Cleanup ops (#6024)

* Cleanup ops

* Address nits
Co-authored-by: Philip Meier <github.pmeier@posteo.de>
Co-authored-by: Vasilis Vryniotis <datumbox@users.noreply.github.com>

torchvision/ops/__init__.py

@@ -5,13 +5,13 @@ from .boxes import (
     remove_small_boxes,
     clip_boxes_to_image,
     box_area,
+    box_convert,
     box_iou,
     generalized_box_iou,
     distance_box_iou,
     complete_box_iou,
     masks_to_boxes,
 )
-from .boxes import box_convert
 from .ciou_loss import complete_box_iou_loss
 from .deform_conv import deform_conv2d, DeformConv2d
 from .diou_loss import distance_box_iou_loss

torchvision/ops/_utils.py

@@ -67,3 +67,40 @@ def split_normalization_params(
         else:
             other_params.extend(p for p in module.parameters() if p.requires_grad)
     return norm_params, other_params
+
+
+def _upcast(t: Tensor) -> Tensor:
+    # Protects from numerical overflows in multiplications by upcasting to the equivalent higher type
+    if t.is_floating_point():
+        return t if t.dtype in (torch.float32, torch.float64) else t.float()
+    else:
+        return t if t.dtype in (torch.int32, torch.int64) else t.int()
+
+
+def _upcast_non_float(t: Tensor) -> Tensor:
+    # Protects from numerical overflows in multiplications by upcasting to the equivalent higher type
+    if t.dtype not in (torch.float32, torch.float64):
+        return t.float()
+    return t
+
+
+def _loss_inter_union(
+    boxes1: torch.Tensor,
+    boxes2: torch.Tensor,
+) -> Tuple[torch.Tensor, torch.Tensor]:
+
+    x1, y1, x2, y2 = boxes1.unbind(dim=-1)
+    x1g, y1g, x2g, y2g = boxes2.unbind(dim=-1)
+
+    # Intersection keypoints
+    xkis1 = torch.max(x1, x1g)
+    ykis1 = torch.max(y1, y1g)
+    xkis2 = torch.min(x2, x2g)
+    ykis2 = torch.min(y2, y2g)
+
+    intsctk = torch.zeros_like(x1)
+    mask = (ykis2 > ykis1) & (xkis2 > xkis1)
+    intsctk[mask] = (xkis2[mask] - xkis1[mask]) * (ykis2[mask] - ykis1[mask])
+    unionk = (x2 - x1) * (y2 - y1) + (x2g - x1g) * (y2g - y1g) - intsctk
+
+    return intsctk, unionk

torchvision/ops/boxes.py

@@ -7,6 +7,7 @@ from torchvision.extension import _assert_has_ops
 
 from ..utils import _log_api_usage_once
 from ._box_convert import _box_cxcywh_to_xyxy, _box_xyxy_to_cxcywh, _box_xywh_to_xyxy, _box_xyxy_to_xywh
+from ._utils import _upcast
 
 
 def nms(boxes: Tensor, scores: Tensor, iou_threshold: float) -> Tensor:
@@ -215,14 +216,6 @@ def box_convert(boxes: Tensor, in_fmt: str, out_fmt: str) -> Tensor:
     return boxes
 
 
-def _upcast(t: Tensor) -> Tensor:
-    # Protects from numerical overflows in multiplications by upcasting to the equivalent higher type
-    if t.is_floating_point():
-        return t if t.dtype in (torch.float32, torch.float64) else t.float()
-    else:
-        return t if t.dtype in (torch.int32, torch.int64) else t.int()
-
-
 def box_area(boxes: Tensor) -> Tensor:
     """
     Computes the area of a set of bounding boxes, which are specified by their
@@ -330,22 +323,7 @@ def complete_box_iou(boxes1: Tensor, boxes2: Tensor, eps: float = 1e-7) -> Tenso
     boxes1 = _upcast(boxes1)
     boxes2 = _upcast(boxes2)
 
-    inter, union = _box_inter_union(boxes1, boxes2)
-    iou = inter / union
-
-    lti = torch.min(boxes1[:, None, :2], boxes2[:, None, :2])
-    rbi = torch.max(boxes1[:, None, 2:], boxes2[:, None, 2:])
-
-    whi = (rbi - lti).clamp(min=0)  # [N,M,2]
-    diagonal_distance_squared = (whi[:, :, 0] ** 2) + (whi[:, :, 1] ** 2) + eps
-
-    # centers of boxes
-    x_p = (boxes1[:, 0] + boxes1[:, 2]) / 2
-    y_p = (boxes1[:, 1] + boxes1[:, 3]) / 2
-    x_g = (boxes2[:, 0] + boxes2[:, 2]) / 2
-    y_g = (boxes2[:, 1] + boxes2[:, 3]) / 2
-    # The distance between boxes' centers squared.
-    centers_distance_squared = (x_p - x_g) ** 2 + (y_p - y_g) ** 2
+    diou, iou = _box_diou_iou(boxes1, boxes2, eps)
 
     w_pred = boxes1[:, 2] - boxes1[:, 0]
     h_pred = boxes1[:, 3] - boxes1[:, 1]
@@ -356,7 +334,7 @@ def complete_box_iou(boxes1: Tensor, boxes2: Tensor, eps: float = 1e-7) -> Tenso
     v = (4 / (torch.pi ** 2)) * torch.pow((torch.atan(w_gt / h_gt) - torch.atan(w_pred / h_pred)), 2)
     with torch.no_grad():
         alpha = v / (1 - iou + v + eps)
-    return iou - (centers_distance_squared / diagonal_distance_squared) - alpha * v
+    return diou - alpha * v
 
 
 def distance_box_iou(boxes1: Tensor, boxes2: Tensor, eps: float = 1e-7) -> Tensor:
@@ -380,16 +358,17 @@ def distance_box_iou(boxes1: Tensor, boxes2: Tensor, eps: float = 1e-7) -> Tenso
 
     boxes1 = _upcast(boxes1)
     boxes2 = _upcast(boxes2)
+    diou, _ = _box_diou_iou(boxes1, boxes2)
+    return diou
 
-    inter, union = _box_inter_union(boxes1, boxes2)
-    iou = inter / union
 
+def _box_diou_iou(boxes1: Tensor, boxes2: Tensor, eps: float = 1e-7) -> Tuple[Tensor, Tensor]:
+
+    iou = box_iou(boxes1, boxes2)
     lti = torch.min(boxes1[:, None, :2], boxes2[:, :2])
     rbi = torch.max(boxes1[:, None, 2:], boxes2[:, 2:])
-
     whi = _upcast(rbi - lti).clamp(min=0)  # [N,M,2]
     diagonal_distance_squared = (whi[:, :, 0] ** 2) + (whi[:, :, 1] ** 2) + eps
-
     # centers of boxes
     x_p = (boxes1[:, 0] + boxes1[:, 2]) / 2
     y_p = (boxes1[:, 1] + boxes1[:, 3]) / 2
@@ -397,10 +376,9 @@ def distance_box_iou(boxes1: Tensor, boxes2: Tensor, eps: float = 1e-7) -> Tenso
     y_g = (boxes2[:, 1] + boxes2[:, 3]) / 2
     # The distance between boxes' centers squared.
     centers_distance_squared = (_upcast(x_p - x_g) ** 2) + (_upcast(y_p - y_g) ** 2)
-
     # The distance IoU is the IoU penalized by a normalized
     # distance between boxes' centers squared.
-    return iou - (centers_distance_squared / diagonal_distance_squared)
+    return iou - (centers_distance_squared / diagonal_distance_squared), iou
 
 
 def masks_to_boxes(masks: torch.Tensor) -> torch.Tensor:

torchvision/ops/ciou_loss.py

 import torch
 
 from ..utils import _log_api_usage_once
-from .giou_loss import _upcast
+from ._utils import _upcast_non_float
+from .diou_loss import _diou_iou_loss
 
 
 def complete_box_iou_loss(
@@ -30,50 +31,28 @@ def complete_box_iou_loss(
             ``'sum'``: The output will be summed. Default: ``'none'``
         eps : (float): small number to prevent division by zero. Default: 1e-7
 
-    Reference:
+    Returns:
+        Tensor: Loss tensor with the reduction option applied.
 
-    Complete Intersection over Union Loss (Zhaohui Zheng et. al)
-    https://arxiv.org/abs/1911.08287
+    Reference:
+        Zhaohui Zheng et. al: Complete Intersection over Union Loss:
+        https://arxiv.org/abs/1911.08287
 
     """
 
-    # Original Implementation : https://github.com/facebookresearch/detectron2/blob/main/detectron2/layers/losses.py
+    # Original Implementation from https://github.com/facebookresearch/detectron2/blob/main/detectron2/layers/losses.py
 
     if not torch.jit.is_scripting() and not torch.jit.is_tracing():
         _log_api_usage_once(complete_box_iou_loss)
 
-    boxes1 = _upcast(boxes1)
-    boxes2 = _upcast(boxes2)
+    boxes1 = _upcast_non_float(boxes1)
+    boxes2 = _upcast_non_float(boxes2)
+
+    diou_loss, iou = _diou_iou_loss(boxes1, boxes2)
 
     x1, y1, x2, y2 = boxes1.unbind(dim=-1)
     x1g, y1g, x2g, y2g = boxes2.unbind(dim=-1)
 
-    # Intersection keypoints
-    xkis1 = torch.max(x1, x1g)
-    ykis1 = torch.max(y1, y1g)
-    xkis2 = torch.min(x2, x2g)
-    ykis2 = torch.min(y2, y2g)
-
-    intsct = torch.zeros_like(x1)
-    mask = (ykis2 > ykis1) & (xkis2 > xkis1)
-    intsct[mask] = (xkis2[mask] - xkis1[mask]) * (ykis2[mask] - ykis1[mask])
-    union = (x2 - x1) * (y2 - y1) + (x2g - x1g) * (y2g - y1g) - intsct + eps
-    iou = intsct / union
-
-    # smallest enclosing box
-    xc1 = torch.min(x1, x1g)
-    yc1 = torch.min(y1, y1g)
-    xc2 = torch.max(x2, x2g)
-    yc2 = torch.max(y2, y2g)
-    diag_len = ((xc2 - xc1) ** 2) + ((yc2 - yc1) ** 2) + eps
-
-    # centers of boxes
-    x_p = (x2 + x1) / 2
-    y_p = (y2 + y1) / 2
-    x_g = (x1g + x2g) / 2
-    y_g = (y1g + y2g) / 2
-    distance = ((x_p - x_g) ** 2) + ((y_p - y_g) ** 2)
-
     # width and height of boxes
     w_pred = x2 - x1
     h_pred = y2 - y1
@@ -83,7 +62,7 @@ def complete_box_iou_loss(
     with torch.no_grad():
         alpha = v / (1 - iou + v + eps)
 
-    loss = 1 - iou + (distance / diag_len) + alpha * v
+    loss = diou_loss + alpha * v
     if reduction == "mean":
         loss = loss.mean() if loss.numel() > 0 else 0.0 * loss.sum()
     elif reduction == "sum":

torchvision/ops/diou_loss.py

+from typing import Tuple
+
 import torch
 
 from ..utils import _log_api_usage_once
-from .boxes import _upcast
+from ._utils import _loss_inter_union, _upcast_non_float
 
 
 def distance_box_iou_loss(
@@ -10,6 +12,7 @@ def distance_box_iou_loss(
     reduction: str = "none",
     eps: float = 1e-7,
 ) -> torch.Tensor:
+
     """
     Gradient-friendly IoU loss with an additional penalty that is non-zero when the
     distance between boxes' centers isn't zero. Indeed, for two exactly overlapping
@@ -37,37 +40,40 @@ def distance_box_iou_loss(
         https://arxiv.org/abs/1911.08287
     """
 
-    # Original Implementation : https://github.com/facebookresearch/detectron2/blob/main/detectron2/layers/losses.py
+    # Original Implementation from https://github.com/facebookresearch/detectron2/blob/main/detectron2/layers/losses.py
 
     if not torch.jit.is_scripting() and not torch.jit.is_tracing():
         _log_api_usage_once(distance_box_iou_loss)
 
-    boxes1 = _upcast(boxes1)
-    boxes2 = _upcast(boxes2)
+    boxes1 = _upcast_non_float(boxes1)
+    boxes2 = _upcast_non_float(boxes2)
 
-    x1, y1, x2, y2 = boxes1.unbind(dim=-1)
-    x1g, y1g, x2g, y2g = boxes2.unbind(dim=-1)
+    loss, _ = _diou_iou_loss(boxes1, boxes2, eps)
 
-    # Intersection keypoints
-    xkis1 = torch.max(x1, x1g)
-    ykis1 = torch.max(y1, y1g)
-    xkis2 = torch.min(x2, x2g)
-    ykis2 = torch.min(y2, y2g)
+    if reduction == "mean":
+        loss = loss.mean() if loss.numel() > 0 else 0.0 * loss.sum()
+    elif reduction == "sum":
+        loss = loss.sum()
+    return loss
 
-    intsct = torch.zeros_like(x1)
-    mask = (ykis2 > ykis1) & (xkis2 > xkis1)
-    intsct[mask] = (xkis2[mask] - xkis1[mask]) * (ykis2[mask] - ykis1[mask])
-    union = (x2 - x1) * (y2 - y1) + (x2g - x1g) * (y2g - y1g) - intsct + eps
-    iou = intsct / union
 
+def _diou_iou_loss(
+    boxes1: torch.Tensor,
+    boxes2: torch.Tensor,
+    eps: float = 1e-7,
+) -> Tuple[torch.Tensor, torch.Tensor]:
+
+    intsct, union = _loss_inter_union(boxes1, boxes2)
+    iou = intsct / (union + eps)
     # smallest enclosing box
+    x1, y1, x2, y2 = boxes1.unbind(dim=-1)
+    x1g, y1g, x2g, y2g = boxes2.unbind(dim=-1)
     xc1 = torch.min(x1, x1g)
     yc1 = torch.min(y1, y1g)
     xc2 = torch.max(x2, x2g)
     yc2 = torch.max(y2, y2g)
     # The diagonal distance of the smallest enclosing box squared
     diagonal_distance_squared = ((xc2 - xc1) ** 2) + ((yc2 - yc1) ** 2) + eps
-
     # centers of boxes
     x_p = (x2 + x1) / 2
     y_p = (y2 + y1) / 2
@@ -75,12 +81,7 @@ def distance_box_iou_loss(
     y_g = (y1g + y2g) / 2
     # The distance between boxes' centers squared.
     centers_distance_squared = ((x_p - x_g) ** 2) + ((y_p - y_g) ** 2)
-
     # The distance IoU is the IoU penalized by a normalized
     # distance between boxes' centers squared.
     loss = 1 - iou + (centers_distance_squared / diagonal_distance_squared)
-    if reduction == "mean":
-        loss = loss.mean() if loss.numel() > 0 else 0.0 * loss.sum()
-    elif reduction == "sum":
-        loss = loss.sum()
-    return loss
+    return loss, iou

torchvision/ops/giou_loss.py

 import torch
-from torch import Tensor
 
 from ..utils import _log_api_usage_once
-
-
-def _upcast(t: Tensor) -> Tensor:
-    # Protects from numerical overflows in multiplications by upcasting to the equivalent higher type
-    if t.dtype not in (torch.float32, torch.float64):
-        return t.float()
-    return t
+from ._utils import _upcast_non_float, _loss_inter_union
 
 
 def generalized_box_iou_loss(
@@ -17,10 +10,8 @@ def generalized_box_iou_loss(
     reduction: str = "none",
     eps: float = 1e-7,
 ) -> torch.Tensor:
-    """
-    Original implementation from
-    https://github.com/facebookresearch/fvcore/blob/bfff2ef/fvcore/nn/giou_loss.py
 
+    """
     Gradient-friendly IoU loss with an additional penalty that is non-zero when the
     boxes do not overlap and scales with the size of their smallest enclosing box.
     This loss is symmetric, so the boxes1 and boxes2 arguments are interchangeable.
@@ -38,31 +29,28 @@ def generalized_box_iou_loss(
             ``'sum'``: The output will be summed. Default: ``'none'``
         eps (float): small number to prevent division by zero. Default: 1e-7
 
+    Returns:
+        Tensor: Loss tensor with the reduction option applied.
+
     Reference:
         Hamid Rezatofighi et. al: Generalized Intersection over Union:
         A Metric and A Loss for Bounding Box Regression:
         https://arxiv.org/abs/1902.09630
     """
+
+    # Original implementation from https://github.com/facebookresearch/fvcore/blob/bfff2ef/fvcore/nn/giou_loss.py
+
     if not torch.jit.is_scripting() and not torch.jit.is_tracing():
         _log_api_usage_once(generalized_box_iou_loss)
 
-    boxes1 = _upcast(boxes1)
-    boxes2 = _upcast(boxes2)
+    boxes1 = _upcast_non_float(boxes1)
+    boxes2 = _upcast_non_float(boxes2)
+    intsctk, unionk = _loss_inter_union(boxes1, boxes2)
+    iouk = intsctk / (unionk + eps)
+
     x1, y1, x2, y2 = boxes1.unbind(dim=-1)
     x1g, y1g, x2g, y2g = boxes2.unbind(dim=-1)
 
-    # Intersection keypoints
-    xkis1 = torch.max(x1, x1g)
-    ykis1 = torch.max(y1, y1g)
-    xkis2 = torch.min(x2, x2g)
-    ykis2 = torch.min(y2, y2g)
-
-    intsctk = torch.zeros_like(x1)
-    mask = (ykis2 > ykis1) & (xkis2 > xkis1)
-    intsctk[mask] = (xkis2[mask] - xkis1[mask]) * (ykis2[mask] - ykis1[mask])
-    unionk = (x2 - x1) * (y2 - y1) + (x2g - x1g) * (y2g - y1g) - intsctk
-    iouk = intsctk / (unionk + eps)
-
     # smallest enclosing box
     xc1 = torch.min(x1, x1g)
     yc1 = torch.min(y1, y1g)