dev(MeanAP): add MeanAP

mmeval/detection/__init__.py

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+# Copyright (c) OpenMMLab. All rights reserved.
+
+# flake8: noqa
+
+from voc_map import VOCMeanAP
+
+from .utils import *
+
+__all__ = ['VOCMeanAP']

mmeval/detection/utils/__init__.py

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+# Copyright (c) OpenMMLab. All rights reserved.
+
+from .bbox import calculate_bboxes_area, calculate_overlaps
+
+__all__ = [
+    'calculate_bboxes_area',
+    'calculate_overlaps',
+]

mmeval/detection/utils/bbox.py

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+# Copyright (c) OpenMMLab. All rights reserved.
+
+import numpy as np
+
+
+def calculate_bboxes_area(bboxes: np.ndarray,
+                          use_legacy_coordinate: bool = False):
+    """Calculate area of bounding boxes.
+
+    Args:
+        bboxes (numpy.ndarray): The bboxes with shape (..., 4) in 'xyxy' format.  # noqa: E501
+        use_legacy_coordinate (bool): Whether to use coordinate system in
+            mmdet v1.x. which means width, height should be
+            calculated as 'x2 - x1 + 1` and 'y2 - y1 + 1' respectively.
+            Note when function is used in `VOCDataset`, it should be
+            True to align with the official implementation
+            `http://host.robots.ox.ac.uk/pascal/VOC/voc2012/VOCdevkit_18-May-2011.tar`
+            Default: False.
+
+     Returns:
+        numpy.ndarray: The area of bboxes.
+    """
+    if use_legacy_coordinate:
+        extra_length = 1.
+    else:
+        extra_length = 0.
+    bboxes_w = (bboxes[..., 2] - bboxes[..., 0] + extra_length)
+    bboxes_h = (bboxes[..., 3] - bboxes[..., 1] + extra_length)
+    areas = bboxes_w * bboxes_h
+    return areas
+
+
+def calculate_overlaps(bboxes1,
+                       bboxes2,
+                       mode='iou',
+                       eps=1e-6,
+                       use_legacy_coordinate=False):
+    """Calculate the overlap between each bbox of bboxes1 and bboxes2.
+
+    Args:
+        bboxes1 (ndarray): Shape (n, 4)
+        bboxes2 (ndarray): Shape (k, 4)
+        mode (str): 'iou' (intersection over union) or 'iof' (intersection
+            over foreground)
+        eps (float): The epsilon value.
+        use_legacy_coordinate (bool): Whether to use coordinate system in
+            mmdet v1.x. which means width, height should be
+            calculated as 'x2 - x1 + 1` and 'y2 - y1 + 1' respectively.
+            Note when function is used in `VOCDataset`, it should be
+            True to align with the official implementation
+            `http://host.robots.ox.ac.uk/pascal/VOC/voc2012/VOCdevkit_18-May-2011.tar`
+            Default: False.
+
+    Returns:
+        numpy.ndarray: IoUs or IoFs with shape (n, k).
+    """
+    assert mode in ['iou', 'iof']
+    bboxes1 = bboxes1.astype(np.float32)
+    bboxes2 = bboxes2.astype(np.float32)
+    rows = bboxes1.shape[0]
+    cols = bboxes2.shape[0]
+    overlaps = np.zeros((rows, cols), dtype=np.float32)
+
+    if rows * cols == 0:
+        return overlaps
+
+    if bboxes1.shape[0] > bboxes2.shape[0]:
+        # Swap bboxes for faster calculation.
+        return calculate_overlaps(
+            bboxes2,
+            bboxes1,
+            mode=mode,
+            eps=eps,
+            use_legacy_coordinate=use_legacy_coordinate)
+
+    area1 = calculate_bboxes_area(bboxes1, use_legacy_coordinate)
+    area2 = calculate_bboxes_area(bboxes2, use_legacy_coordinate)
+
+    if use_legacy_coordinate:
+        extra_length = 1.
+    else:
+        extra_length = 0.
+
+    for i in range(bboxes1.shape[0]):
+        x_start = np.maximum(bboxes1[i, 0], bboxes2[:, 0])
+        y_start = np.maximum(bboxes1[i, 1], bboxes2[:, 1])
+        x_end = np.minimum(bboxes1[i, 2], bboxes2[:, 2])
+        y_end = np.minimum(bboxes1[i, 3], bboxes2[:, 3])
+        overlap_w = np.maximum(x_end - x_start + extra_length, 0)
+        overlap_h = np.maximum(y_end - y_start + extra_length, 0)
+        overlap = overlap_w * overlap_h
+
+        if mode == 'iou':
+            union = area1[i] + area2 - overlap
+        else:
+            union = area1[i]
+
+        union = np.maximum(union, eps)
+        overlaps[i, :] = overlap / union
+    return overlaps