Apply the resizing transform on rotated boxes. For details of how these (approximation)
formulas are derived, please refer to :meth:`RotatedBoxes.scale`.
Args:
rotated_boxes (ndarray): Nx5 floating point array of
(x_center, y_center, width, height, angle_degrees) format
in absolute coordinates.
"""
scale_factor_x = transform.new_w * 1.0 / transform.w
scale_factor_y = transform.new_h * 1.0 / transform.h
rotated_boxes[:, 0] *= scale_factor_x
rotated_boxes[:, 1] *= scale_factor_y
theta = rotated_boxes[:, 4] * np.pi / 180.0
c = np.cos(theta)
s = np.sin(theta)
rotated_boxes[:, 2] *= np.sqrt(
np.square(scale_factor_x * c) + np.square(scale_factor_y * s))
rotated_boxes[:, 3] *= np.sqrt(
np.square(scale_factor_x * s) + np.square(scale_factor_y * c))
rotated_boxes[:, 4] = np.arctan2(scale_factor_x * s,
scale_factor_y * c) * 180 / np.pi
return rotated_boxes
HFlipTransform.register_type("rotated_box", HFlip_rotated_box)
ResizeTransform.register_type("rotated_box", Resize_rotated_box)
# not necessary any more with latest fvcore
NoOpTransform.register_type("rotated_box", lambda t, x: x)
def Resize_rotated_box(transform, rotated_boxes):
"""
Apply the resizing transform on rotated boxes. For details of how these (approximation)
formulas are derived, please refer to :meth:`RotatedBoxes.scale`.
Args:
rotated_boxes (ndarray): Nx5 floating point array of
(x_center, y_center, width, height, angle_degrees) format
in absolute coordinates.
"""
rotated_boxes = np.asarray(rotated_boxes).reshape(-1, 5)
scale_factor_x = transform.new_w * 1.0 / transform.w
scale_factor_y = transform.new_h * 1.0 / transform.h
rotated_boxes[:, 0] *= scale_factor_x
rotated_boxes[:, 1] *= scale_factor_y
theta = rotated_boxes[:, 4] * np.pi / 180.0
c = np.cos(theta)
s = np.sin(theta)
rotated_boxes[:, 2] *= np.sqrt(np.square(scale_factor_x * c) + np.square(scale_factor_y * s))
rotated_boxes[:, 3] *= np.sqrt(np.square(scale_factor_x * s) + np.square(scale_factor_y * c))
rotated_boxes[:, 4] = np.arctan2(scale_factor_x * s, scale_factor_y * c) * 180 / np.pi
return rotated_boxes
HFlipTransform.register_type("rotated_box", HFlip_rotated_box)
VFlipTransform.register_type("rotated_box", VFlip_rotated_box)
# NoOpTransform.register_type("rotated_box", lambda t, x: x)
NoOpTransform.register_type("rotated_box", NoOp_rotated_box)
ResizeTransform.register_type("rotated_box", Resize_rotated_box)
