from shapely.geometry import Polygon
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from frigate.comms.event_metadata_updater import EventMetadataTypeEnum
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from frigate.comms.event_metadata_updater import (
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EventMetadataPublisher,
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EventMetadataTypeEnum,
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)
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from frigate.embeddings.onnx.lpr_embedding import LPR_EMBEDDING_SIZE
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from frigate.util.image import area
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logger = logging.getLogger(__name__)
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@ -28,6 +34,8 @@ class LicensePlateProcessingMixin:
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"license_plate" not in self.config.objects.all_objects
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)
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self.event_metadata_publisher = EventMetadataPublisher()
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self.ctc_decoder = CTCDecoder()
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self.batch_size = 6
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@ -710,18 +718,38 @@ class LicensePlateProcessingMixin:
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top_score = -1
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top_box = None
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img_h, img_w = input.shape[0], input.shape[1]
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# Calculate resized dimensions and padding based on _preprocess_inputs
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if img_w > img_h:
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resized_h = int(((img_h / img_w) * LPR_EMBEDDING_SIZE) // 4 * 4)
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resized_w = LPR_EMBEDDING_SIZE
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x_offset = (LPR_EMBEDDING_SIZE - resized_w) // 2
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y_offset = (LPR_EMBEDDING_SIZE - resized_h) // 2
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scale_x = img_w / resized_w
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scale_y = img_h / resized_h
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else:
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resized_w = int(((img_w / img_h) * 512) // 4 * 4)
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resized_h = LPR_EMBEDDING_SIZE
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x_offset = (LPR_EMBEDDING_SIZE - resized_w) // 2
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y_offset = (LPR_EMBEDDING_SIZE - resized_h) // 2
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scale_x = img_w / resized_w
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scale_y = img_h / resized_h
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# Loop over predictions
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for prediction in predictions:
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score = prediction[6]
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if score >= confidence_threshold:
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bbox = prediction[1:5]
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# Scale boxes back to original image size
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scale_x = input.shape[1] / 256
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scale_y = input.shape[0] / 256
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bbox[0] *= scale_x
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bbox[1] *= scale_y
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bbox[2] *= scale_x
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bbox[3] *= scale_y
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# Adjust for padding and scale to original image
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bbox[0] = (bbox[0] - x_offset) * scale_x
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bbox[1] = (bbox[1] - y_offset) * scale_y
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bbox[2] = (bbox[2] - x_offset) * scale_x
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bbox[3] = (bbox[3] - y_offset) * scale_y
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if score > top_score:
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top_score = score
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top_box = bbox
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if score > top_score:
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top_score = score
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@ -729,8 +757,8 @@ class LicensePlateProcessingMixin:
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# Return the top scoring bounding box if found
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if top_box is not None:
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# expand box by 30% to help with OCR
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expansion = (top_box[2:] - top_box[:2]) * 0.30
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# expand box by 5% to help with OCR
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expansion = (top_box[2:] - top_box[:2]) * 0.05
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# Expand box
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expanded_box = np.array(
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@ -842,57 +870,54 @@ class LicensePlateProcessingMixin:
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"""
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self.metrics.alpr_pps.value = (self.metrics.alpr_pps.value * 9 + duration) / 10
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def lpr_process(self, obj_data: dict[str, any], frame: np.ndarray):
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def _generate_plate_event(self, camera: str, plate_score: float) -> str:
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"""Generate a unique ID for a plate event based on camera and text."""
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now = datetime.datetime.now().timestamp()
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rand_id = "".join(random.choices(string.ascii_lowercase + string.digits, k=6))
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event_id = f"{now}-{rand_id}"
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self.event_metadata_publisher.publish(
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EventMetadataTypeEnum.manual_event_create,
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(
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now,
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camera,
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"license_plate",
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event_id,
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True,
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plate_score,
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None,
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None,
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"api",
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{},
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),
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)
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return event_id
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def lpr_process(
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self, obj_data: dict[str, any], frame: np.ndarray, dedicated_lpr: bool = None
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):
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"""Look for license plates in image."""
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if not self.config.cameras[obj_data["camera"]].lpr.enabled:
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camera = obj_data if dedicated_lpr else obj_data["camera"]
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current_time = int(datetime.datetime.now().timestamp())
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if not self.config.cameras[camera].lpr.enabled:
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return
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id = obj_data["id"]
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# don't run for non car objects
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if obj_data.get("label") != "car":
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logger.debug("Not a processing license plate for non car object.")
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return
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# don't run for stationary car objects
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if obj_data.get("stationary") == True:
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logger.debug("Not a processing license plate for a stationary car object.")
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return
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# don't overwrite sub label for objects that have a sub label
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# that is not a license plate
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if obj_data.get("sub_label") and id not in self.detected_license_plates:
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logger.debug(
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f"Not processing license plate due to existing sub label: {obj_data.get('sub_label')}."
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)
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return
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license_plate: Optional[dict[str, any]] = None
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if self.requires_license_plate_detection:
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logger.debug("Running manual license_plate detection.")
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car_box = obj_data.get("box")
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if not car_box:
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return
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if dedicated_lpr:
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rgb = cv2.cvtColor(frame, cv2.COLOR_YUV2BGR_I420)
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left, top, right, bottom = car_box
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car = rgb[top:bottom, left:right]
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# double the size of the car for better box detection
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car = cv2.resize(car, (int(2 * car.shape[1]), int(2 * car.shape[0])))
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# apply motion mask
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rgb[self.config.cameras[obj_data].motion.mask == 0] = [0, 0, 0]
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if WRITE_DEBUG_IMAGES:
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current_time = int(datetime.datetime.now().timestamp())
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cv2.imwrite(
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f"debug/frames/car_frame_{current_time}.jpg",
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car,
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f"debug/frames/dedicated_lpr_masked_{current_time}.jpg",
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rgb,
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)
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yolov9_start = datetime.datetime.now().timestamp()
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license_plate = self._detect_license_plate(car)
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license_plate = self._detect_license_plate(rgb)
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logger.debug(
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f"YOLOv9 LPD inference time: {(datetime.datetime.now().timestamp() - yolov9_start) * 1000:.2f} ms"
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)
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@ -901,94 +926,225 @@ class LicensePlateProcessingMixin:
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)
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if not license_plate:
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logger.debug("Detected no license plates for car object.")
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logger.debug("Detected no license plates in full frame.")
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return
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license_plate_area = max(
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0,
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(license_plate[2] - license_plate[0])
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* (license_plate[3] - license_plate[1]),
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license_plate_area = (license_plate[2] - license_plate[0]) * (
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license_plate[3] - license_plate[1]
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)
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# check that license plate is valid
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# double the value because we've doubled the size of the car
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if (
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license_plate_area
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< self.config.cameras[obj_data["camera"]].lpr.min_area * 2
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):
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logger.debug("License plate is less than min_area")
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if license_plate_area < self.lpr_config.min_area:
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logger.debug("License plate area below minimum threshold.")
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return
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license_plate_frame = car[
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license_plate[1] : license_plate[3], license_plate[0] : license_plate[2]
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]
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else:
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# don't run for object without attributes
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if not obj_data.get("current_attributes"):
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logger.debug("No attributes to parse.")
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return
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attributes: list[dict[str, any]] = obj_data.get("current_attributes", [])
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for attr in attributes:
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if attr.get("label") != "license_plate":
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continue
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if license_plate is None or attr.get("score", 0.0) > license_plate.get(
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"score", 0.0
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):
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license_plate = attr
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# no license plates detected in this frame
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if not license_plate:
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return
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license_plate_box = license_plate.get("box")
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# check that license plate is valid
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if (
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not license_plate_box
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or area(license_plate_box)
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< self.config.cameras[obj_data["camera"]].lpr.min_area
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):
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logger.debug(f"Invalid license plate box {license_plate}")
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return
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license_plate_frame = cv2.cvtColor(frame, cv2.COLOR_YUV2BGR_I420)
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# Expand the license_plate_box by 30%
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box_array = np.array(license_plate_box)
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expansion = (box_array[2:] - box_array[:2]) * 0.30
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expanded_box = np.array(
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[
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license_plate_box[0] - expansion[0],
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license_plate_box[1] - expansion[1],
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license_plate_box[2] + expansion[0],
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license_plate_box[3] + expansion[1],
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]
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).clip(0, [license_plate_frame.shape[1], license_plate_frame.shape[0]] * 2)
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# Crop using the expanded box
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license_plate_frame = license_plate_frame[
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int(expanded_box[1]) : int(expanded_box[3]),
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int(expanded_box[0]) : int(expanded_box[2]),
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license_plate_frame = rgb[
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license_plate[1] : license_plate[3],
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license_plate[0] : license_plate[2],
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]
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# double the size of the license plate frame for better OCR
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license_plate_frame = cv2.resize(
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license_plate_frame,
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(
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int(2 * license_plate_frame.shape[1]),
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int(2 * license_plate_frame.shape[0]),
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),
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)
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if WRITE_DEBUG_IMAGES:
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if license_plate:
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frame_with_rect = rgb.copy()
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cv2.rectangle(
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frame_with_rect,
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(
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int(license_plate[0]),
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int(license_plate[1]),
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),
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(
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int(license_plate[2]),
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int(license_plate[3]),
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),
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(0, 255, 0),
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2,
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)
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cv2.imwrite(
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f"debug/frames/dedicated_lpr_with_rect_{current_time}.jpg",
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frame_with_rect,
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)
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if WRITE_DEBUG_IMAGES:
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current_time = int(datetime.datetime.now().timestamp())
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cv2.imwrite(
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f"debug/frames/license_plate_frame_{current_time}.jpg",
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# Double the size for better OCR
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license_plate_frame = cv2.resize(
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license_plate_frame,
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(
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int(2 * license_plate_frame.shape[1]),
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int(2 * license_plate_frame.shape[0]),
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),
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)
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if WRITE_DEBUG_IMAGES:
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cv2.imwrite(
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f"debug/frames/dedicated_lpr_doubled_{current_time}.jpg",
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license_plate_frame,
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)
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else:
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id = obj_data["id"]
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# don't run for non car objects
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if obj_data.get("label") != "car":
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logger.debug("Not a processing license plate for non car object.")
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return
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# don't run for stationary car objects
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if obj_data.get("stationary") == True:
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logger.debug(
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"Not a processing license plate for a stationary car object."
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)
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return
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# don't overwrite sub label for objects that have a sub label
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# that is not a license plate
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if obj_data.get("sub_label") and id not in self.detected_license_plates:
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logger.debug(
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f"Not processing license plate due to existing sub label: {obj_data.get('sub_label')}."
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)
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return
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license_plate: Optional[dict[str, any]] = None
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if self.requires_license_plate_detection:
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logger.debug("Running manual license_plate detection.")
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car_box = obj_data.get("box")
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if not car_box:
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return
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rgb = cv2.cvtColor(frame, cv2.COLOR_YUV2BGR_I420)
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left, top, right, bottom = car_box
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car = rgb[top:bottom, left:right]
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# double the size of the car for better box detection
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car = cv2.resize(car, (int(2 * car.shape[1]), int(2 * car.shape[0])))
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if WRITE_DEBUG_IMAGES:
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cv2.imwrite(
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f"debug/frames/car_frame_{current_time}.jpg",
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car,
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)
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yolov9_start = datetime.datetime.now().timestamp()
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license_plate = self._detect_license_plate(car)
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logger.debug(
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f"YOLOv9 LPD inference time: {(datetime.datetime.now().timestamp() - yolov9_start) * 1000:.2f} ms"
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)
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self.__update_yolov9_metrics(
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datetime.datetime.now().timestamp() - yolov9_start
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)
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if not license_plate:
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logger.debug("Detected no license plates for car object.")
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return
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if WRITE_DEBUG_IMAGES and license_plate:
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frame_with_rect = car.copy()
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cv2.rectangle(
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frame_with_rect,
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(
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int(license_plate[0]),
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int(license_plate[1]),
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),
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(
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int(license_plate[2]),
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int(license_plate[3]),
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),
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(0, 255, 0),
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2,
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)
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cv2.imwrite(
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f"debug/frames/car_frame_with_rect_{current_time}.jpg",
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frame_with_rect,
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)
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license_plate_area = max(
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0,
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(license_plate[2] - license_plate[0])
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* (license_plate[3] - license_plate[1]),
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)
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# check that license plate is valid
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# double the value because we've doubled the size of the car
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if (
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license_plate_area
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< self.config.cameras[obj_data["camera"]].lpr.min_area * 2
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):
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logger.debug("License plate is less than min_area")
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return
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license_plate_frame = car[
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license_plate[1] : license_plate[3],
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license_plate[0] : license_plate[2],
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]
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else:
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# don't run for object without attributes
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if not obj_data.get("current_attributes"):
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logger.debug("No attributes to parse.")
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return
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attributes: list[dict[str, any]] = obj_data.get(
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"current_attributes", []
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)
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for attr in attributes:
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if attr.get("label") != "license_plate":
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continue
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if license_plate is None or attr.get(
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"score", 0.0
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) > license_plate.get("score", 0.0):
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license_plate = attr
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# no license plates detected in this frame
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if not license_plate:
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return
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license_plate_box = license_plate.get("box")
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# check that license plate is valid
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if (
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not license_plate_box
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or area(license_plate_box)
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< self.config.cameras[obj_data["camera"]].lpr.min_area
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):
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logger.debug(f"Invalid license plate box {license_plate}")
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return
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license_plate_frame = cv2.cvtColor(frame, cv2.COLOR_YUV2BGR_I420)
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# Expand the license_plate_box by 30%
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box_array = np.array(license_plate_box)
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expansion = (box_array[2:] - box_array[:2]) * 0.30
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expanded_box = np.array(
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[
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license_plate_box[0] - expansion[0],
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license_plate_box[1] - expansion[1],
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license_plate_box[2] + expansion[0],
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license_plate_box[3] + expansion[1],
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]
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).clip(
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0, [license_plate_frame.shape[1], license_plate_frame.shape[0]] * 2
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)
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# Crop using the expanded box
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license_plate_frame = license_plate_frame[
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int(expanded_box[1]) : int(expanded_box[3]),
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int(expanded_box[0]) : int(expanded_box[2]),
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]
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# double the size of the license plate frame for better OCR
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license_plate_frame = cv2.resize(
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license_plate_frame,
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(
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int(2 * license_plate_frame.shape[1]),
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int(2 * license_plate_frame.shape[0]),
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),
|
||||
)
|
||||
|
||||
if WRITE_DEBUG_IMAGES:
|
||||
cv2.imwrite(
|
||||
f"debug/frames/license_plate_frame_{current_time}.jpg",
|
||||
license_plate_frame,
|
||||
)
|
||||
|
||||
start = datetime.datetime.now().timestamp()
|
||||
|
||||
# run detection, returns results sorted by confidence, best first
|
||||
@ -1027,6 +1183,47 @@ class LicensePlateProcessingMixin:
|
||||
else 0
|
||||
)
|
||||
|
||||
# Check against minimum confidence threshold
|
||||
if avg_confidence < self.lpr_config.recognition_threshold:
|
||||
logger.debug(
|
||||
f"Average confidence {avg_confidence} is less than threshold ({self.lpr_config.recognition_threshold})"
|
||||
)
|
||||
return
|
||||
|
||||
# For LPR cameras, match or assign plate ID using Jaro-Winkler distance
|
||||
if dedicated_lpr:
|
||||
plate_id = None
|
||||
# Similarity threshold for matching plates
|
||||
jaro_winkler_threshold = 0.8
|
||||
|
||||
for existing_id, data in self.detected_license_plates.items():
|
||||
if (
|
||||
data["camera"] == camera
|
||||
and data["last_seen"] is not None
|
||||
and current_time - data["last_seen"]
|
||||
<= self.config.cameras[camera].lpr.expire_time
|
||||
):
|
||||
similarity = jaro_winkler(data["plate"], top_plate)
|
||||
if similarity >= jaro_winkler_threshold:
|
||||
plate_id = existing_id
|
||||
logger.debug(
|
||||
f"Matched plate {top_plate} to {data['plate']} (similarity: {similarity:.3f})"
|
||||
)
|
||||
break
|
||||
if plate_id is None:
|
||||
# start new manual lpr event
|
||||
plate_id = self._generate_plate_event(obj_data, avg_confidence)
|
||||
logger.debug(
|
||||
f"New plate event for dedicated LPR camera {plate_id}: {top_plate}"
|
||||
)
|
||||
else:
|
||||
logger.debug(
|
||||
f"Matched existing plate event for dedicated LPR camera {plate_id}: {top_plate}"
|
||||
)
|
||||
self.detected_license_plates[plate_id]["last_seen"] = current_time
|
||||
|
||||
id = plate_id
|
||||
|
||||
# Check if we have a previously detected plate for this ID
|
||||
if id in self.detected_license_plates:
|
||||
if self._should_keep_previous_plate(
|
||||
@ -1035,13 +1232,6 @@ class LicensePlateProcessingMixin:
|
||||
logger.debug("Keeping previous plate")
|
||||
return
|
||||
|
||||
# Check against minimum confidence threshold
|
||||
if avg_confidence < self.lpr_config.recognition_threshold:
|
||||
logger.debug(
|
||||
f"Average confidence {avg_confidence} is less than threshold ({self.lpr_config.recognition_threshold})"
|
||||
)
|
||||
return
|
||||
|
||||
# Determine subLabel based on known plates, use regex matching
|
||||
# Default to the detected plate, use label name if there's a match
|
||||
sub_label = next(
|
||||
@ -1063,6 +1253,7 @@ class LicensePlateProcessingMixin:
|
||||
EventMetadataTypeEnum.sub_label, (id, sub_label, avg_confidence)
|
||||
)
|
||||
|
||||
logger.debug("publishing plate for", id, top_plate)
|
||||
self.sub_label_publisher.publish(
|
||||
EventMetadataTypeEnum.recognized_license_plate,
|
||||
(id, top_plate, avg_confidence),
|
||||
@ -1073,6 +1264,8 @@ class LicensePlateProcessingMixin:
|
||||
"char_confidences": top_char_confidences,
|
||||
"area": top_area,
|
||||
"obj_data": obj_data,
|
||||
"camera": camera,
|
||||
"last_seen": current_time if dedicated_lpr else None,
|
||||
}
|
||||
|
||||
def handle_request(self, topic, request_data) -> dict[str, any] | None:
|
||||
|
@ -35,9 +35,11 @@ class LicensePlateRealTimeProcessor(LicensePlateProcessingMixin, RealTimeProcess
|
||||
self.sub_label_publisher = sub_label_publisher
|
||||
super().__init__(config, metrics)
|
||||
|
||||
def process_frame(self, obj_data: dict[str, any], frame: np.ndarray):
|
||||
def process_frame(
|
||||
self, obj_data: dict[str, any], frame: np.ndarray, dedicated_lpr: bool = None
|
||||
):
|
||||
"""Look for license plates in image."""
|
||||
self.lpr_process(obj_data, frame)
|
||||
self.lpr_process(obj_data, frame, dedicated_lpr)
|
||||
|
||||
def handle_request(self, topic, request_data) -> dict[str, any] | None:
|
||||
return
|
||||
|
Loading…
Reference in New Issue
Block a user