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Reference for ultralytics/utils/ops.py

Note

This file is available at https://github.com/ultralytics/ultralytics/blob/main/ultralytics/utils/ops.py. If you spot a problem please help fix it by contributing a Pull Request ๐Ÿ› ๏ธ. Thank you ๐Ÿ™!



ultralytics.utils.ops.Profile

Bases: ContextDecorator

YOLOv8 Profile class. Use as a decorator with @Profile() or as a context manager with 'with Profile():'.

Example
from ultralytics.utils.ops import Profile

with Profile(device=device) as dt:
    pass  # slow operation here

print(dt)  # prints "Elapsed time is 9.5367431640625e-07 s"
Source code in ultralytics/utils/ops.py
class Profile(contextlib.ContextDecorator):
    """
    YOLOv8 Profile class. Use as a decorator with @Profile() or as a context manager with 'with Profile():'.

    Example:
        ```python
        from ultralytics.utils.ops import Profile

        with Profile(device=device) as dt:
            pass  # slow operation here

        print(dt)  # prints "Elapsed time is 9.5367431640625e-07 s"
        ```
    """

    def __init__(self, t=0.0, device: torch.device = None):
        """
        Initialize the Profile class.

        Args:
            t (float): Initial time. Defaults to 0.0.
            device (torch.device): Devices used for model inference. Defaults to None (cpu).
        """
        self.t = t
        self.device = device
        self.cuda = bool(device and str(device).startswith("cuda"))

    def __enter__(self):
        """Start timing."""
        self.start = self.time()
        return self

    def __exit__(self, type, value, traceback):  # noqa
        """Stop timing."""
        self.dt = self.time() - self.start  # delta-time
        self.t += self.dt  # accumulate dt

    def __str__(self):
        """Returns a human-readable string representing the accumulated elapsed time in the profiler."""
        return f"Elapsed time is {self.t} s"

    def time(self):
        """Get current time."""
        if self.cuda:
            torch.cuda.synchronize(self.device)
        return time.time()

__enter__()

Start timing.

Source code in ultralytics/utils/ops.py
def __enter__(self):
    """Start timing."""
    self.start = self.time()
    return self

__exit__(type, value, traceback)

Stop timing.

Source code in ultralytics/utils/ops.py
def __exit__(self, type, value, traceback):  # noqa
    """Stop timing."""
    self.dt = self.time() - self.start  # delta-time
    self.t += self.dt  # accumulate dt

__init__(t=0.0, device=None)

Initialize the Profile class.

Parameters:

Name Type Description Default
t float

Initial time. Defaults to 0.0.

0.0
device device

Devices used for model inference. Defaults to None (cpu).

None
Source code in ultralytics/utils/ops.py
def __init__(self, t=0.0, device: torch.device = None):
    """
    Initialize the Profile class.

    Args:
        t (float): Initial time. Defaults to 0.0.
        device (torch.device): Devices used for model inference. Defaults to None (cpu).
    """
    self.t = t
    self.device = device
    self.cuda = bool(device and str(device).startswith("cuda"))

__str__()

Returns a human-readable string representing the accumulated elapsed time in the profiler.

Source code in ultralytics/utils/ops.py
def __str__(self):
    """Returns a human-readable string representing the accumulated elapsed time in the profiler."""
    return f"Elapsed time is {self.t} s"

time()

Get current time.

Source code in ultralytics/utils/ops.py
def time(self):
    """Get current time."""
    if self.cuda:
        torch.cuda.synchronize(self.device)
    return time.time()



ultralytics.utils.ops.segment2box(segment, width=640, height=640)

Convert 1 segment label to 1 box label, applying inside-image constraint, i.e. (xy1, xy2, ...) to (xyxy).

Parameters:

Name Type Description Default
segment Tensor

the segment label

required
width int

the width of the image. Defaults to 640

640
height int

The height of the image. Defaults to 640

640

Returns:

Type Description
ndarray

the minimum and maximum x and y values of the segment.

Source code in ultralytics/utils/ops.py
def segment2box(segment, width=640, height=640):
    """
    Convert 1 segment label to 1 box label, applying inside-image constraint, i.e. (xy1, xy2, ...) to (xyxy).

    Args:
        segment (torch.Tensor): the segment label
        width (int): the width of the image. Defaults to 640
        height (int): The height of the image. Defaults to 640

    Returns:
        (np.ndarray): the minimum and maximum x and y values of the segment.
    """
    x, y = segment.T  # segment xy
    inside = (x >= 0) & (y >= 0) & (x <= width) & (y <= height)
    x = x[inside]
    y = y[inside]
    return (
        np.array([x.min(), y.min(), x.max(), y.max()], dtype=segment.dtype)
        if any(x)
        else np.zeros(4, dtype=segment.dtype)
    )  # xyxy



ultralytics.utils.ops.scale_boxes(img1_shape, boxes, img0_shape, ratio_pad=None, padding=True, xywh=False)

Rescales bounding boxes (in the format of xyxy by default) from the shape of the image they were originally specified in (img1_shape) to the shape of a different image (img0_shape).

Parameters:

Name Type Description Default
img1_shape tuple

The shape of the image that the bounding boxes are for, in the format of (height, width).

required
boxes Tensor

the bounding boxes of the objects in the image, in the format of (x1, y1, x2, y2)

required
img0_shape tuple

the shape of the target image, in the format of (height, width).

required
ratio_pad tuple

a tuple of (ratio, pad) for scaling the boxes. If not provided, the ratio and pad will be calculated based on the size difference between the two images.

None
padding bool

If True, assuming the boxes is based on image augmented by yolo style. If False then do regular rescaling.

True
xywh bool

The box format is xywh or not, default=False.

False

Returns:

Name Type Description
boxes Tensor

The scaled bounding boxes, in the format of (x1, y1, x2, y2)

Source code in ultralytics/utils/ops.py
def scale_boxes(img1_shape, boxes, img0_shape, ratio_pad=None, padding=True, xywh=False):
    """
    Rescales bounding boxes (in the format of xyxy by default) from the shape of the image they were originally
    specified in (img1_shape) to the shape of a different image (img0_shape).

    Args:
        img1_shape (tuple): The shape of the image that the bounding boxes are for, in the format of (height, width).
        boxes (torch.Tensor): the bounding boxes of the objects in the image, in the format of (x1, y1, x2, y2)
        img0_shape (tuple): the shape of the target image, in the format of (height, width).
        ratio_pad (tuple): a tuple of (ratio, pad) for scaling the boxes. If not provided, the ratio and pad will be
            calculated based on the size difference between the two images.
        padding (bool): If True, assuming the boxes is based on image augmented by yolo style. If False then do regular
            rescaling.
        xywh (bool): The box format is xywh or not, default=False.

    Returns:
        boxes (torch.Tensor): The scaled bounding boxes, in the format of (x1, y1, x2, y2)
    """
    if ratio_pad is None:  # calculate from img0_shape
        gain = min(img1_shape[0] / img0_shape[0], img1_shape[1] / img0_shape[1])  # gain  = old / new
        pad = (
            round((img1_shape[1] - img0_shape[1] * gain) / 2 - 0.1),
            round((img1_shape[0] - img0_shape[0] * gain) / 2 - 0.1),
        )  # wh padding
    else:
        gain = ratio_pad[0][0]
        pad = ratio_pad[1]

    if padding:
        boxes[..., 0] -= pad[0]  # x padding
        boxes[..., 1] -= pad[1]  # y padding
        if not xywh:
            boxes[..., 2] -= pad[0]  # x padding
            boxes[..., 3] -= pad[1]  # y padding
    boxes[..., :4] /= gain
    return clip_boxes(boxes, img0_shape)



ultralytics.utils.ops.make_divisible(x, divisor)

Returns the nearest number that is divisible by the given divisor.

Parameters:

Name Type Description Default
x int

The number to make divisible.

required
divisor int | Tensor

The divisor.

required

Returns:

Type Description
int

The nearest number divisible by the divisor.

Source code in ultralytics/utils/ops.py
def make_divisible(x, divisor):
    """
    Returns the nearest number that is divisible by the given divisor.

    Args:
        x (int): The number to make divisible.
        divisor (int | torch.Tensor): The divisor.

    Returns:
        (int): The nearest number divisible by the divisor.
    """
    if isinstance(divisor, torch.Tensor):
        divisor = int(divisor.max())  # to int
    return math.ceil(x / divisor) * divisor



ultralytics.utils.ops.nms_rotated(boxes, scores, threshold=0.45)

NMS for obbs, powered by probiou and fast-nms.

Parameters:

Name Type Description Default
boxes Tensor

(N, 5), xywhr.

required
scores Tensor

(N, ).

required
threshold float

Iou threshold.

0.45

Returns:

Source code in ultralytics/utils/ops.py
def nms_rotated(boxes, scores, threshold=0.45):
    """
    NMS for obbs, powered by probiou and fast-nms.

    Args:
        boxes (torch.Tensor): (N, 5), xywhr.
        scores (torch.Tensor): (N, ).
        threshold (float): Iou threshold.

    Returns:
    """
    if len(boxes) == 0:
        return np.empty((0,), dtype=np.int8)
    sorted_idx = torch.argsort(scores, descending=True)
    boxes = boxes[sorted_idx]
    ious = batch_probiou(boxes, boxes).triu_(diagonal=1)
    pick = torch.nonzero(ious.max(dim=0)[0] < threshold).squeeze_(-1)
    return sorted_idx[pick]



ultralytics.utils.ops.non_max_suppression(prediction, conf_thres=0.25, iou_thres=0.45, classes=None, agnostic=False, multi_label=False, labels=(), max_det=300, nc=0, max_time_img=0.05, max_nms=30000, max_wh=7680, in_place=True, rotated=False)

Perform non-maximum suppression (NMS) on a set of boxes, with support for masks and multiple labels per box.

Parameters:

Name Type Description Default
prediction Tensor

A tensor of shape (batch_size, num_classes + 4 + num_masks, num_boxes) containing the predicted boxes, classes, and masks. The tensor should be in the format output by a model, such as YOLO.

required
conf_thres float

The confidence threshold below which boxes will be filtered out. Valid values are between 0.0 and 1.0.

0.25
iou_thres float

The IoU threshold below which boxes will be filtered out during NMS. Valid values are between 0.0 and 1.0.

0.45
classes List[int]

A list of class indices to consider. If None, all classes will be considered.

None
agnostic bool

If True, the model is agnostic to the number of classes, and all classes will be considered as one.

False
multi_label bool

If True, each box may have multiple labels.

False
labels List[List[Union[int, float, Tensor]]]

A list of lists, where each inner list contains the apriori labels for a given image. The list should be in the format output by a dataloader, with each label being a tuple of (class_index, x1, y1, x2, y2).

()
max_det int

The maximum number of boxes to keep after NMS.

300
nc int

The number of classes output by the model. Any indices after this will be considered masks.

0
max_time_img float

The maximum time (seconds) for processing one image.

0.05
max_nms int

The maximum number of boxes into torchvision.ops.nms().

30000
max_wh int

The maximum box width and height in pixels.

7680
in_place bool

If True, the input prediction tensor will be modified in place.

True

Returns:

Type Description
List[Tensor]

A list of length batch_size, where each element is a tensor of shape (num_boxes, 6 + num_masks) containing the kept boxes, with columns (x1, y1, x2, y2, confidence, class, mask1, mask2, ...).

Source code in ultralytics/utils/ops.py
def non_max_suppression(
    prediction,
    conf_thres=0.25,
    iou_thres=0.45,
    classes=None,
    agnostic=False,
    multi_label=False,
    labels=(),
    max_det=300,
    nc=0,  # number of classes (optional)
    max_time_img=0.05,
    max_nms=30000,
    max_wh=7680,
    in_place=True,
    rotated=False,
):
    """
    Perform non-maximum suppression (NMS) on a set of boxes, with support for masks and multiple labels per box.

    Args:
        prediction (torch.Tensor): A tensor of shape (batch_size, num_classes + 4 + num_masks, num_boxes)
            containing the predicted boxes, classes, and masks. The tensor should be in the format
            output by a model, such as YOLO.
        conf_thres (float): The confidence threshold below which boxes will be filtered out.
            Valid values are between 0.0 and 1.0.
        iou_thres (float): The IoU threshold below which boxes will be filtered out during NMS.
            Valid values are between 0.0 and 1.0.
        classes (List[int]): A list of class indices to consider. If None, all classes will be considered.
        agnostic (bool): If True, the model is agnostic to the number of classes, and all
            classes will be considered as one.
        multi_label (bool): If True, each box may have multiple labels.
        labels (List[List[Union[int, float, torch.Tensor]]]): A list of lists, where each inner
            list contains the apriori labels for a given image. The list should be in the format
            output by a dataloader, with each label being a tuple of (class_index, x1, y1, x2, y2).
        max_det (int): The maximum number of boxes to keep after NMS.
        nc (int, optional): The number of classes output by the model. Any indices after this will be considered masks.
        max_time_img (float): The maximum time (seconds) for processing one image.
        max_nms (int): The maximum number of boxes into torchvision.ops.nms().
        max_wh (int): The maximum box width and height in pixels.
        in_place (bool): If True, the input prediction tensor will be modified in place.

    Returns:
        (List[torch.Tensor]): A list of length batch_size, where each element is a tensor of
            shape (num_boxes, 6 + num_masks) containing the kept boxes, with columns
            (x1, y1, x2, y2, confidence, class, mask1, mask2, ...).
    """

    # Checks
    assert 0 <= conf_thres <= 1, f"Invalid Confidence threshold {conf_thres}, valid values are between 0.0 and 1.0"
    assert 0 <= iou_thres <= 1, f"Invalid IoU {iou_thres}, valid values are between 0.0 and 1.0"
    if isinstance(prediction, (list, tuple)):  # YOLOv8 model in validation model, output = (inference_out, loss_out)
        prediction = prediction[0]  # select only inference output

    bs = prediction.shape[0]  # batch size
    nc = nc or (prediction.shape[1] - 4)  # number of classes
    nm = prediction.shape[1] - nc - 4
    mi = 4 + nc  # mask start index
    xc = prediction[:, 4:mi].amax(1) > conf_thres  # candidates

    # Settings
    # min_wh = 2  # (pixels) minimum box width and height
    time_limit = 2.0 + max_time_img * bs  # seconds to quit after
    multi_label &= nc > 1  # multiple labels per box (adds 0.5ms/img)

    prediction = prediction.transpose(-1, -2)  # shape(1,84,6300) to shape(1,6300,84)
    if not rotated:
        if in_place:
            prediction[..., :4] = xywh2xyxy(prediction[..., :4])  # xywh to xyxy
        else:
            prediction = torch.cat((xywh2xyxy(prediction[..., :4]), prediction[..., 4:]), dim=-1)  # xywh to xyxy

    t = time.time()
    output = [torch.zeros((0, 6 + nm), device=prediction.device)] * bs
    for xi, x in enumerate(prediction):  # image index, image inference
        # Apply constraints
        # x[((x[:, 2:4] < min_wh) | (x[:, 2:4] > max_wh)).any(1), 4] = 0  # width-height
        x = x[xc[xi]]  # confidence

        # Cat apriori labels if autolabelling
        if labels and len(labels[xi]) and not rotated:
            lb = labels[xi]
            v = torch.zeros((len(lb), nc + nm + 4), device=x.device)
            v[:, :4] = xywh2xyxy(lb[:, 1:5])  # box
            v[range(len(lb)), lb[:, 0].long() + 4] = 1.0  # cls
            x = torch.cat((x, v), 0)

        # If none remain process next image
        if not x.shape[0]:
            continue

        # Detections matrix nx6 (xyxy, conf, cls)
        box, cls, mask = x.split((4, nc, nm), 1)

        if multi_label:
            i, j = torch.where(cls > conf_thres)
            x = torch.cat((box[i], x[i, 4 + j, None], j[:, None].float(), mask[i]), 1)
        else:  # best class only
            conf, j = cls.max(1, keepdim=True)
            x = torch.cat((box, conf, j.float(), mask), 1)[conf.view(-1) > conf_thres]

        # Filter by class
        if classes is not None:
            x = x[(x[:, 5:6] == torch.tensor(classes, device=x.device)).any(1)]

        # Check shape
        n = x.shape[0]  # number of boxes
        if not n:  # no boxes
            continue
        if n > max_nms:  # excess boxes
            x = x[x[:, 4].argsort(descending=True)[:max_nms]]  # sort by confidence and remove excess boxes

        # Batched NMS
        c = x[:, 5:6] * (0 if agnostic else max_wh)  # classes
        scores = x[:, 4]  # scores
        if rotated:
            boxes = torch.cat((x[:, :2] + c, x[:, 2:4], x[:, -1:]), dim=-1)  # xywhr
            i = nms_rotated(boxes, scores, iou_thres)
        else:
            boxes = x[:, :4] + c  # boxes (offset by class)
            i = torchvision.ops.nms(boxes, scores, iou_thres)  # NMS
        i = i[:max_det]  # limit detections

        # # Experimental
        # merge = False  # use merge-NMS
        # if merge and (1 < n < 3E3):  # Merge NMS (boxes merged using weighted mean)
        #     # Update boxes as boxes(i,4) = weights(i,n) * boxes(n,4)
        #     from .metrics import box_iou
        #     iou = box_iou(boxes[i], boxes) > iou_thres  # iou matrix
        #     weights = iou * scores[None]  # box weights
        #     x[i, :4] = torch.mm(weights, x[:, :4]).float() / weights.sum(1, keepdim=True)  # merged boxes
        #     redundant = True  # require redundant detections
        #     if redundant:
        #         i = i[iou.sum(1) > 1]  # require redundancy

        output[xi] = x[i]
        if (time.time() - t) > time_limit:
            LOGGER.warning(f"WARNING โš ๏ธ NMS time limit {time_limit:.3f}s exceeded")
            break  # time limit exceeded

    return output



ultralytics.utils.ops.clip_boxes(boxes, shape)

Takes a list of bounding boxes and a shape (height, width) and clips the bounding boxes to the shape.

Parameters:

Name Type Description Default
boxes Tensor

the bounding boxes to clip

required
shape tuple

the shape of the image

required

Returns:

Type Description
Tensor | ndarray

Clipped boxes

Source code in ultralytics/utils/ops.py
def clip_boxes(boxes, shape):
    """
    Takes a list of bounding boxes and a shape (height, width) and clips the bounding boxes to the shape.

    Args:
        boxes (torch.Tensor): the bounding boxes to clip
        shape (tuple): the shape of the image

    Returns:
        (torch.Tensor | numpy.ndarray): Clipped boxes
    """
    if isinstance(boxes, torch.Tensor):  # faster individually (WARNING: inplace .clamp_() Apple MPS bug)
        boxes[..., 0] = boxes[..., 0].clamp(0, shape[1])  # x1
        boxes[..., 1] = boxes[..., 1].clamp(0, shape[0])  # y1
        boxes[..., 2] = boxes[..., 2].clamp(0, shape[1])  # x2
        boxes[..., 3] = boxes[..., 3].clamp(0, shape[0])  # y2
    else:  # np.array (faster grouped)
        boxes[..., [0, 2]] = boxes[..., [0, 2]].clip(0, shape[1])  # x1, x2
        boxes[..., [1, 3]] = boxes[..., [1, 3]].clip(0, shape[0])  # y1, y2
    return boxes



ultralytics.utils.ops.clip_coords(coords, shape)

Clip line coordinates to the image boundaries.

Parameters:

Name Type Description Default
coords Tensor | ndarray

A list of line coordinates.

required
shape tuple

A tuple of integers representing the size of the image in the format (height, width).

required

Returns:

Type Description
Tensor | ndarray

Clipped coordinates

Source code in ultralytics/utils/ops.py
def clip_coords(coords, shape):
    """
    Clip line coordinates to the image boundaries.

    Args:
        coords (torch.Tensor | numpy.ndarray): A list of line coordinates.
        shape (tuple): A tuple of integers representing the size of the image in the format (height, width).

    Returns:
        (torch.Tensor | numpy.ndarray): Clipped coordinates
    """
    if isinstance(coords, torch.Tensor):  # faster individually (WARNING: inplace .clamp_() Apple MPS bug)
        coords[..., 0] = coords[..., 0].clamp(0, shape[1])  # x
        coords[..., 1] = coords[..., 1].clamp(0, shape[0])  # y
    else:  # np.array (faster grouped)
        coords[..., 0] = coords[..., 0].clip(0, shape[1])  # x
        coords[..., 1] = coords[..., 1].clip(0, shape[0])  # y
    return coords



ultralytics.utils.ops.scale_image(masks, im0_shape, ratio_pad=None)

Takes a mask, and resizes it to the original image size.

Parameters:

Name Type Description Default
masks ndarray

resized and padded masks/images, [h, w, num]/[h, w, 3].

required
im0_shape tuple

the original image shape

required
ratio_pad tuple

the ratio of the padding to the original image.

None

Returns:

Name Type Description
masks Tensor

The masks that are being returned.

Source code in ultralytics/utils/ops.py
def scale_image(masks, im0_shape, ratio_pad=None):
    """
    Takes a mask, and resizes it to the original image size.

    Args:
        masks (np.ndarray): resized and padded masks/images, [h, w, num]/[h, w, 3].
        im0_shape (tuple): the original image shape
        ratio_pad (tuple): the ratio of the padding to the original image.

    Returns:
        masks (torch.Tensor): The masks that are being returned.
    """
    # Rescale coordinates (xyxy) from im1_shape to im0_shape
    im1_shape = masks.shape
    if im1_shape[:2] == im0_shape[:2]:
        return masks
    if ratio_pad is None:  # calculate from im0_shape
        gain = min(im1_shape[0] / im0_shape[0], im1_shape[1] / im0_shape[1])  # gain  = old / new
        pad = (im1_shape[1] - im0_shape[1] * gain) / 2, (im1_shape[0] - im0_shape[0] * gain) / 2  # wh padding
    else:
        # gain = ratio_pad[0][0]
        pad = ratio_pad[1]
    top, left = int(pad[1]), int(pad[0])  # y, x
    bottom, right = int(im1_shape[0] - pad[1]), int(im1_shape[1] - pad[0])

    if len(masks.shape) < 2:
        raise ValueError(f'"len of masks shape" should be 2 or 3, but got {len(masks.shape)}')
    masks = masks[top:bottom, left:right]
    masks = cv2.resize(masks, (im0_shape[1], im0_shape[0]))
    if len(masks.shape) == 2:
        masks = masks[:, :, None]

    return masks



ultralytics.utils.ops.xyxy2xywh(x)

Convert bounding box coordinates from (x1, y1, x2, y2) format to (x, y, width, height) format where (x1, y1) is the top-left corner and (x2, y2) is the bottom-right corner.

Parameters:

Name Type Description Default
x ndarray | Tensor

The input bounding box coordinates in (x1, y1, x2, y2) format.

required

Returns:

Name Type Description
y ndarray | Tensor

The bounding box coordinates in (x, y, width, height) format.

Source code in ultralytics/utils/ops.py
def xyxy2xywh(x):
    """
    Convert bounding box coordinates from (x1, y1, x2, y2) format to (x, y, width, height) format where (x1, y1) is the
    top-left corner and (x2, y2) is the bottom-right corner.

    Args:
        x (np.ndarray | torch.Tensor): The input bounding box coordinates in (x1, y1, x2, y2) format.

    Returns:
        y (np.ndarray | torch.Tensor): The bounding box coordinates in (x, y, width, height) format.
    """
    assert x.shape[-1] == 4, f"input shape last dimension expected 4 but input shape is {x.shape}"
    y = torch.empty_like(x) if isinstance(x, torch.Tensor) else np.empty_like(x)  # faster than clone/copy
    y[..., 0] = (x[..., 0] + x[..., 2]) / 2  # x center
    y[..., 1] = (x[..., 1] + x[..., 3]) / 2  # y center
    y[..., 2] = x[..., 2] - x[..., 0]  # width
    y[..., 3] = x[..., 3] - x[..., 1]  # height
    return y



ultralytics.utils.ops.xywh2xyxy(x)

Convert bounding box coordinates from (x, y, width, height) format to (x1, y1, x2, y2) format where (x1, y1) is the top-left corner and (x2, y2) is the bottom-right corner.

Parameters:

Name Type Description Default
x ndarray | Tensor

The input bounding box coordinates in (x, y, width, height) format.

required

Returns:

Name Type Description
y ndarray | Tensor

The bounding box coordinates in (x1, y1, x2, y2) format.

Source code in ultralytics/utils/ops.py
def xywh2xyxy(x):
    """
    Convert bounding box coordinates from (x, y, width, height) format to (x1, y1, x2, y2) format where (x1, y1) is the
    top-left corner and (x2, y2) is the bottom-right corner.

    Args:
        x (np.ndarray | torch.Tensor): The input bounding box coordinates in (x, y, width, height) format.

    Returns:
        y (np.ndarray | torch.Tensor): The bounding box coordinates in (x1, y1, x2, y2) format.
    """
    assert x.shape[-1] == 4, f"input shape last dimension expected 4 but input shape is {x.shape}"
    y = torch.empty_like(x) if isinstance(x, torch.Tensor) else np.empty_like(x)  # faster than clone/copy
    dw = x[..., 2] / 2  # half-width
    dh = x[..., 3] / 2  # half-height
    y[..., 0] = x[..., 0] - dw  # top left x
    y[..., 1] = x[..., 1] - dh  # top left y
    y[..., 2] = x[..., 0] + dw  # bottom right x
    y[..., 3] = x[..., 1] + dh  # bottom right y
    return y



ultralytics.utils.ops.xywhn2xyxy(x, w=640, h=640, padw=0, padh=0)

Convert normalized bounding box coordinates to pixel coordinates.

Parameters:

Name Type Description Default
x ndarray | Tensor

The bounding box coordinates.

required
w int

Width of the image. Defaults to 640

640
h int

Height of the image. Defaults to 640

640
padw int

Padding width. Defaults to 0

0
padh int

Padding height. Defaults to 0

0

Returns: y (np.ndarray | torch.Tensor): The coordinates of the bounding box in the format [x1, y1, x2, y2] where x1,y1 is the top-left corner, x2,y2 is the bottom-right corner of the bounding box.

Source code in ultralytics/utils/ops.py
def xywhn2xyxy(x, w=640, h=640, padw=0, padh=0):
    """
    Convert normalized bounding box coordinates to pixel coordinates.

    Args:
        x (np.ndarray | torch.Tensor): The bounding box coordinates.
        w (int): Width of the image. Defaults to 640
        h (int): Height of the image. Defaults to 640
        padw (int): Padding width. Defaults to 0
        padh (int): Padding height. Defaults to 0
    Returns:
        y (np.ndarray | torch.Tensor): The coordinates of the bounding box in the format [x1, y1, x2, y2] where
            x1,y1 is the top-left corner, x2,y2 is the bottom-right corner of the bounding box.
    """
    assert x.shape[-1] == 4, f"input shape last dimension expected 4 but input shape is {x.shape}"
    y = torch.empty_like(x) if isinstance(x, torch.Tensor) else np.empty_like(x)  # faster than clone/copy
    y[..., 0] = w * (x[..., 0] - x[..., 2] / 2) + padw  # top left x
    y[..., 1] = h * (x[..., 1] - x[..., 3] / 2) + padh  # top left y
    y[..., 2] = w * (x[..., 0] + x[..., 2] / 2) + padw  # bottom right x
    y[..., 3] = h * (x[..., 1] + x[..., 3] / 2) + padh  # bottom right y
    return y



ultralytics.utils.ops.xyxy2xywhn(x, w=640, h=640, clip=False, eps=0.0)

Convert bounding box coordinates from (x1, y1, x2, y2) format to (x, y, width, height, normalized) format. x, y, width and height are normalized to image dimensions.

Parameters:

Name Type Description Default
x ndarray | Tensor

The input bounding box coordinates in (x1, y1, x2, y2) format.

required
w int

The width of the image. Defaults to 640

640
h int

The height of the image. Defaults to 640

640
clip bool

If True, the boxes will be clipped to the image boundaries. Defaults to False

False
eps float

The minimum value of the box's width and height. Defaults to 0.0

0.0

Returns:

Name Type Description
y ndarray | Tensor

The bounding box coordinates in (x, y, width, height, normalized) format

Source code in ultralytics/utils/ops.py
def xyxy2xywhn(x, w=640, h=640, clip=False, eps=0.0):
    """
    Convert bounding box coordinates from (x1, y1, x2, y2) format to (x, y, width, height, normalized) format. x, y,
    width and height are normalized to image dimensions.

    Args:
        x (np.ndarray | torch.Tensor): The input bounding box coordinates in (x1, y1, x2, y2) format.
        w (int): The width of the image. Defaults to 640
        h (int): The height of the image. Defaults to 640
        clip (bool): If True, the boxes will be clipped to the image boundaries. Defaults to False
        eps (float): The minimum value of the box's width and height. Defaults to 0.0

    Returns:
        y (np.ndarray | torch.Tensor): The bounding box coordinates in (x, y, width, height, normalized) format
    """
    if clip:
        x = clip_boxes(x, (h - eps, w - eps))
    assert x.shape[-1] == 4, f"input shape last dimension expected 4 but input shape is {x.shape}"
    y = torch.empty_like(x) if isinstance(x, torch.Tensor) else np.empty_like(x)  # faster than clone/copy
    y[..., 0] = ((x[..., 0] + x[..., 2]) / 2) / w  # x center
    y[..., 1] = ((x[..., 1] + x[..., 3]) / 2) / h  # y center
    y[..., 2] = (x[..., 2] - x[..., 0]) / w  # width
    y[..., 3] = (x[..., 3] - x[..., 1]) / h  # height
    return y



ultralytics.utils.ops.xywh2ltwh(x)

Convert the bounding box format from [x, y, w, h] to [x1, y1, w, h], where x1, y1 are the top-left coordinates.

Parameters:

Name Type Description Default
x ndarray | Tensor

The input tensor with the bounding box coordinates in the xywh format

required

Returns:

Name Type Description
y ndarray | Tensor

The bounding box coordinates in the xyltwh format

Source code in ultralytics/utils/ops.py
def xywh2ltwh(x):
    """
    Convert the bounding box format from [x, y, w, h] to [x1, y1, w, h], where x1, y1 are the top-left coordinates.

    Args:
        x (np.ndarray | torch.Tensor): The input tensor with the bounding box coordinates in the xywh format

    Returns:
        y (np.ndarray | torch.Tensor): The bounding box coordinates in the xyltwh format
    """
    y = x.clone() if isinstance(x, torch.Tensor) else np.copy(x)
    y[..., 0] = x[..., 0] - x[..., 2] / 2  # top left x
    y[..., 1] = x[..., 1] - x[..., 3] / 2  # top left y
    return y



ultralytics.utils.ops.xyxy2ltwh(x)

Convert nx4 bounding boxes from [x1, y1, x2, y2] to [x1, y1, w, h], where xy1=top-left, xy2=bottom-right.

Parameters:

Name Type Description Default
x ndarray | Tensor

The input tensor with the bounding boxes coordinates in the xyxy format

required

Returns:

Name Type Description
y ndarray | Tensor

The bounding box coordinates in the xyltwh format.

Source code in ultralytics/utils/ops.py
def xyxy2ltwh(x):
    """
    Convert nx4 bounding boxes from [x1, y1, x2, y2] to [x1, y1, w, h], where xy1=top-left, xy2=bottom-right.

    Args:
        x (np.ndarray | torch.Tensor): The input tensor with the bounding boxes coordinates in the xyxy format

    Returns:
        y (np.ndarray | torch.Tensor): The bounding box coordinates in the xyltwh format.
    """
    y = x.clone() if isinstance(x, torch.Tensor) else np.copy(x)
    y[..., 2] = x[..., 2] - x[..., 0]  # width
    y[..., 3] = x[..., 3] - x[..., 1]  # height
    return y



ultralytics.utils.ops.ltwh2xywh(x)

Convert nx4 boxes from [x1, y1, w, h] to [x, y, w, h] where xy1=top-left, xy=center.

Parameters:

Name Type Description Default
x Tensor

the input tensor

required

Returns:

Name Type Description
y ndarray | Tensor

The bounding box coordinates in the xywh format.

Source code in ultralytics/utils/ops.py
def ltwh2xywh(x):
    """
    Convert nx4 boxes from [x1, y1, w, h] to [x, y, w, h] where xy1=top-left, xy=center.

    Args:
        x (torch.Tensor): the input tensor

    Returns:
        y (np.ndarray | torch.Tensor): The bounding box coordinates in the xywh format.
    """
    y = x.clone() if isinstance(x, torch.Tensor) else np.copy(x)
    y[..., 0] = x[..., 0] + x[..., 2] / 2  # center x
    y[..., 1] = x[..., 1] + x[..., 3] / 2  # center y
    return y



ultralytics.utils.ops.xyxyxyxy2xywhr(corners)

Convert batched Oriented Bounding Boxes (OBB) from [xy1, xy2, xy3, xy4] to [xywh, rotation]. Rotation values are expected in degrees from 0 to 90.

Parameters:

Name Type Description Default
corners ndarray | Tensor

Input corners of shape (n, 8).

required

Returns:

Type Description
ndarray | Tensor

Converted data in [cx, cy, w, h, rotation] format of shape (n, 5).

Source code in ultralytics/utils/ops.py
def xyxyxyxy2xywhr(corners):
    """
    Convert batched Oriented Bounding Boxes (OBB) from [xy1, xy2, xy3, xy4] to [xywh, rotation]. Rotation values are
    expected in degrees from 0 to 90.

    Args:
        corners (numpy.ndarray | torch.Tensor): Input corners of shape (n, 8).

    Returns:
        (numpy.ndarray | torch.Tensor): Converted data in [cx, cy, w, h, rotation] format of shape (n, 5).
    """
    is_torch = isinstance(corners, torch.Tensor)
    points = corners.cpu().numpy() if is_torch else corners
    points = points.reshape(len(corners), -1, 2)
    rboxes = []
    for pts in points:
        # NOTE: Use cv2.minAreaRect to get accurate xywhr,
        # especially some objects are cut off by augmentations in dataloader.
        (x, y), (w, h), angle = cv2.minAreaRect(pts)
        rboxes.append([x, y, w, h, angle / 180 * np.pi])
    return (
        torch.tensor(rboxes, device=corners.device, dtype=corners.dtype)
        if is_torch
        else np.asarray(rboxes, dtype=points.dtype)
    )  # rboxes



ultralytics.utils.ops.xywhr2xyxyxyxy(rboxes)

Convert batched Oriented Bounding Boxes (OBB) from [xywh, rotation] to [xy1, xy2, xy3, xy4]. Rotation values should be in degrees from 0 to 90.

Parameters:

Name Type Description Default
rboxes ndarray | Tensor

Boxes in [cx, cy, w, h, rotation] format of shape (n, 5) or (b, n, 5).

required

Returns:

Type Description
ndarray | Tensor

Converted corner points of shape (n, 4, 2) or (b, n, 4, 2).

Source code in ultralytics/utils/ops.py
def xywhr2xyxyxyxy(rboxes):
    """
    Convert batched Oriented Bounding Boxes (OBB) from [xywh, rotation] to [xy1, xy2, xy3, xy4]. Rotation values should
    be in degrees from 0 to 90.

    Args:
        rboxes (numpy.ndarray | torch.Tensor): Boxes in [cx, cy, w, h, rotation] format of shape (n, 5) or (b, n, 5).

    Returns:
        (numpy.ndarray | torch.Tensor): Converted corner points of shape (n, 4, 2) or (b, n, 4, 2).
    """
    is_numpy = isinstance(rboxes, np.ndarray)
    cos, sin = (np.cos, np.sin) if is_numpy else (torch.cos, torch.sin)

    ctr = rboxes[..., :2]
    w, h, angle = (rboxes[..., i : i + 1] for i in range(2, 5))
    cos_value, sin_value = cos(angle), sin(angle)
    vec1 = [w / 2 * cos_value, w / 2 * sin_value]
    vec2 = [-h / 2 * sin_value, h / 2 * cos_value]
    vec1 = np.concatenate(vec1, axis=-1) if is_numpy else torch.cat(vec1, dim=-1)
    vec2 = np.concatenate(vec2, axis=-1) if is_numpy else torch.cat(vec2, dim=-1)
    pt1 = ctr + vec1 + vec2
    pt2 = ctr + vec1 - vec2
    pt3 = ctr - vec1 - vec2
    pt4 = ctr - vec1 + vec2
    return np.stack([pt1, pt2, pt3, pt4], axis=-2) if is_numpy else torch.stack([pt1, pt2, pt3, pt4], dim=-2)



ultralytics.utils.ops.ltwh2xyxy(x)

It converts the bounding box from [x1, y1, w, h] to [x1, y1, x2, y2] where xy1=top-left, xy2=bottom-right.

Parameters:

Name Type Description Default
x ndarray | Tensor

the input image

required

Returns:

Name Type Description
y ndarray | Tensor

the xyxy coordinates of the bounding boxes.

Source code in ultralytics/utils/ops.py
def ltwh2xyxy(x):
    """
    It converts the bounding box from [x1, y1, w, h] to [x1, y1, x2, y2] where xy1=top-left, xy2=bottom-right.

    Args:
        x (np.ndarray | torch.Tensor): the input image

    Returns:
        y (np.ndarray | torch.Tensor): the xyxy coordinates of the bounding boxes.
    """
    y = x.clone() if isinstance(x, torch.Tensor) else np.copy(x)
    y[..., 2] = x[..., 2] + x[..., 0]  # width
    y[..., 3] = x[..., 3] + x[..., 1]  # height
    return y



ultralytics.utils.ops.segments2boxes(segments)

It converts segment labels to box labels, i.e. (cls, xy1, xy2, ...) to (cls, xywh)

Parameters:

Name Type Description Default
segments list

list of segments, each segment is a list of points, each point is a list of x, y coordinates

required

Returns:

Type Description
ndarray

the xywh coordinates of the bounding boxes.

Source code in ultralytics/utils/ops.py
def segments2boxes(segments):
    """
    It converts segment labels to box labels, i.e. (cls, xy1, xy2, ...) to (cls, xywh)

    Args:
        segments (list): list of segments, each segment is a list of points, each point is a list of x, y coordinates

    Returns:
        (np.ndarray): the xywh coordinates of the bounding boxes.
    """
    boxes = []
    for s in segments:
        x, y = s.T  # segment xy
        boxes.append([x.min(), y.min(), x.max(), y.max()])  # cls, xyxy
    return xyxy2xywh(np.array(boxes))  # cls, xywh



ultralytics.utils.ops.resample_segments(segments, n=1000)

Inputs a list of segments (n,2) and returns a list of segments (n,2) up-sampled to n points each.

Parameters:

Name Type Description Default
segments list

a list of (n,2) arrays, where n is the number of points in the segment.

required
n int

number of points to resample the segment to. Defaults to 1000

1000

Returns:

Name Type Description
segments list

the resampled segments.

Source code in ultralytics/utils/ops.py
def resample_segments(segments, n=1000):
    """
    Inputs a list of segments (n,2) and returns a list of segments (n,2) up-sampled to n points each.

    Args:
        segments (list): a list of (n,2) arrays, where n is the number of points in the segment.
        n (int): number of points to resample the segment to. Defaults to 1000

    Returns:
        segments (list): the resampled segments.
    """
    for i, s in enumerate(segments):
        s = np.concatenate((s, s[0:1, :]), axis=0)
        x = np.linspace(0, len(s) - 1, n)
        xp = np.arange(len(s))
        segments[i] = (
            np.concatenate([np.interp(x, xp, s[:, i]) for i in range(2)], dtype=np.float32).reshape(2, -1).T
        )  # segment xy
    return segments



ultralytics.utils.ops.crop_mask(masks, boxes)

It takes a mask and a bounding box, and returns a mask that is cropped to the bounding box.

Parameters:

Name Type Description Default
masks Tensor

[n, h, w] tensor of masks

required
boxes Tensor

[n, 4] tensor of bbox coordinates in relative point form

required

Returns:

Type Description
Tensor

The masks are being cropped to the bounding box.

Source code in ultralytics/utils/ops.py
def crop_mask(masks, boxes):
    """
    It takes a mask and a bounding box, and returns a mask that is cropped to the bounding box.

    Args:
        masks (torch.Tensor): [n, h, w] tensor of masks
        boxes (torch.Tensor): [n, 4] tensor of bbox coordinates in relative point form

    Returns:
        (torch.Tensor): The masks are being cropped to the bounding box.
    """
    _, h, w = masks.shape
    x1, y1, x2, y2 = torch.chunk(boxes[:, :, None], 4, 1)  # x1 shape(n,1,1)
    r = torch.arange(w, device=masks.device, dtype=x1.dtype)[None, None, :]  # rows shape(1,1,w)
    c = torch.arange(h, device=masks.device, dtype=x1.dtype)[None, :, None]  # cols shape(1,h,1)

    return masks * ((r >= x1) * (r < x2) * (c >= y1) * (c < y2))



ultralytics.utils.ops.process_mask_upsample(protos, masks_in, bboxes, shape)

Takes the output of the mask head, and applies the mask to the bounding boxes. This produces masks of higher quality but is slower.

Parameters:

Name Type Description Default
protos Tensor

[mask_dim, mask_h, mask_w]

required
masks_in Tensor

[n, mask_dim], n is number of masks after nms

required
bboxes Tensor

[n, 4], n is number of masks after nms

required
shape tuple

the size of the input image (h,w)

required

Returns:

Type Description
Tensor

The upsampled masks.

Source code in ultralytics/utils/ops.py
def process_mask_upsample(protos, masks_in, bboxes, shape):
    """
    Takes the output of the mask head, and applies the mask to the bounding boxes. This produces masks of higher quality
    but is slower.

    Args:
        protos (torch.Tensor): [mask_dim, mask_h, mask_w]
        masks_in (torch.Tensor): [n, mask_dim], n is number of masks after nms
        bboxes (torch.Tensor): [n, 4], n is number of masks after nms
        shape (tuple): the size of the input image (h,w)

    Returns:
        (torch.Tensor): The upsampled masks.
    """
    c, mh, mw = protos.shape  # CHW
    masks = (masks_in @ protos.float().view(c, -1)).sigmoid().view(-1, mh, mw)
    masks = F.interpolate(masks[None], shape, mode="bilinear", align_corners=False)[0]  # CHW
    masks = crop_mask(masks, bboxes)  # CHW
    return masks.gt_(0.5)



ultralytics.utils.ops.process_mask(protos, masks_in, bboxes, shape, upsample=False)

Apply masks to bounding boxes using the output of the mask head.

Parameters:

Name Type Description Default
protos Tensor

A tensor of shape [mask_dim, mask_h, mask_w].

required
masks_in Tensor

A tensor of shape [n, mask_dim], where n is the number of masks after NMS.

required
bboxes Tensor

A tensor of shape [n, 4], where n is the number of masks after NMS.

required
shape tuple

A tuple of integers representing the size of the input image in the format (h, w).

required
upsample bool

A flag to indicate whether to upsample the mask to the original image size. Default is False.

False

Returns:

Type Description
Tensor

A binary mask tensor of shape [n, h, w], where n is the number of masks after NMS, and h and w are the height and width of the input image. The mask is applied to the bounding boxes.

Source code in ultralytics/utils/ops.py
def process_mask(protos, masks_in, bboxes, shape, upsample=False):
    """
    Apply masks to bounding boxes using the output of the mask head.

    Args:
        protos (torch.Tensor): A tensor of shape [mask_dim, mask_h, mask_w].
        masks_in (torch.Tensor): A tensor of shape [n, mask_dim], where n is the number of masks after NMS.
        bboxes (torch.Tensor): A tensor of shape [n, 4], where n is the number of masks after NMS.
        shape (tuple): A tuple of integers representing the size of the input image in the format (h, w).
        upsample (bool): A flag to indicate whether to upsample the mask to the original image size. Default is False.

    Returns:
        (torch.Tensor): A binary mask tensor of shape [n, h, w], where n is the number of masks after NMS, and h and w
            are the height and width of the input image. The mask is applied to the bounding boxes.
    """

    c, mh, mw = protos.shape  # CHW
    ih, iw = shape
    masks = (masks_in @ protos.float().view(c, -1)).sigmoid().view(-1, mh, mw)  # CHW
    width_ratio = mw / iw
    height_ratio = mh / ih

    downsampled_bboxes = bboxes.clone()
    downsampled_bboxes[:, 0] *= width_ratio
    downsampled_bboxes[:, 2] *= width_ratio
    downsampled_bboxes[:, 3] *= height_ratio
    downsampled_bboxes[:, 1] *= height_ratio

    masks = crop_mask(masks, downsampled_bboxes)  # CHW
    if upsample:
        masks = F.interpolate(masks[None], shape, mode="bilinear", align_corners=False)[0]  # CHW
    return masks.gt_(0.5)



ultralytics.utils.ops.process_mask_native(protos, masks_in, bboxes, shape)

It takes the output of the mask head, and crops it after upsampling to the bounding boxes.

Parameters:

Name Type Description Default
protos Tensor

[mask_dim, mask_h, mask_w]

required
masks_in Tensor

[n, mask_dim], n is number of masks after nms

required
bboxes Tensor

[n, 4], n is number of masks after nms

required
shape tuple

the size of the input image (h,w)

required

Returns:

Name Type Description
masks Tensor

The returned masks with dimensions [h, w, n]

Source code in ultralytics/utils/ops.py
def process_mask_native(protos, masks_in, bboxes, shape):
    """
    It takes the output of the mask head, and crops it after upsampling to the bounding boxes.

    Args:
        protos (torch.Tensor): [mask_dim, mask_h, mask_w]
        masks_in (torch.Tensor): [n, mask_dim], n is number of masks after nms
        bboxes (torch.Tensor): [n, 4], n is number of masks after nms
        shape (tuple): the size of the input image (h,w)

    Returns:
        masks (torch.Tensor): The returned masks with dimensions [h, w, n]
    """
    c, mh, mw = protos.shape  # CHW
    masks = (masks_in @ protos.float().view(c, -1)).sigmoid().view(-1, mh, mw)
    masks = scale_masks(masks[None], shape)[0]  # CHW
    masks = crop_mask(masks, bboxes)  # CHW
    return masks.gt_(0.5)



ultralytics.utils.ops.scale_masks(masks, shape, padding=True)

Rescale segment masks to shape.

Parameters:

Name Type Description Default
masks Tensor

(N, C, H, W).

required
shape tuple

Height and width.

required
padding bool

If True, assuming the boxes is based on image augmented by yolo style. If False then do regular rescaling.

True
Source code in ultralytics/utils/ops.py
def scale_masks(masks, shape, padding=True):
    """
    Rescale segment masks to shape.

    Args:
        masks (torch.Tensor): (N, C, H, W).
        shape (tuple): Height and width.
        padding (bool): If True, assuming the boxes is based on image augmented by yolo style. If False then do regular
            rescaling.
    """
    mh, mw = masks.shape[2:]
    gain = min(mh / shape[0], mw / shape[1])  # gain  = old / new
    pad = [mw - shape[1] * gain, mh - shape[0] * gain]  # wh padding
    if padding:
        pad[0] /= 2
        pad[1] /= 2
    top, left = (int(pad[1]), int(pad[0])) if padding else (0, 0)  # y, x
    bottom, right = (int(mh - pad[1]), int(mw - pad[0]))
    masks = masks[..., top:bottom, left:right]

    masks = F.interpolate(masks, shape, mode="bilinear", align_corners=False)  # NCHW
    return masks



ultralytics.utils.ops.scale_coords(img1_shape, coords, img0_shape, ratio_pad=None, normalize=False, padding=True)

Rescale segment coordinates (xy) from img1_shape to img0_shape.

Parameters:

Name Type Description Default
img1_shape tuple

The shape of the image that the coords are from.

required
coords Tensor

the coords to be scaled of shape n,2.

required
img0_shape tuple

the shape of the image that the segmentation is being applied to.

required
ratio_pad tuple

the ratio of the image size to the padded image size.

None
normalize bool

If True, the coordinates will be normalized to the range [0, 1]. Defaults to False.

False
padding bool

If True, assuming the boxes is based on image augmented by yolo style. If False then do regular rescaling.

True

Returns:

Name Type Description
coords Tensor

The scaled coordinates.

Source code in ultralytics/utils/ops.py
def scale_coords(img1_shape, coords, img0_shape, ratio_pad=None, normalize=False, padding=True):
    """
    Rescale segment coordinates (xy) from img1_shape to img0_shape.

    Args:
        img1_shape (tuple): The shape of the image that the coords are from.
        coords (torch.Tensor): the coords to be scaled of shape n,2.
        img0_shape (tuple): the shape of the image that the segmentation is being applied to.
        ratio_pad (tuple): the ratio of the image size to the padded image size.
        normalize (bool): If True, the coordinates will be normalized to the range [0, 1]. Defaults to False.
        padding (bool): If True, assuming the boxes is based on image augmented by yolo style. If False then do regular
            rescaling.

    Returns:
        coords (torch.Tensor): The scaled coordinates.
    """
    if ratio_pad is None:  # calculate from img0_shape
        gain = min(img1_shape[0] / img0_shape[0], img1_shape[1] / img0_shape[1])  # gain  = old / new
        pad = (img1_shape[1] - img0_shape[1] * gain) / 2, (img1_shape[0] - img0_shape[0] * gain) / 2  # wh padding
    else:
        gain = ratio_pad[0][0]
        pad = ratio_pad[1]

    if padding:
        coords[..., 0] -= pad[0]  # x padding
        coords[..., 1] -= pad[1]  # y padding
    coords[..., 0] /= gain
    coords[..., 1] /= gain
    coords = clip_coords(coords, img0_shape)
    if normalize:
        coords[..., 0] /= img0_shape[1]  # width
        coords[..., 1] /= img0_shape[0]  # height
    return coords



ultralytics.utils.ops.regularize_rboxes(rboxes)

Regularize rotated boxes in range [0, pi/2].

Parameters:

Name Type Description Default
rboxes Tensor

(N, 5), xywhr.

required

Returns:

Type Description
Tensor

The regularized boxes.

Source code in ultralytics/utils/ops.py
def regularize_rboxes(rboxes):
    """
    Regularize rotated boxes in range [0, pi/2].

    Args:
        rboxes (torch.Tensor): (N, 5), xywhr.

    Returns:
        (torch.Tensor): The regularized boxes.
    """
    x, y, w, h, t = rboxes.unbind(dim=-1)
    # Swap edge and angle if h >= w
    w_ = torch.where(w > h, w, h)
    h_ = torch.where(w > h, h, w)
    t = torch.where(w > h, t, t + math.pi / 2) % math.pi
    return torch.stack([x, y, w_, h_, t], dim=-1)  # regularized boxes



ultralytics.utils.ops.masks2segments(masks, strategy='largest')

It takes a list of masks(n,h,w) and returns a list of segments(n,xy)

Parameters:

Name Type Description Default
masks Tensor

the output of the model, which is a tensor of shape (batch_size, 160, 160)

required
strategy str

'concat' or 'largest'. Defaults to largest

'largest'

Returns:

Name Type Description
segments List

list of segment masks

Source code in ultralytics/utils/ops.py
def masks2segments(masks, strategy="largest"):
    """
    It takes a list of masks(n,h,w) and returns a list of segments(n,xy)

    Args:
        masks (torch.Tensor): the output of the model, which is a tensor of shape (batch_size, 160, 160)
        strategy (str): 'concat' or 'largest'. Defaults to largest

    Returns:
        segments (List): list of segment masks
    """
    segments = []
    for x in masks.int().cpu().numpy().astype("uint8"):
        c = cv2.findContours(x, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)[0]
        if c:
            if strategy == "concat":  # concatenate all segments
                c = np.concatenate([x.reshape(-1, 2) for x in c])
            elif strategy == "largest":  # select largest segment
                c = np.array(c[np.array([len(x) for x in c]).argmax()]).reshape(-1, 2)
        else:
            c = np.zeros((0, 2))  # no segments found
        segments.append(c.astype("float32"))
    return segments



ultralytics.utils.ops.convert_torch2numpy_batch(batch)

Convert a batch of FP32 torch tensors (0.0-1.0) to a NumPy uint8 array (0-255), changing from BCHW to BHWC layout.

Parameters:

Name Type Description Default
batch Tensor

Input tensor batch of shape (Batch, Channels, Height, Width) and dtype torch.float32.

required

Returns:

Type Description
ndarray

Output NumPy array batch of shape (Batch, Height, Width, Channels) and dtype uint8.

Source code in ultralytics/utils/ops.py
def convert_torch2numpy_batch(batch: torch.Tensor) -> np.ndarray:
    """
    Convert a batch of FP32 torch tensors (0.0-1.0) to a NumPy uint8 array (0-255), changing from BCHW to BHWC layout.

    Args:
        batch (torch.Tensor): Input tensor batch of shape (Batch, Channels, Height, Width) and dtype torch.float32.

    Returns:
        (np.ndarray): Output NumPy array batch of shape (Batch, Height, Width, Channels) and dtype uint8.
    """
    return (batch.permute(0, 2, 3, 1).contiguous() * 255).clamp(0, 255).to(torch.uint8).cpu().numpy()



ultralytics.utils.ops.clean_str(s)

Cleans a string by replacing special characters with underscore _

Parameters:

Name Type Description Default
s str

a string needing special characters replaced

required

Returns:

Type Description
str

a string with special characters replaced by an underscore _

Source code in ultralytics/utils/ops.py
def clean_str(s):
    """
    Cleans a string by replacing special characters with underscore _

    Args:
        s (str): a string needing special characters replaced

    Returns:
        (str): a string with special characters replaced by an underscore _
    """
    return re.sub(pattern="[|@#!ยกยท$โ‚ฌ%&()=?ยฟ^*;:,ยจยด><+]", repl="_", string=s)





Created 2023-11-12, Updated 2024-01-23
Authors: Laughing-q (1), glenn-jocher (4)