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on
Zero
Running
on
Zero
import os | |
import logging | |
import random | |
from PIL import Image, ImageDraw, ImageFont | |
from huggingface_hub import hf_hub_download | |
logger = logging.getLogger(__name__) | |
class ObjectDetector: | |
def __init__(self, model_key="yolov8n", device="cpu"): | |
self.device = device | |
self.model = None | |
self.model_key = model_key.lower().replace(".pt", "") | |
hf_map = { | |
"yolov8n": ("ultralytics/yolov8", "yolov8n.pt"), | |
"yolov8s": ("ultralytics/yolov8", "yolov8s.pt"), | |
"yolov8l": ("ultralytics/yolov8", "yolov8l.pt"), | |
"yolov11b": ("Ultralytics/YOLO11", "yolov11b.pt"), | |
} | |
if self.model_key not in hf_map: | |
raise ValueError(f"Unsupported model key: {self.model_key}") | |
repo_id, filename = hf_map[self.model_key] | |
self.weights_path = hf_hub_download( | |
repo_id=repo_id, | |
filename=filename, | |
cache_dir="models/detection/weights", | |
force_download=False | |
) | |
def load_model(self): | |
logger.info(f"Loading model from path: {self.weights_path}") | |
if self.model is None: | |
import torch # Safe to import here | |
from ultralytics import YOLO # Defer import | |
if self.device == "cpu": | |
os.environ["CUDA_VISIBLE_DEVICES"] = "-1" | |
# Initialize model | |
self.model = YOLO(self.weights_path) | |
# Move to CUDA only if necessary and safe | |
if self.device == "cuda" and torch.cuda.is_available(): | |
self.model.to("cuda") | |
return self | |
def predict(self, image: Image.Image, conf_threshold=0.25): | |
self.load_model() | |
if self.model is None: | |
raise RuntimeError("YOLO model not loaded. Call load_model() first.") | |
results = self.model(image) | |
detections = [] | |
for r in results: | |
for box in r.boxes: | |
detections.append({ | |
"class_name": r.names[int(box.cls)], | |
"confidence": float(box.conf), | |
"bbox": box.xyxy[0].tolist() | |
}) | |
return detections | |
def draw(self, image: Image.Image, detections, alpha=0.5): | |
""" | |
Draws thicker, per-class-colored bounding boxes and labels. | |
Args: | |
image (PIL.Image.Image): Original image. | |
detections (List[Dict]): Each dict has "bbox", "class_name", "confidence". | |
alpha (float): Blend strength for overlay. | |
Returns: | |
PIL.Image.Image: Blended image with overlays. | |
""" | |
# copy & overlay | |
overlay = image.copy() | |
draw = ImageDraw.Draw(overlay) | |
# try a TTF font, fallback to default | |
try: | |
font = ImageFont.truetype("arial.ttf", 18) | |
except: | |
font = ImageFont.load_default() | |
# deterministic color per class | |
class_colors = {} | |
def get_color(cls): | |
if cls not in class_colors: | |
# seed by class name → same color every run | |
rnd = random.Random(cls) | |
class_colors[cls] = ( | |
rnd.randint(100, 255), | |
rnd.randint(100, 255), | |
rnd.randint(100, 255), | |
) | |
return class_colors[cls] | |
for det in detections: | |
x1, y1, x2, y2 = det["bbox"] | |
cls_name = det["class_name"] | |
conf = det["confidence"] | |
label = f"{cls_name} {conf:.2f}" | |
color = get_color(cls_name) | |
# thicker box: draw multiple offsets | |
for t in range(4): | |
draw.rectangle( | |
(x1 - t, y1 - t, x2 + t, y2 + t), | |
outline=color | |
) | |
# calculate text size | |
text_box = draw.textbbox((x1, y1), label, font=font) | |
tb_w = text_box[2] - text_box[0] | |
tb_h = text_box[3] - text_box[1] | |
# background rect for text | |
bg = (x1, y1 - tb_h, x1 + tb_w + 6, y1) | |
draw.rectangle(bg, fill=color) | |
# draw text (with small padding) | |
draw.text((x1 + 3, y1 - tb_h), label, font=font, fill="black") | |
# blend and return | |
return Image.blend(image, overlay, alpha) |