added simple inference script for binary classifier

.gitignore

@@ -18,4 +18,7 @@ data/
 
 # Misc
 .DS_Store
-checkpoints/
+
+checkpoints/
+results/
+checkpoints/

src/common/binary_classifier_inference.py

@@ -0,0 +1,281 @@
+import math
+import os
+import xml.etree.ElementTree as ET
+from glob import glob
+from typing import Generator
+
+import torch
+from binary_classifier import BinaryClassifier
+from PIL import Image, ImageDraw
+from torchvision import transforms
+
+FOLDER = "data/VOC2012/VOC2012_test/JPEGImages"
+MODEL_PATH = "checkpoints/best_model.pth"
+THRESHOLD = 0.9
+OUTPUT_PATH = "results/collage.jpg"
+WINDOW_SIZES = [256, 512]
+STRIDE_RATIO = 0.5
+NMS_IOU_THRESHOLD = 0.2
+ANNOTATION_DIR = "data/VOC2012/VOC2012_test/Annotations"
+TARGET_CLASSES = {"person", "cat"}
+
+
+def get_transform() -> transforms.Compose:
+    return transforms.Compose(
+        [
+            transforms.Resize((64, 64)),
+            transforms.ToTensor(),
+            transforms.Normalize(mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225]),
+        ]
+    )
+
+
+def sliding_window(
+    image_width: int, image_height: int, window_size: int, stride: int
+) -> Generator[tuple[int, int, int, int], None, None]:
+    """Generate sliding window coordinates."""
+    for y in range(0, image_height - window_size + 1, stride):
+        for x in range(0, image_width - window_size + 1, stride):
+            yield (x, y, x + window_size, y + window_size)
+
+    # Handle right edge
+    if (image_width - window_size) % stride != 0:
+        for y in range(0, image_height - window_size + 1, stride):
+            x = image_width - window_size
+            yield (x, y, x + window_size, y + window_size)
+
+    # Handle bottom edge
+    if (image_height - window_size) % stride != 0:
+        for x in range(0, image_width - window_size + 1, stride):
+            y = image_height - window_size
+            yield (x, y, x + window_size, y + window_size)
+
+    # Handle bottom-right corner
+    if (image_width - window_size) % stride != 0 and (
+        image_height - window_size
+    ) % stride != 0:
+        yield (
+            image_width - window_size,
+            image_height - window_size,
+            image_width,
+            image_height,
+        )
+
+
+def compute_iou(
+    box1: tuple[int, int, int, int], box2: tuple[int, int, int, int]
+) -> float:
+    """Compute IoU between two boxes (x1, y1, x2, y2)."""
+    x1 = max(box1[0], box2[0])
+    y1 = max(box1[1], box2[1])
+    x2 = min(box1[2], box2[2])
+    y2 = min(box1[3], box2[3])
+
+    intersection = max(0, x2 - x1) * max(0, y2 - y1)
+    area1 = (box1[2] - box1[0]) * (box1[3] - box1[1])
+    area2 = (box2[2] - box2[0]) * (box2[3] - box2[1])
+    union = area1 + area2 - intersection
+
+    return intersection / union if union > 0 else 0
+
+
+def non_max_suppression(
+    detections: list[tuple[tuple[int, int, int, int], float]], iou_threshold: float
+) -> list[tuple[tuple[int, int, int, int], float]]:
+    """Apply NMS to detections. Each detection is (box, confidence)."""
+    if not detections:
+        return []
+
+    # Sort by confidence (descending)
+    detections = sorted(detections, key=lambda x: x[1], reverse=True)
+
+    keep = []
+    while detections:
+        best = detections.pop(0)
+        keep.append(best)
+
+        detections = [
+            d for d in detections if compute_iou(best[0], d[0]) < iou_threshold
+        ]
+
+    return keep
+
+
+def detect_in_image(
+    image: Image.Image,
+    model: BinaryClassifier,
+    transform: transforms.Compose,
+    device: torch.device,
+) -> list[tuple[tuple[int, int, int, int], float]]:
+    """Run sliding window detection on a single image."""
+    width, height = image.size
+    all_detections = []
+
+    for window_size in WINDOW_SIZES:
+        if width < window_size or height < window_size:
+            continue
+
+        stride = int(window_size * STRIDE_RATIO)
+
+        # Collect all windows for this scale
+        windows = list(sliding_window(width, height, window_size, stride))
+        crops = []
+        coords = []
+
+        for x1, y1, x2, y2 in windows:
+            crop = image.crop((x1, y1, x2, y2))
+            crops.append(transform(crop))
+            coords.append((x1, y1, x2, y2))
+
+        # Batch inference
+        BATCH_SIZE = 64
+        for batch_start in range(0, len(crops), BATCH_SIZE):
+            batch_end = min(batch_start + BATCH_SIZE, len(crops))
+            batch_tensor = torch.stack(crops[batch_start:batch_end]).to(device)
+
+            with torch.no_grad():
+                outputs = model(batch_tensor)
+                confidences = torch.sigmoid(outputs).squeeze(-1)
+
+            for j, conf in enumerate(confidences):
+                if conf.item() >= THRESHOLD:
+                    all_detections.append((coords[batch_start + j], conf.item()))
+
+    detections = non_max_suppression(all_detections, NMS_IOU_THRESHOLD)
+    return detections
+
+
+def get_valid_image_ids() -> set[str]:
+    """Get image IDs that contain target classes."""
+    valid_ids = set()
+
+    for xml_file in os.listdir(ANNOTATION_DIR):
+        if not xml_file.endswith(".xml"):
+            continue
+
+        tree = ET.parse(os.path.join(ANNOTATION_DIR, xml_file))
+        root = tree.getroot()
+
+        classes_in_image = set()
+        for obj in root.findall("object"):
+            name = obj.find("name")
+            if name is not None and name.text:
+                classes_in_image.add(name.text)
+
+        if classes_in_image & TARGET_CLASSES:
+            image_id = xml_file.replace(".xml", "")
+            valid_ids.add(image_id)
+
+    return valid_ids
+
+
+def run_inference() -> None:
+    os.makedirs(os.path.dirname(OUTPUT_PATH), exist_ok=True)
+
+    if torch.cuda.is_available():
+        device = torch.device("cuda")
+    elif torch.backends.mps.is_available():
+        device = torch.device("mps")
+    else:
+        device = torch.device("cpu")
+    print(f"Using device: {device}")
+
+    model = BinaryClassifier(device=str(device))
+    model.load_state_dict(torch.load(MODEL_PATH, map_location=device))
+    model.eval()
+
+    transform = get_transform()
+
+    extensions = ["*.jpg", "*.jpeg", "*.png", "*.bmp", "*.webp"]
+    image_paths = []
+    for ext in extensions:
+        image_paths.extend(glob(os.path.join(FOLDER, ext)))
+        image_paths.extend(glob(os.path.join(FOLDER, ext.upper())))
+
+    print(f"Found {len(image_paths)} images")
+
+    # Filter to only images with target classes
+    valid_ids = get_valid_image_ids()
+    image_paths = [
+        p for p in image_paths if os.path.splitext(os.path.basename(p))[0] in valid_ids
+    ]
+    print(f"Filtered to {len(image_paths)} images containing {TARGET_CLASSES}")
+
+    results = []  # (path, image_with_boxes, num_detections, max_confidence)
+
+    for i, path in enumerate(image_paths):
+        img = Image.open(path).convert("RGB")
+        detections = detect_in_image(img, model, transform, device)
+
+        if detections:
+            # Draw bounding boxes on image
+            img_with_boxes = img.copy()
+            draw = ImageDraw.Draw(img_with_boxes)
+
+            max_conf = 0.0
+            for box, conf in detections:
+                draw.rectangle(box, outline="red", width=3)
+                draw.text((box[0], box[1] - 15), f"{conf:.2f}", fill="red")
+                max_conf = max(max_conf, conf)
+
+            results.append((path, img_with_boxes, len(detections), max_conf))
+            print(
+                f"✓ {os.path.basename(path)}: {len(detections)} detections (max conf: {max_conf:.3f})"
+            )
+
+        if (i + 1) % 50 == 0:
+            print(f"Processed {i + 1}/{len(image_paths)} images...")
+
+    print(f"\n{len(results)} images with detections")
+
+    if not results:
+        print("No detections found.")
+        return
+
+    # Sort by max confidence
+    results.sort(key=lambda x: x[3], reverse=True)
+
+    # Create collage with bounding boxes
+    GRID_SIZE = 5
+    THUMB_SIZE = 200
+    PAGE_SIZE = GRID_SIZE * THUMB_SIZE
+
+    num_pages = math.ceil(len(results) / 25)
+
+    for page_idx in range(num_pages):
+        collage = Image.new("RGB", (PAGE_SIZE, PAGE_SIZE), (255, 255, 255))
+        start = page_idx * 25
+        end = min(start + 25, len(results))
+
+        for i, (path, img_with_boxes, num_det, max_conf) in enumerate(
+            results[start:end]
+        ):
+            thumb = img_with_boxes.copy()
+            thumb.thumbnail((THUMB_SIZE, THUMB_SIZE - 20))
+
+            cell = Image.new("RGB", (THUMB_SIZE, THUMB_SIZE), (255, 255, 255))
+            x_offset = (THUMB_SIZE - thumb.width) // 2
+            cell.paste(thumb, (x_offset, 0))
+
+            # Add text showing detections and confidence
+            draw = ImageDraw.Draw(cell)
+            text = f"{num_det} det | {max_conf:.2f}"
+            bbox = draw.textbbox((0, 0), text)
+            text_x = (THUMB_SIZE - (bbox[2] - bbox[0])) // 2
+            draw.text((text_x, THUMB_SIZE - 16), text, fill=(255, 0, 0))
+
+            row, col = divmod(i, GRID_SIZE)
+            collage.paste(cell, (col * THUMB_SIZE, row * THUMB_SIZE))
+
+        if num_pages == 1:
+            save_path = OUTPUT_PATH
+        else:
+            base, ext = os.path.splitext(OUTPUT_PATH)
+            save_path = f"{base}_page{page_idx + 1}{ext}"
+
+        collage.save(save_path)
+        print(f"Saved collage: {save_path}")
+
+
+if __name__ == "__main__":
+    run_inference()