tasks/image.py

from fastapi import APIRouter
from datetime import datetime
from datasets import load_dataset
import numpy as np
from sklearn.metrics import accuracy_score, precision_score, recall_score
import random
import os
from ultralytics import YOLO

from .utils.evaluation import ImageEvaluationRequest
from .utils.emissions import tracker, clean_emissions_data, get_space_info

from dotenv import load_dotenv
load_dotenv()

router = APIRouter()

MODEL_TYPE = "YOLOv11n"
DESCRIPTION = f"Simple {MODEL_TYPE} model"
ROUTE = "/image"

def parse_boxes(annotation_string):
    """Parse multiple boxes from a single annotation string.
    Each box has 5 values: class_id, x_center, y_center, width, height"""
    values = [float(x) for x in annotation_string.strip().split()]
    boxes = []
    # Each box has 5 values
    for i in range(0, len(values), 5):
        if i + 5 <= len(values):
            # Skip class_id (first value) and take the next 4 values
            box = values[i+1:i+5]
            boxes.append(box)
    return boxes

def compute_iou(box1, box2):
    """Compute Intersection over Union (IoU) between two YOLO format boxes."""
    # Convert YOLO format (x_center, y_center, width, height) to corners
    def yolo_to_corners(box):
        x_center, y_center, width, height = box
        x1 = x_center - width/2
        y1 = y_center - height/2
        x2 = x_center + width/2
        y2 = y_center + height/2
        return np.array([x1, y1, x2, y2])
    
    box1_corners = yolo_to_corners(box1)
    box2_corners = yolo_to_corners(box2)
    
    # Calculate intersection
    x1 = max(box1_corners[0], box2_corners[0])
    y1 = max(box1_corners[1], box2_corners[1])
    x2 = min(box1_corners[2], box2_corners[2])
    y2 = min(box1_corners[3], box2_corners[3])
    
    intersection = max(0, x2 - x1) * max(0, y2 - y1)
    
    # Calculate union
    box1_area = (box1_corners[2] - box1_corners[0]) * (box1_corners[3] - box1_corners[1])
    box2_area = (box2_corners[2] - box2_corners[0]) * (box2_corners[3] - box2_corners[1])
    union = box1_area + box2_area - intersection
    
    return intersection / (union + 1e-6)

def compute_max_iou(true_boxes, pred_box):
    """Compute maximum IoU between a predicted box and all true boxes"""
    max_iou = 0
    for true_box in true_boxes:
        iou = compute_iou(true_box, pred_box)
        max_iou = max(max_iou, iou)
    return max_iou

def load_model(path_to_model, model_type="YOLO"):
    if model_type == "YOLO":
        model = YOLO(path_to_model)
    else:
        raise NotImplementedError
    return model

def get_boxes_list(predictions):
    return [box.tolist() for box in predictions.boxes.xywhn]

@router.post(ROUTE, tags=["Image Task"],
             description=DESCRIPTION)
async def evaluate_image(request: ImageEvaluationRequest):
    """
    Evaluate image classification and object detection for forest fire smoke.
    
    Current Model: Random Baseline
    - Makes random predictions for both classification and bounding boxes
    - Used as a baseline for comparison
    
    Metrics:
    - Classification accuracy: Whether an image contains smoke or not
    - Object Detection accuracy: IoU (Intersection over Union) for smoke bounding boxes
    """
    # Get space info
    username, space_url = get_space_info()
    
    # Load and prepare the dataset
    dataset = load_dataset(request.dataset_name, token=os.getenv("HF_TOKEN"))
    
    # Split dataset
    train_test = dataset["train"].train_test_split(test_size=request.test_size, seed=request.test_seed)
    test_dataset = train_test["test"]
    
    # Start tracking emissions
    tracker.start()
    tracker.start_task("inference")
    
    #--------------------------------------------------------------------------------------------
    # YOUR MODEL INFERENCE CODE HERE
    # Update the code below to replace the random baseline with your model inference
    #--------------------------------------------------------------------------------------------   
    
    
    PATH_TO_MODEL = f"models/best_{MODEL_TYPE}.pt"
    model = load_model(PATH_TO_MODEL)
    
    print(f"Model info: {model.info()}")
    predictions = []
    true_labels = []
    pred_boxes = []
    true_boxes_list = []  # List of lists, each inner list contains boxes for one image
    
    n_examples = len(test_dataset)
    for i, example in enumerate(test_dataset):
        print(f"Running {i+1} of {n_examples}")
        # Parse true annotation (YOLO format: class_id x_center y_center width height)
        annotation = example.get("annotations", "").strip()
        has_smoke = len(annotation) > 0
        true_labels.append(int(has_smoke))
        
        model_preds = model(example['image'])[0]
        pred_has_smoke = len(model_preds) > 0
        predictions.append(int(pred_has_smoke))
        
        # If there's a true box, parse it and make random box prediction
        if has_smoke:
            
            # Parse all true boxes from the annotation
            image_true_boxes = parse_boxes(annotation)
            true_boxes_list.append(image_true_boxes)
            
            try:
                pred_box_list = get_boxes_list(model_preds)[0] # With one bbox to start with (as in the random baseline)
            except:
                print("No boxes found")
                pred_box_list = [0, 0, 0, 0] # Hacky way to make sure that compute_max_iou doesn't fail
            pred_boxes.append(pred_box_list)


    
    #--------------------------------------------------------------------------------------------
    # YOUR MODEL INFERENCE STOPS HERE
    #--------------------------------------------------------------------------------------------   
    
    # Stop tracking emissions
    emissions_data = tracker.stop_task()
    
    # Calculate classification metrics
    classification_accuracy = accuracy_score(true_labels, predictions)
    classification_precision = precision_score(true_labels, predictions)
    classification_recall = recall_score(true_labels, predictions)
    
    # Calculate mean IoU for object detection (only for images with smoke)
    # For each image, we compute the max IoU between the predicted box and all true boxes
    ious = []
    for true_boxes, pred_box in zip(true_boxes_list, pred_boxes):
        max_iou = compute_max_iou(true_boxes, pred_box)
        ious.append(max_iou)
    
    mean_iou = float(np.mean(ious)) if ious else 0.0
    
    # Prepare results dictionary
    results = {
        "username": username,
        "space_url": space_url,
        "submission_timestamp": datetime.now().isoformat(),
        "model_description": DESCRIPTION,
        "classification_accuracy": float(classification_accuracy),
        "classification_precision": float(classification_precision),
        "classification_recall": float(classification_recall),
        "mean_iou": mean_iou,
        "energy_consumed_wh": emissions_data.energy_consumed * 1000,
        "emissions_gco2eq": emissions_data.emissions * 1000,
        "emissions_data": clean_emissions_data(emissions_data),
        "api_route": ROUTE,
        "dataset_config": {
            "dataset_name": request.dataset_name,
            "test_size": request.test_size,
            "test_seed": request.test_seed
        }
    }
    
    return results