Files
supervision/supervision/detection/utils.py
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809 lines
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Python

from itertools import chain
from typing import Any, Dict, List, Optional, Tuple, Union
import cv2
import numpy as np
from supervision.config import CLASS_NAME_DATA_FIELD
MIN_POLYGON_POINT_COUNT = 3
def polygon_to_mask(polygon: np.ndarray, resolution_wh: Tuple[int, int]) -> np.ndarray:
"""Generate a mask from a polygon.
Args:
polygon (np.ndarray): The polygon for which the mask should be generated,
given as a list of vertices.
resolution_wh (Tuple[int, int]): The width and height of the desired resolution.
Returns:
np.ndarray: The generated 2D mask, where the polygon is marked with
`1`'s and the rest is filled with `0`'s.
"""
width, height = resolution_wh
mask = np.zeros((height, width))
cv2.fillPoly(mask, [polygon], color=1)
return mask
def box_iou_batch(boxes_true: np.ndarray, boxes_detection: np.ndarray) -> np.ndarray:
"""
Compute Intersection over Union (IoU) of two sets of bounding boxes -
`boxes_true` and `boxes_detection`. Both sets
of boxes are expected to be in `(x_min, y_min, x_max, y_max)` format.
Args:
boxes_true (np.ndarray): 2D `np.ndarray` representing ground-truth boxes.
`shape = (N, 4)` where `N` is number of true objects.
boxes_detection (np.ndarray): 2D `np.ndarray` representing detection boxes.
`shape = (M, 4)` where `M` is number of detected objects.
Returns:
np.ndarray: Pairwise IoU of boxes from `boxes_true` and `boxes_detection`.
`shape = (N, M)` where `N` is number of true objects and
`M` is number of detected objects.
"""
def box_area(box):
return (box[2] - box[0]) * (box[3] - box[1])
area_true = box_area(boxes_true.T)
area_detection = box_area(boxes_detection.T)
top_left = np.maximum(boxes_true[:, None, :2], boxes_detection[:, :2])
bottom_right = np.minimum(boxes_true[:, None, 2:], boxes_detection[:, 2:])
area_inter = np.prod(np.clip(bottom_right - top_left, a_min=0, a_max=None), 2)
return area_inter / (area_true[:, None] + area_detection - area_inter)
def mask_iou_batch(masks_true: np.ndarray, masks_detection: np.ndarray) -> np.ndarray:
"""
Compute Intersection over Union (IoU) of two sets of masks -
`masks_true` and `masks_detection`.
Args:
masks_true (np.ndarray): 3D `np.ndarray` representing ground-truth masks.
masks_detection (np.ndarray): 3D `np.ndarray` representing detection masks.
Returns:
np.ndarray: Pairwise IoU of masks from `masks_true` and `masks_detection`.
"""
intersection_area = np.logical_and(masks_true[:, None], masks_detection).sum(
axis=(2, 3)
)
masks_true_area = masks_true.sum(axis=(1, 2))
masks_detection_area = masks_detection.sum(axis=(1, 2))
union_area = masks_true_area[:, None] + masks_detection_area - intersection_area
return np.divide(
intersection_area,
union_area,
out=np.zeros_like(intersection_area, dtype=float),
where=union_area != 0,
)
def resize_masks(masks: np.ndarray, max_dimension: int = 640) -> np.ndarray:
"""
Resize all masks in the array to have a maximum dimension of max_dimension,
maintaining aspect ratio.
Args:
masks (np.ndarray): 3D array of binary masks with shape (N, H, W).
max_dimension (int): The maximum dimension for the resized masks.
Returns:
np.ndarray: Array of resized masks.
"""
max_height = np.max(masks.shape[1])
max_width = np.max(masks.shape[2])
scale = min(max_dimension / max_height, max_dimension / max_width)
new_height = int(scale * max_height)
new_width = int(scale * max_width)
x = np.linspace(0, max_width - 1, new_width).astype(int)
y = np.linspace(0, max_height - 1, new_height).astype(int)
xv, yv = np.meshgrid(x, y)
resized_masks = masks[:, yv, xv]
resized_masks = resized_masks.reshape(masks.shape[0], new_height, new_width)
return resized_masks
def mask_non_max_suppression(
predictions: np.ndarray,
masks: np.ndarray,
iou_threshold: float = 0.5,
mask_dimension: int = 640,
) -> np.ndarray:
"""
Perform Non-Maximum Suppression (NMS) on segmentation predictions.
Args:
predictions (np.ndarray): A 2D array of object detection predictions in
the format of `(x_min, y_min, x_max, y_max, score)`
or `(x_min, y_min, x_max, y_max, score, class)`. Shape: `(N, 5)` or
`(N, 6)`, where N is the number of predictions.
masks (np.ndarray): A 3D array of binary masks corresponding to the predictions.
Shape: `(N, H, W)`, where N is the number of predictions, and H, W are the
dimensions of each mask.
iou_threshold (float, optional): The intersection-over-union threshold
to use for non-maximum suppression.
mask_dimension (int, optional): The dimension to which the masks should be
resized before computing IOU values. Defaults to 640.
Returns:
np.ndarray: A boolean array indicating which predictions to keep after
non-maximum suppression.
Raises:
AssertionError: If `iou_threshold` is not within the closed
range from `0` to `1`.
"""
assert 0 <= iou_threshold <= 1, (
"Value of `iou_threshold` must be in the closed range from 0 to 1, "
f"{iou_threshold} given."
)
rows, columns = predictions.shape
if columns == 5:
predictions = np.c_[predictions, np.zeros(rows)]
sort_index = predictions[:, 4].argsort()[::-1]
predictions = predictions[sort_index]
masks = masks[sort_index]
masks_resized = resize_masks(masks, mask_dimension)
ious = mask_iou_batch(masks_resized, masks_resized)
categories = predictions[:, 5]
keep = np.ones(rows, dtype=bool)
for i in range(rows):
if keep[i]:
condition = (ious[i] > iou_threshold) & (categories[i] == categories)
keep[i + 1 :] = np.where(condition[i + 1 :], False, keep[i + 1 :])
return keep
def box_non_max_suppression(
predictions: np.ndarray, iou_threshold: float = 0.5
) -> np.ndarray:
"""
Perform Non-Maximum Suppression (NMS) on object detection predictions.
Args:
predictions (np.ndarray): An array of object detection predictions in
the format of `(x_min, y_min, x_max, y_max, score)`
or `(x_min, y_min, x_max, y_max, score, class)`.
iou_threshold (float, optional): The intersection-over-union threshold
to use for non-maximum suppression.
Returns:
np.ndarray: A boolean array indicating which predictions to keep after n
on-maximum suppression.
Raises:
AssertionError: If `iou_threshold` is not within the
closed range from `0` to `1`.
"""
assert 0 <= iou_threshold <= 1, (
"Value of `iou_threshold` must be in the closed range from 0 to 1, "
f"{iou_threshold} given."
)
rows, columns = predictions.shape
# add column #5 - category filled with zeros for agnostic nms
if columns == 5:
predictions = np.c_[predictions, np.zeros(rows)]
# sort predictions column #4 - score
sort_index = np.flip(predictions[:, 4].argsort())
predictions = predictions[sort_index]
boxes = predictions[:, :4]
categories = predictions[:, 5]
ious = box_iou_batch(boxes, boxes)
ious = ious - np.eye(rows)
keep = np.ones(rows, dtype=bool)
for index, (iou, category) in enumerate(zip(ious, categories)):
if not keep[index]:
continue
# drop detections with iou > iou_threshold and
# same category as current detections
condition = (iou > iou_threshold) & (categories == category)
keep = keep & ~condition
return keep[sort_index.argsort()]
def clip_boxes(xyxy: np.ndarray, resolution_wh: Tuple[int, int]) -> np.ndarray:
"""
Clips bounding boxes coordinates to fit within the frame resolution.
Args:
xyxy (np.ndarray): A numpy array of shape `(N, 4)` where each
row corresponds to a bounding box in
the format `(x_min, y_min, x_max, y_max)`.
resolution_wh (Tuple[int, int]): A tuple of the form `(width, height)`
representing the resolution of the frame.
Returns:
np.ndarray: A numpy array of shape `(N, 4)` where each row
corresponds to a bounding box with coordinates clipped to fit
within the frame resolution.
"""
result = np.copy(xyxy)
width, height = resolution_wh
result[:, [0, 2]] = result[:, [0, 2]].clip(0, width)
result[:, [1, 3]] = result[:, [1, 3]].clip(0, height)
return result
def xywh_to_xyxy(boxes_xywh: np.ndarray) -> np.ndarray:
xyxy = boxes_xywh.copy()
xyxy[:, 2] = boxes_xywh[:, 0] + boxes_xywh[:, 2]
xyxy[:, 3] = boxes_xywh[:, 1] + boxes_xywh[:, 3]
return xyxy
def mask_to_xyxy(masks: np.ndarray) -> np.ndarray:
"""
Converts a 3D `np.array` of 2D bool masks into a 2D `np.array` of bounding boxes.
Parameters:
masks (np.ndarray): A 3D `np.array` of shape `(N, W, H)`
containing 2D bool masks
Returns:
np.ndarray: A 2D `np.array` of shape `(N, 4)` containing the bounding boxes
`(x_min, y_min, x_max, y_max)` for each mask
"""
n = masks.shape[0]
bboxes = np.zeros((n, 4), dtype=int)
for i, mask in enumerate(masks):
rows, cols = np.where(mask)
if len(rows) > 0 and len(cols) > 0:
x_min, x_max = np.min(cols), np.max(cols)
y_min, y_max = np.min(rows), np.max(rows)
bboxes[i, :] = [x_min, y_min, x_max, y_max]
return bboxes
def mask_to_polygons(mask: np.ndarray) -> List[np.ndarray]:
"""
Converts a binary mask to a list of polygons.
Parameters:
mask (np.ndarray): A binary mask represented as a 2D NumPy array of
shape `(H, W)`, where H and W are the height and width of
the mask, respectively.
Returns:
List[np.ndarray]: A list of polygons, where each polygon is represented by a
NumPy array of shape `(N, 2)`, containing the `x`, `y` coordinates
of the points. Polygons with fewer points than `MIN_POLYGON_POINT_COUNT = 3`
are excluded from the output.
"""
contours, _ = cv2.findContours(
mask.astype(np.uint8), cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE
)
return [
np.squeeze(contour, axis=1)
for contour in contours
if contour.shape[0] >= MIN_POLYGON_POINT_COUNT
]
def filter_polygons_by_area(
polygons: List[np.ndarray],
min_area: Optional[float] = None,
max_area: Optional[float] = None,
) -> List[np.ndarray]:
"""
Filters a list of polygons based on their area.
Parameters:
polygons (List[np.ndarray]): A list of polygons, where each polygon is
represented by a NumPy array of shape `(N, 2)`,
containing the `x`, `y` coordinates of the points.
min_area (Optional[float]): The minimum area threshold.
Only polygons with an area greater than or equal to this value
will be included in the output. If set to None,
no minimum area constraint will be applied.
max_area (Optional[float]): The maximum area threshold.
Only polygons with an area less than or equal to this value
will be included in the output. If set to None,
no maximum area constraint will be applied.
Returns:
List[np.ndarray]: A new list of polygons containing only those with
areas within the specified thresholds.
"""
if min_area is None and max_area is None:
return polygons
ares = [cv2.contourArea(polygon) for polygon in polygons]
return [
polygon
for polygon, area in zip(polygons, ares)
if (min_area is None or area >= min_area)
and (max_area is None or area <= max_area)
]
def polygon_to_xyxy(polygon: np.ndarray) -> np.ndarray:
"""
Converts a polygon represented by a NumPy array into a bounding box.
Parameters:
polygon (np.ndarray): A polygon represented by a NumPy array of shape `(N, 2)`,
containing the `x`, `y` coordinates of the points.
Returns:
np.ndarray: A 1D NumPy array containing the bounding box
`(x_min, y_min, x_max, y_max)` of the input polygon.
"""
x_min, y_min = np.min(polygon, axis=0)
x_max, y_max = np.max(polygon, axis=0)
return np.array([x_min, y_min, x_max, y_max])
def approximate_polygon(
polygon: np.ndarray, percentage: float, epsilon_step: float = 0.05
) -> np.ndarray:
"""
Approximates a given polygon by reducing a certain percentage of points.
This function uses the Ramer-Douglas-Peucker algorithm to simplify the input
polygon by reducing the number of points
while preserving the general shape.
Parameters:
polygon (np.ndarray): A 2D NumPy array of shape `(N, 2)` containing
the `x`, `y` coordinates of the input polygon's points.
percentage (float): The percentage of points to be removed from the
input polygon, in the range `[0, 1)`.
epsilon_step (float): Approximation accuracy step.
Epsilon is the maximum distance between the original curve
and its approximation.
Returns:
np.ndarray: A new 2D NumPy array of shape `(M, 2)`,
where `M <= N * (1 - percentage)`, containing
the `x`, `y` coordinates of the
approximated polygon's points.
"""
if percentage < 0 or percentage >= 1:
raise ValueError("Percentage must be in the range [0, 1).")
target_points = max(int(len(polygon) * (1 - percentage)), 3)
if len(polygon) <= target_points:
return polygon
epsilon = 0
approximated_points = polygon
while True:
epsilon += epsilon_step
new_approximated_points = cv2.approxPolyDP(polygon, epsilon, closed=True)
if len(new_approximated_points) > target_points:
approximated_points = new_approximated_points
else:
break
return np.squeeze(approximated_points, axis=1)
def extract_ultralytics_masks(yolov8_results) -> Optional[np.ndarray]:
if not yolov8_results.masks:
return None
orig_shape = yolov8_results.orig_shape
inference_shape = tuple(yolov8_results.masks.data.shape[1:])
pad = (0, 0)
if inference_shape != orig_shape:
gain = min(
inference_shape[0] / orig_shape[0],
inference_shape[1] / orig_shape[1],
)
pad = (
(inference_shape[1] - orig_shape[1] * gain) / 2,
(inference_shape[0] - orig_shape[0] * gain) / 2,
)
top, left = int(pad[1]), int(pad[0])
bottom, right = int(inference_shape[0] - pad[1]), int(inference_shape[1] - pad[0])
mask_maps = []
masks = yolov8_results.masks.data.cpu().numpy()
for i in range(masks.shape[0]):
mask = masks[i]
mask = mask[top:bottom, left:right]
if mask.shape != orig_shape:
mask = cv2.resize(mask, (orig_shape[1], orig_shape[0]))
mask_maps.append(mask)
return np.asarray(mask_maps, dtype=bool)
def process_roboflow_result(
roboflow_result: dict,
) -> Tuple[
np.ndarray,
np.ndarray,
np.ndarray,
Optional[np.ndarray],
Optional[np.ndarray],
Dict[str, List[np.ndarray]],
]:
if not roboflow_result["predictions"]:
return (
np.empty((0, 4)),
np.empty(0),
np.empty(0),
None,
None,
{CLASS_NAME_DATA_FIELD: np.empty(0)},
)
xyxy = []
confidence = []
class_id = []
class_name = []
masks = []
tracker_ids = []
image_width = int(roboflow_result["image"]["width"])
image_height = int(roboflow_result["image"]["height"])
for prediction in roboflow_result["predictions"]:
x = prediction["x"]
y = prediction["y"]
width = prediction["width"]
height = prediction["height"]
x_min = x - width / 2
y_min = y - height / 2
x_max = x_min + width
y_max = y_min + height
if "points" not in prediction:
xyxy.append([x_min, y_min, x_max, y_max])
class_id.append(prediction["class_id"])
class_name.append(prediction["class"])
confidence.append(prediction["confidence"])
if "tracker_id" in prediction:
tracker_ids.append(prediction["tracker_id"])
elif len(prediction["points"]) >= 3:
polygon = np.array(
[[point["x"], point["y"]] for point in prediction["points"]], dtype=int
)
mask = polygon_to_mask(polygon, resolution_wh=(image_width, image_height))
xyxy.append([x_min, y_min, x_max, y_max])
class_id.append(prediction["class_id"])
class_name.append(prediction["class"])
confidence.append(prediction["confidence"])
masks.append(mask)
if "tracker_id" in prediction:
tracker_ids.append(prediction["tracker_id"])
xyxy = np.array(xyxy) if len(xyxy) > 0 else np.empty((0, 4))
confidence = np.array(confidence) if len(confidence) > 0 else np.empty(0)
class_id = np.array(class_id).astype(int) if len(class_id) > 0 else np.empty(0)
class_name = np.array(class_name) if len(class_name) > 0 else np.empty(0)
masks = np.array(masks, dtype=bool) if len(masks) > 0 else None
tracker_id = np.array(tracker_ids).astype(int) if len(tracker_ids) > 0 else None
data = {CLASS_NAME_DATA_FIELD: class_name}
return xyxy, confidence, class_id, masks, tracker_id, data
def move_boxes(xyxy: np.ndarray, offset: np.ndarray) -> np.ndarray:
"""
Parameters:
xyxy (np.ndarray): An array of shape `(n, 4)` containing the bounding boxes
coordinates in format `[x1, y1, x2, y2]`
offset (np.array): An array of shape `(2,)` containing offset values in format
is `[dx, dy]`.
Returns:
np.ndarray: Repositioned bounding boxes.
Example:
```python
import numpy as np
import supervision as sv
boxes = np.array([[10, 10, 20, 20], [30, 30, 40, 40]])
offset = np.array([5, 5])
moved_box = sv.move_boxes(boxes, offset)
print(moved_box)
# np.array([
# [15, 15, 25, 25],
# [35, 35, 45, 45]
# ])
```
"""
return xyxy + np.hstack([offset, offset])
def scale_boxes(xyxy: np.ndarray, factor: float) -> np.ndarray:
"""
Scale the dimensions of bounding boxes.
Parameters:
xyxy (np.ndarray): An array of shape `(n, 4)` containing the bounding boxes
coordinates in format `[x1, y1, x2, y2]`
factor (float): A float value representing the factor by which the box
dimensions are scaled. A factor greater than 1 enlarges the boxes, while a
factor less than 1 shrinks them.
Returns:
np.ndarray: Scaled bounding boxes.
Example:
```python
import numpy as np
import supervision as sv
boxes = np.array([[10, 10, 20, 20], [30, 30, 40, 40]])
factor = 1.5
scaled_bb = sv.scale_boxes(boxes, factor)
print(scaled_bb)
# np.array([
# [ 7.5, 7.5, 22.5, 22.5],
# [27.5, 27.5, 42.5, 42.5]
# ])
```
"""
centers = (xyxy[:, :2] + xyxy[:, 2:]) / 2
new_sizes = (xyxy[:, 2:] - xyxy[:, :2]) * factor
return np.concatenate((centers - new_sizes / 2, centers + new_sizes / 2), axis=1)
def calculate_masks_centroids(masks: np.ndarray) -> np.ndarray:
"""
Calculate the centroids of binary masks in a tensor.
Parameters:
masks (np.ndarray): A 3D NumPy array of shape (num_masks, height, width).
Each 2D array in the tensor represents a binary mask.
Returns:
A 2D NumPy array of shape (num_masks, 2), where each row contains the x and y
coordinates (in that order) of the centroid of the corresponding mask.
"""
num_masks, height, width = masks.shape
total_pixels = masks.sum(axis=(1, 2))
# offset for 1-based indexing
vertical_indices, horizontal_indices = np.indices((height, width)) + 0.5
# avoid division by zero for empty masks
total_pixels[total_pixels == 0] = 1
def sum_over_mask(indices: np.ndarray, axis: tuple) -> np.ndarray:
return np.tensordot(masks, indices, axes=axis)
aggregation_axis = ([1, 2], [0, 1])
centroid_x = sum_over_mask(horizontal_indices, aggregation_axis) / total_pixels
centroid_y = sum_over_mask(vertical_indices, aggregation_axis) / total_pixels
return np.column_stack((centroid_x, centroid_y)).astype(int)
def validate_xyxy(xyxy: Any) -> None:
expected_shape = "(_, 4)"
actual_shape = str(getattr(xyxy, "shape", None))
is_valid = isinstance(xyxy, np.ndarray) and xyxy.ndim == 2 and xyxy.shape[1] == 4
if not is_valid:
raise ValueError(
f"xyxy must be a 2D np.ndarray with shape {expected_shape}, but got shape "
f"{actual_shape}"
)
def validate_mask(mask: Any, n: int) -> None:
expected_shape = f"({n}, H, W)"
actual_shape = str(getattr(mask, "shape", None))
is_valid = mask is None or (
isinstance(mask, np.ndarray) and len(mask.shape) == 3 and mask.shape[0] == n
)
if not is_valid:
raise ValueError(
f"mask must be a 3D np.ndarray with shape {expected_shape}, but got shape "
f"{actual_shape}"
)
def validate_class_id(class_id: Any, n: int) -> None:
expected_shape = f"({n},)"
actual_shape = str(getattr(class_id, "shape", None))
is_valid = class_id is None or (
isinstance(class_id, np.ndarray) and class_id.shape == (n,)
)
if not is_valid:
raise ValueError(
f"class_id must be a 1D np.ndarray with shape {expected_shape}, but got "
f"shape {actual_shape}"
)
def validate_confidence(confidence: Any, n: int) -> None:
expected_shape = f"({n},)"
actual_shape = str(getattr(confidence, "shape", None))
is_valid = confidence is None or (
isinstance(confidence, np.ndarray) and confidence.shape == (n,)
)
if not is_valid:
raise ValueError(
f"confidence must be a 1D np.ndarray with shape {expected_shape}, but got "
f"shape {actual_shape}"
)
def validate_tracker_id(tracker_id: Any, n: int) -> None:
expected_shape = f"({n},)"
actual_shape = str(getattr(tracker_id, "shape", None))
is_valid = tracker_id is None or (
isinstance(tracker_id, np.ndarray) and tracker_id.shape == (n,)
)
if not is_valid:
raise ValueError(
f"tracker_id must be a 1D np.ndarray with shape {expected_shape}, but got "
f"shape {actual_shape}"
)
def validate_data(data: Dict[str, Any], n: int) -> None:
for key, value in data.items():
if isinstance(value, list):
if len(value) != n:
raise ValueError(f"Length of list for key '{key}' must be {n}")
elif isinstance(value, np.ndarray):
if value.ndim == 1 and value.shape[0] != n:
raise ValueError(f"Shape of np.ndarray for key '{key}' must be ({n},)")
elif value.ndim > 1 and value.shape[0] != n:
raise ValueError(
f"First dimension of np.ndarray for key '{key}' must have size {n}"
)
else:
raise ValueError(f"Value for key '{key}' must be a list or np.ndarray")
def validate_detections_fields(
xyxy: Any,
mask: Any,
class_id: Any,
confidence: Any,
tracker_id: Any,
data: Dict[str, Any],
) -> None:
validate_xyxy(xyxy)
n = len(xyxy)
validate_mask(mask, n)
validate_class_id(class_id, n)
validate_confidence(confidence, n)
validate_tracker_id(tracker_id, n)
validate_data(data, n)
def is_data_equal(data_a: Dict[str, np.ndarray], data_b: Dict[str, np.ndarray]) -> bool:
"""
Compares the data payloads of two Detections instances.
Args:
data_a, data_b: The data payloads of the instances.
Returns:
True if the data payloads are equal, False otherwise.
"""
return set(data_a.keys()) == set(data_b.keys()) and all(
np.array_equal(data_a[key], data_b[key]) for key in data_a
)
def merge_data(
data_list: List[Dict[str, Union[np.ndarray, List]]],
) -> Dict[str, Union[np.ndarray, List]]:
"""
Merges the data payloads of a list of Detections instances.
Args:
data_list: The data payloads of the instances.
Returns:
A single data payload containing the merged data, preserving the original data
types (list or np.ndarray).
Raises:
ValueError: If data values within a single object have different lengths or if
dictionaries have different keys.
"""
if not data_list:
return {}
all_keys_sets = [set(data.keys()) for data in data_list]
if not all(keys_set == all_keys_sets[0] for keys_set in all_keys_sets):
raise ValueError("All data dictionaries must have the same keys to merge.")
for data in data_list:
lengths = [len(value) for value in data.values()]
if len(set(lengths)) > 1:
raise ValueError(
"All data values within a single object must have equal length."
)
merged_data = {key: [] for key in all_keys_sets[0]}
for data in data_list:
for key in merged_data:
merged_data[key].append(data[key])
for key in merged_data:
if all(isinstance(item, list) for item in merged_data[key]):
merged_data[key] = list(chain.from_iterable(merged_data[key]))
elif all(isinstance(item, np.ndarray) for item in merged_data[key]):
ndim = merged_data[key][0].ndim
if ndim == 1:
merged_data[key] = np.hstack(merged_data[key])
elif ndim > 1:
merged_data[key] = np.vstack(merged_data[key])
else:
raise ValueError(f"Unexpected array dimension for key '{key}'.")
else:
raise ValueError(
f"Inconsistent data types for key '{key}'. Only np.ndarray and list "
f"types are allowed."
)
return merged_data
def get_data_item(
data: Dict[str, Union[np.ndarray, List]],
index: Union[int, slice, List[int], np.ndarray],
) -> Dict[str, Union[np.ndarray, List]]:
"""
Retrieve a subset of the data dictionary based on the given index.
Args:
data: The data dictionary of the Detections object.
index: The index or indices specifying the subset to retrieve.
Returns:
A subset of the data dictionary corresponding to the specified index.
"""
subset_data = {}
for key, value in data.items():
if isinstance(value, np.ndarray):
subset_data[key] = value[index]
elif isinstance(value, list):
if isinstance(index, slice):
subset_data[key] = value[index]
elif isinstance(index, (list, np.ndarray)):
subset_data[key] = [value[i] for i in index]
elif isinstance(index, int):
subset_data[key] = [value[index]]
else:
raise TypeError(f"Unsupported index type: {type(index)}")
else:
raise TypeError(f"Unsupported data type for key '{key}': {type(value)}")
return subset_data