def graph_fn():
scales = [0.5, 1.0, 2.0]
aspect_ratios = [0.25, 1.0, 4.0]
anchor_offset = [7, -3]
anchor_generator = grid_anchor_generator.GridAnchorGenerator(
scales, aspect_ratios, anchor_offset=anchor_offset)
anchors_list = anchor_generator.generate(
feature_map_shape_list=[(1, 1)])
anchor_corners = anchors_list[0].get()
return anchor_corners,
def _generate(self, feature_map_shape_list, im_height, im_width):
"""Generates a collection of bounding boxes to be used as anchors.
Currently we require the input image shape to be statically defined. That
is, im_height and im_width should be integers rather than tensors.
Args:
feature_map_shape_list: list of pairs of convnet layer resolutions in the
format [(height_0, width_0), (height_1, width_1), ...]. For example,
setting feature_map_shape_list=[(8, 8), (7, 7)] asks for anchors that
correspond to an 8x8 layer followed by a 7x7 layer.
im_height: the height of the image to generate the grid for.
im_width: the width of the image to generate the grid for.
Returns:
boxes_list: a list of BoxLists each holding anchor boxes corresponding to
the input feature map shapes.
Raises:
ValueError: if im_height and im_width are not integers.
"""
if not isinstance(im_height, int) or not isinstance(im_width, int):
raise ValueError(
'MultiscaleGridAnchorGenerator currently requires '
'input image shape to be statically defined.')
anchor_grid_list = []
for feat_shape, grid_info in zip(feature_map_shape_list,
self._anchor_grid_info):
# TODO(rathodv) check the feature_map_shape_list is consistent with
# self._anchor_grid_info
level = grid_info['level']
stride = 2**level
scales, aspect_ratios, base_anchor_size, anchor_stride = grid_info[
'info']
feat_h = feat_shape[0]
feat_w = feat_shape[1]
anchor_offset = [0, 0]
if im_height % 2.0**level == 0:
anchor_offset[0] = stride / 2.0
if im_width % 2.0**level == 0:
anchor_offset[1] = stride / 2.0
ag = grid_anchor_generator.GridAnchorGenerator(
scales,
aspect_ratios,
base_anchor_size=base_anchor_size,
anchor_stride=anchor_stride,
anchor_offset=anchor_offset)
(anchor_grid, ) = ag.generate(feature_map_shape_list=[(feat_h,
feat_w)])
if self._normalize_coordinates:
anchor_grid = box_list_ops.to_normalized_coordinates(
anchor_grid, im_height, im_width, check_range=False)
anchor_grid_list.append(anchor_grid)
return anchor_grid_list
def graph_fn(feature_map_height, feature_map_width):
base_anchor_size = [10, 10]
anchor_stride = [19, 19]
anchor_offset = [0, 0]
scales = [0.5, 1.0, 2.0]
aspect_ratios = [1.0]
anchor_generator = grid_anchor_generator.GridAnchorGenerator(
scales,
aspect_ratios,
base_anchor_size=base_anchor_size,
anchor_stride=anchor_stride,
anchor_offset=anchor_offset)
anchors_list = anchor_generator.generate(
feature_map_shape_list=[(feature_map_height,
feature_map_width)])
anchor_corners = anchors_list[0].get()
return anchor_corners,
def build(anchor_generator_config):
"""Builds an anchor generator based on the config.
Args:
anchor_generator_config: An anchor_generator.proto object containing the
config for the desired anchor generator.
Returns:
Anchor generator based on the config.
Raises:
ValueError: On empty anchor generator proto.
"""
if False and not isinstance(anchor_generator_config,
anchor_generator_pb2.AnchorGenerator):
raise ValueError('anchor_generator_config not of type '
'anchor_generator_pb2.AnchorGenerator {0}'.format(
type(anchor_generator_config)))
if anchor_generator_config.WhichOneof(
'anchor_generator_oneof') == 'grid_anchor_generator':
grid_anchor_generator_config = anchor_generator_config.grid_anchor_generator
return grid_anchor_generator.GridAnchorGenerator(
scales=[
float(scale) for scale in grid_anchor_generator_config.scales
],
aspect_ratios=[
float(aspect_ratio)
for aspect_ratio in grid_anchor_generator_config.aspect_ratios
],
base_anchor_size=[
grid_anchor_generator_config.height,
grid_anchor_generator_config.width
],
anchor_stride=[
grid_anchor_generator_config.height_stride,
grid_anchor_generator_config.width_stride
],
anchor_offset=[
grid_anchor_generator_config.height_offset,
grid_anchor_generator_config.width_offset
])
elif anchor_generator_config.WhichOneof(
'anchor_generator_oneof') == 'ssd_anchor_generator':
ssd_anchor_generator_config = anchor_generator_config.ssd_anchor_generator
anchor_strides = None
if ssd_anchor_generator_config.height_stride:
anchor_strides = zip(ssd_anchor_generator_config.height_stride,
ssd_anchor_generator_config.width_stride)
anchor_offsets = None
if ssd_anchor_generator_config.height_offset:
anchor_offsets = zip(ssd_anchor_generator_config.height_offset,
ssd_anchor_generator_config.width_offset)
return multiple_grid_anchor_generator.create_ssd_anchors(
num_layers=ssd_anchor_generator_config.num_layers,
min_scale=ssd_anchor_generator_config.min_scale,
max_scale=ssd_anchor_generator_config.max_scale,
scales=[
float(scale) for scale in ssd_anchor_generator_config.scales
],
aspect_ratios=ssd_anchor_generator_config.aspect_ratios,
interpolated_scale_aspect_ratio=(
ssd_anchor_generator_config.interpolated_scale_aspect_ratio),
base_anchor_size=[
ssd_anchor_generator_config.base_anchor_height,
ssd_anchor_generator_config.base_anchor_width
],
anchor_strides=anchor_strides,
anchor_offsets=anchor_offsets,
reduce_boxes_in_lowest_layer=(
ssd_anchor_generator_config.reduce_boxes_in_lowest_layer))
elif anchor_generator_config.WhichOneof(
'anchor_generator_oneof') == 'multiscale_anchor_generator':
cfg = anchor_generator_config.multiscale_anchor_generator
return multiscale_grid_anchor_generator.MultiscaleGridAnchorGenerator(
cfg.min_level, cfg.max_level, cfg.anchor_scale,
[float(aspect_ratio) for aspect_ratio in cfg.aspect_ratios],
cfg.scales_per_octave, cfg.normalize_coordinates)
else:
raise ValueError('Empty anchor generator.')