def next(self):
# 1) pick a random frame
frame = self.source[random.choice(self.frame_ids)]
# 2) generate a random perturbation and perturb the frame, this also perturbs the objects including segementation polygons
perturbed_frame = RandomPerturber.perturb_frame(frame, {})
# 3) scale the perturbed frame to the desired input resolution
crop_affine = resize_image_center_crop(perturbed_frame.image,
self.crop_size)
perturbed_frame = apply_affine_to_frame(perturbed_frame, crop_affine,
self.crop_size)
# visualize the perturbed_frame along with its perturbed objects and masks here
# perturbed_frame.visualize(display=True)
# 3) for each object type, produce a merged binary mask over the frame,
# this results in a w x h x k target map where k is the number of classes in consideration
# for now we will use the pycocotool's merge and polygon mapping functions since they are implemented in c
# although I prefer to not have this dependency
# loop over all object type and create a binary mask for each
# declare a np array of whk
masks = np.zeros(perturbed_frame.image.get_hw().tolist() +
[len(self.obj_types_to_ids)])
for k, v in self.obj_types_to_ids.items():
# a) for all objs in the frame that belong to this type, create a merged mask
polygons = []
for obj in perturbed_frame.get_objects():
if obj.obj_type == k:
polygons.extend(obj.polygons)
masks[:, :,
v] = Polygon.create_mask(polygons,
perturbed_frame.image.get_wh()[0],
perturbed_frame.image.get_wh()[1])
# 4) create the segmentation sample
chw_image = perturbed_frame.image.to_order_and_class(
Ordering.CHW, ValueClass.FLOAT01)
# transpose the mask
chw_mask = np.transpose(masks, axes=(2, 0, 1))
# chw_image.visualize(title='chw_image')
sample = SegmentationSample(
[torch.Tensor(chw_image.get_data().astype(float))],
[torch.Tensor(chw_mask)], self.ids_to_obj_types)
return sample
def __next__(self):
# 1) pick a random frame
frame = self.source[random.choice(self.frame_ids)]
# 2) generate a random perturbation and perturb the frame
perturb_params = {
'translation_range': [-0.1, 0.1],
'scaling_range': [0.9, 1.1]
}
perturbed_frame = RandomPerturber.perturb_frame(frame, perturb_params)
crop_affine = resize_image_center_crop(perturbed_frame.image,
self.crop_size)
output_size = [self.crop_size[1], self.crop_size[0]]
perturbed_frame = apply_affine_to_frame(perturbed_frame, crop_affine,
output_size)
# perturbed_frame.visualize(title='chw_image',display=True)
# 3) encode the objects into targets with size that does not exceed max_objects
# if there are more objects than max_objects, the remaining ones are dropped.
# vector of length max_objects
# each comp vector has the form [class(1),bbox(4)]
# a padding target is used to represent a non-existent object, this has the form [-1,-1,-1,-1,-1]
# create the padding vector
class_encoding, class_decoding = dict(), dict()
padvec = [np.array([-1] * 5) for i in range(self.max_objects)]
for i, obj in enumerate(perturbed_frame.objects[
0:min(self.max_objects, len(perturbed_frame.objects))]):
if obj.obj_type not in self.obj_types:
continue
if obj.obj_type not in class_encoding:
code = len(class_encoding)
class_encoding[obj.obj_type] = code
class_decoding[code] = obj.obj_type
box_coords = obj.box.to_single_array()
padvec[i] = np.concatenate(
(np.array([class_encoding[obj.obj_type]]), box_coords), axis=0)
chw_image = perturbed_frame.image.to_order_and_class(
Ordering.CHW, ValueClass.FLOAT01)
sample = MultiObjectDetectionSample(
[torch.Tensor(chw_image.get_data().astype(float))],
[torch.Tensor(padvec)], class_decoding)
return sample
def __next__(self):
# randomly pick 3 frames in a row
num_frames_in_src = len(self.source)
# print("Number of frames in src {}".format(num_frames_in_src))
# 1) choose the first frame from 0 -> N-2
frames = []
first_frame = random.randint(0, num_frames_in_src - self.num_frames)
for i in range(0, self.num_frames):
frames.append(self.source[first_frame + i])
# 2) generate a random perturbation and perturb all the frames
# note, need to apply same perts to all frames
perturb_params = {
'translation_range': [0.0, 0.0],
'scaling_range': [1.0, 1.0]
}
perturbed_frames = []
for f in frames:
perturbed_frame = RandomPerturber.perturb_frame(f, perturb_params)
crop_affine = resize_image_center_crop(perturbed_frame.image,
self.crop_size)
output_size = [self.crop_size[1], self.crop_size[0]]
perturbed_frame = apply_affine_to_frame(perturbed_frame,
crop_affine, output_size)
perturbed_frames.append(perturbed_frame)
# perturbed_frame.visualize(title='chw_image',display=True)
# 3) prepare tensors
# -make a tensor with a stack of 3 frame
# -add the calibration to the target
input_tensors = []
calib_mats = []
for f in perturbed_frames:
img = f.image.to_order_and_class(Ordering.CHW, ValueClass.FLOAT01)
input_tensors.append(torch.Tensor(img.get_data().astype(float)))
calib_mats.append(torch.Tensor(f.calib_mat))
# the input is now 3xCxWxH
sample = SequenceVideoSample([torch.stack(input_tensors, dim=0)],
[torch.stack(calib_mats)])
return sample