insecta / khandy /boxes /boxes_transform_flip.py
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import numpy as np
from .boxes_utils import assert_and_normalize_shape
def flip_boxes(boxes, x_center=0, y_center=0, direction='h'):
"""
Args:
boxes: (N, 4+K)
x_center: array-like whose shape is (), (1,), (N,), (1, 1) or (N, 1)
y_center: array-like whose shape is (), (1,), (N,), (1, 1) or (N, 1)
direction: str
"""
assert direction in ['x', 'h', 'horizontal',
'y', 'v', 'vertical',
'o', 'b', 'both']
boxes = np.asarray(boxes, np.float32)
ret_boxes = boxes.copy()
x_center = np.asarray(x_center, np.float32)
y_center = np.asarray(y_center, np.float32)
x_center = assert_and_normalize_shape(x_center, boxes.shape[0])
y_center = assert_and_normalize_shape(y_center, boxes.shape[0])
if direction in ['o', 'b', 'both', 'x', 'h', 'horizontal']:
ret_boxes[:, 0] = 2 * x_center - boxes[:, 2]
ret_boxes[:, 2] = 2 * x_center - boxes[:, 0]
if direction in ['o', 'b', 'both', 'y', 'v', 'vertical']:
ret_boxes[:, 1] = 2 * y_center - boxes[:, 3]
ret_boxes[:, 3] = 2 * y_center - boxes[:, 1]
return ret_boxes
def fliplr_boxes(boxes, x_center=0, y_center=0):
"""
Args:
boxes: (N, 4+K)
x_center: array-like whose shape is (), (1,), (N,), (1, 1) or (N, 1)
y_center: array-like whose shape is (), (1,), (N,), (1, 1) or (N, 1)
"""
boxes = np.asarray(boxes, np.float32)
ret_boxes = boxes.copy()
x_center = np.asarray(x_center, np.float32)
y_center = np.asarray(y_center, np.float32)
x_center = assert_and_normalize_shape(x_center, boxes.shape[0])
y_center = assert_and_normalize_shape(y_center, boxes.shape[0])
ret_boxes[:, 0] = 2 * x_center - boxes[:, 2]
ret_boxes[:, 2] = 2 * x_center - boxes[:, 0]
return ret_boxes
def flipud_boxes(boxes, x_center=0, y_center=0):
"""
Args:
boxes: (N, 4+K)
x_center: array-like whose shape is (), (1,), (N,), (1, 1) or (N, 1)
y_center: array-like whose shape is (), (1,), (N,), (1, 1) or (N, 1)
"""
boxes = np.asarray(boxes, np.float32)
ret_boxes = boxes.copy()
x_center = np.asarray(x_center, np.float32)
y_center = np.asarray(y_center, np.float32)
x_center = assert_and_normalize_shape(x_center, boxes.shape[0])
y_center = assert_and_normalize_shape(y_center, boxes.shape[0])
ret_boxes[:, 1] = 2 * y_center - boxes[:, 3]
ret_boxes[:, 3] = 2 * y_center - boxes[:, 1]
return ret_boxes
def transpose_boxes(boxes, x_center=0, y_center=0):
"""
Args:
boxes: (N, 4+K)
x_center: array-like whose shape is (), (1,), (N,), (1, 1) or (N, 1)
y_center: array-like whose shape is (), (1,), (N,), (1, 1) or (N, 1)
"""
boxes = np.asarray(boxes, np.float32)
ret_boxes = boxes.copy()
x_center = np.asarray(x_center, np.float32)
y_center = np.asarray(y_center, np.float32)
x_center = assert_and_normalize_shape(x_center, boxes.shape[0])
y_center = assert_and_normalize_shape(y_center, boxes.shape[0])
shift = x_center - y_center
ret_boxes[:, 0] = boxes[:, 1] + shift
ret_boxes[:, 1] = boxes[:, 0] - shift
ret_boxes[:, 2] = boxes[:, 3] + shift
ret_boxes[:, 3] = boxes[:, 2] - shift
return ret_boxes
def flip_boxes_in_image(boxes, image_width, image_height, direction='h'):
"""
Args:
boxes: (N, 4+K)
image_width: int
image_width: int
direction: str
References:
`core.bbox.bbox_flip` in mmdetection
`datasets.pipelines.RandomFlip.bbox_flip` in mmdetection
"""
x_center = (image_width - 1) * 0.5
y_center = (image_height - 1) * 0.5
ret_boxes = flip_boxes(boxes, x_center, y_center, direction=direction)
return ret_boxes
def rot90_boxes_in_image(boxes, image_width, image_height, n=1):
"""Rotate boxes counter-clockwise by 90 degrees.
References:
np.rot90
cv2.rotate
tf.image.rot90
"""
n = n % 4
if n == 0:
ret_boxes = boxes.copy()
elif n == 1:
ret_boxes = transpose_boxes(boxes)
ret_boxes = flip_boxes_in_image(ret_boxes, image_width, image_height, 'v')
elif n == 2:
ret_boxes = flip_boxes_in_image(boxes, image_width, image_height, 'o')
else:
ret_boxes = transpose_boxes(boxes)
ret_boxes = flip_boxes_in_image(ret_boxes, image_width, image_height, 'h');
return ret_boxes