def _shift_scale_aug(self, image, bbox, crop_bbox, size):
"""shift scale augmentation
Parameters
----------
image : np.array
image
bbox : list or np.array
bbox
crop_bbox :
crop size image from center
Return
image ,bbox after shift and scale
"""
im_h, im_w = image.shape[:2]
# adjust crop bounding box
crop_bbox_center = corner2center(crop_bbox)
if self.scale:
scale_x = (1.0 + SiamRPNaugmentation.random() * self.scale)
scale_y = (1.0 + SiamRPNaugmentation.random() * self.scale)
h, w = crop_bbox_center.h, crop_bbox_center.w
scale_x = min(scale_x, float(im_w) / w)
scale_y = min(scale_y, float(im_h) / h)
crop_bbox_center = Center(crop_bbox_center.x, crop_bbox_center.y,
crop_bbox_center.w * scale_x,
crop_bbox_center.h * scale_y)
crop_bbox = center2corner(crop_bbox_center)
if self.shift:
sx = SiamRPNaugmentation.random() * self.shift
sy = SiamRPNaugmentation.random() * self.shift
x1, y1, x2, y2 = crop_bbox
sx = max(-x1, min(im_w - 1 - x2, sx))
sy = max(-y1, min(im_h - 1 - y2, sy))
crop_bbox = Corner(x1 + sx, y1 + sy, x2 + sx, y2 + sy)
# adjust target bounding box
x1, y1 = crop_bbox.x1, crop_bbox.y1
bbox = Corner(bbox.x1 - x1, bbox.y1 - y1, bbox.x2 - x1, bbox.y2 - y1)
if self.scale:
bbox = Corner(bbox.x1 / scale_x, bbox.y1 / scale_y,
bbox.x2 / scale_x, bbox.y2 / scale_y)
image = self._crop_roi(image, crop_bbox, size)
return image, bbox
def _get_bbox(self, image, shape):
imh, imw = image.shape[:2]
if len(shape) == 4:
w, h = shape[2] - shape[0], shape[3] - shape[1]
else:
w, h = shape
context_amount = 0.5
exemplar_size = self.train_exemplar_size
wc_z = w + context_amount * (w + h)
hc_z = h + context_amount * (w + h)
s_z = np.sqrt(wc_z * hc_z)
scale_z = exemplar_size / s_z
w = w * scale_z
h = h * scale_z
cx, cy = imw // 2, imh // 2
bbox = center2corner(Center(cx, cy, w, h))
return bbox
def __call__(self, image, bbox, size, gray=False):
shape = image.shape
crop_bbox = center2corner(
Center(shape[0] // 2, shape[1] // 2, size - 1, size - 1))
# gray augmentation
if gray:
image = self._gray_aug(image)
# shift scale augmentation
image, bbox = self._shift_scale_aug(image, bbox, crop_bbox, size)
# color augmentation
if self.color > np.random.random():
image = self._color_aug(image)
# blur augmentation
if self.blur > np.random.random():
image = self._blur_aug(image)
# flip augmentation
if self.flip and self.flip > np.random.random():
image, bbox = self._flip_aug(image, bbox)
return image, bbox