official/legacy/detection/dataloader/maskrcnn_parser.py
# Copyright 2024 The TensorFlow Authors. All Rights Reserved.
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# Licensed under the Apache License, Version 2.0 (the "License");
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# http://www.apache.org/licenses/LICENSE-2.0
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"""Data parser and processing for Mask R-CNN."""
import tensorflow as tf, tf_keras
from official.legacy.detection.dataloader import anchor
from official.legacy.detection.dataloader import mode_keys as ModeKeys
from official.legacy.detection.dataloader import tf_example_decoder
from official.legacy.detection.utils import box_utils
from official.legacy.detection.utils import dataloader_utils
from official.legacy.detection.utils import input_utils
class Parser(object):
"""Parser to parse an image and its annotations into a dictionary of tensors."""
def __init__(self,
output_size,
min_level,
max_level,
num_scales,
aspect_ratios,
anchor_size,
rpn_match_threshold=0.7,
rpn_unmatched_threshold=0.3,
rpn_batch_size_per_im=256,
rpn_fg_fraction=0.5,
aug_rand_hflip=False,
aug_scale_min=1.0,
aug_scale_max=1.0,
skip_crowd_during_training=True,
max_num_instances=100,
include_mask=False,
mask_crop_size=112,
use_bfloat16=True,
mode=None):
"""Initializes parameters for parsing annotations in the dataset.
Args:
output_size: `Tensor` or `list` for [height, width] of output image. The
output_size should be divided by the largest feature stride 2^max_level.
min_level: `int` number of minimum level of the output feature pyramid.
max_level: `int` number of maximum level of the output feature pyramid.
num_scales: `int` number representing intermediate scales added
on each level. For instances, num_scales=2 adds one additional
intermediate anchor scales [2^0, 2^0.5] on each level.
aspect_ratios: `list` of float numbers representing the aspect raito
anchors added on each level. The number indicates the ratio of width to
height. For instances, aspect_ratios=[1.0, 2.0, 0.5] adds three anchors
on each scale level.
anchor_size: `float` number representing the scale of size of the base
anchor to the feature stride 2^level.
rpn_match_threshold:
rpn_unmatched_threshold:
rpn_batch_size_per_im:
rpn_fg_fraction:
aug_rand_hflip: `bool`, if True, augment training with random
horizontal flip.
aug_scale_min: `float`, the minimum scale applied to `output_size` for
data augmentation during training.
aug_scale_max: `float`, the maximum scale applied to `output_size` for
data augmentation during training.
skip_crowd_during_training: `bool`, if True, skip annotations labeled with
`is_crowd` equals to 1.
max_num_instances: `int` number of maximum number of instances in an
image. The groundtruth data will be padded to `max_num_instances`.
include_mask: a bool to indicate whether parse mask groundtruth.
mask_crop_size: the size which groundtruth mask is cropped to.
use_bfloat16: `bool`, if True, cast output image to tf.bfloat16.
mode: a ModeKeys. Specifies if this is training, evaluation, prediction
or prediction with groundtruths in the outputs.
"""
self._mode = mode
self._max_num_instances = max_num_instances
self._skip_crowd_during_training = skip_crowd_during_training
self._is_training = (mode == ModeKeys.TRAIN)
self._example_decoder = tf_example_decoder.TfExampleDecoder(
include_mask=include_mask)
# Anchor.
self._output_size = output_size
self._min_level = min_level
self._max_level = max_level
self._num_scales = num_scales
self._aspect_ratios = aspect_ratios
self._anchor_size = anchor_size
# Target assigning.
self._rpn_match_threshold = rpn_match_threshold
self._rpn_unmatched_threshold = rpn_unmatched_threshold
self._rpn_batch_size_per_im = rpn_batch_size_per_im
self._rpn_fg_fraction = rpn_fg_fraction
# Data augmentation.
self._aug_rand_hflip = aug_rand_hflip
self._aug_scale_min = aug_scale_min
self._aug_scale_max = aug_scale_max
# Mask.
self._include_mask = include_mask
self._mask_crop_size = mask_crop_size
# Device.
self._use_bfloat16 = use_bfloat16
# Data is parsed depending on the model Modekey.
if mode == ModeKeys.TRAIN:
self._parse_fn = self._parse_train_data
elif mode == ModeKeys.EVAL:
self._parse_fn = self._parse_eval_data
elif mode == ModeKeys.PREDICT or mode == ModeKeys.PREDICT_WITH_GT:
self._parse_fn = self._parse_predict_data
else:
raise ValueError('mode is not defined.')
def __call__(self, value):
"""Parses data to an image and associated training labels.
Args:
value: a string tensor holding a serialized tf.Example proto.
Returns:
image, labels: if mode == ModeKeys.TRAIN. see _parse_train_data.
{'images': image, 'labels': labels}: if mode == ModeKeys.PREDICT
or ModeKeys.PREDICT_WITH_GT.
"""
with tf.name_scope('parser'):
data = self._example_decoder.decode(value)
return self._parse_fn(data)
def _parse_train_data(self, data):
"""Parses data for training.
Args:
data: the decoded tensor dictionary from TfExampleDecoder.
Returns:
image: image tensor that is preproessed to have normalized value and
dimension [output_size[0], output_size[1], 3]
labels: a dictionary of tensors used for training. The following describes
{key: value} pairs in the dictionary.
image_info: a 2D `Tensor` that encodes the information of the image and
the applied preprocessing. It is in the format of
[[original_height, original_width], [scaled_height, scaled_width],
anchor_boxes: ordered dictionary with keys
[min_level, min_level+1, ..., max_level]. The values are tensor with
shape [height_l, width_l, 4] representing anchor boxes at each level.
rpn_score_targets: ordered dictionary with keys
[min_level, min_level+1, ..., max_level]. The values are tensor with
shape [height_l, width_l, anchors_per_location]. The height_l and
width_l represent the dimension of class logits at l-th level.
rpn_box_targets: ordered dictionary with keys
[min_level, min_level+1, ..., max_level]. The values are tensor with
shape [height_l, width_l, anchors_per_location * 4]. The height_l and
width_l represent the dimension of bounding box regression output at
l-th level.
gt_boxes: Groundtruth bounding box annotations. The box is represented
in [y1, x1, y2, x2] format. The coordinates are w.r.t the scaled
image that is fed to the network. The tennsor is padded with -1 to
the fixed dimension [self._max_num_instances, 4].
gt_classes: Groundtruth classes annotations. The tennsor is padded
with -1 to the fixed dimension [self._max_num_instances].
gt_masks: groundtrugh masks cropped by the bounding box and
resized to a fixed size determined by mask_crop_size.
"""
classes = data['groundtruth_classes']
boxes = data['groundtruth_boxes']
if self._include_mask:
masks = data['groundtruth_instance_masks']
is_crowds = data['groundtruth_is_crowd']
# Skips annotations with `is_crowd` = True.
if self._skip_crowd_during_training and self._is_training:
num_groundtruths = tf.shape(classes)[0]
with tf.control_dependencies([num_groundtruths, is_crowds]):
indices = tf.cond(
tf.greater(tf.size(is_crowds), 0),
lambda: tf.where(tf.logical_not(is_crowds))[:, 0],
lambda: tf.cast(tf.range(num_groundtruths), tf.int64))
classes = tf.gather(classes, indices)
boxes = tf.gather(boxes, indices)
if self._include_mask:
masks = tf.gather(masks, indices)
# Gets original image and its size.
image = data['image']
image_shape = tf.shape(image)[0:2]
# Normalizes image with mean and std pixel values.
image = input_utils.normalize_image(image)
# Flips image randomly during training.
if self._aug_rand_hflip:
if self._include_mask:
image, boxes, masks = input_utils.random_horizontal_flip(
image, boxes, masks)
else:
image, boxes = input_utils.random_horizontal_flip(
image, boxes)
# Converts boxes from normalized coordinates to pixel coordinates.
# Now the coordinates of boxes are w.r.t. the original image.
boxes = box_utils.denormalize_boxes(boxes, image_shape)
# Resizes and crops image.
image, image_info = input_utils.resize_and_crop_image(
image,
self._output_size,
padded_size=input_utils.compute_padded_size(
self._output_size, 2 ** self._max_level),
aug_scale_min=self._aug_scale_min,
aug_scale_max=self._aug_scale_max)
image_height, image_width, _ = image.get_shape().as_list()
# Resizes and crops boxes.
# Now the coordinates of boxes are w.r.t the scaled image.
image_scale = image_info[2, :]
offset = image_info[3, :]
boxes = input_utils.resize_and_crop_boxes(
boxes, image_scale, image_info[1, :], offset)
# Filters out ground truth boxes that are all zeros.
indices = box_utils.get_non_empty_box_indices(boxes)
boxes = tf.gather(boxes, indices)
classes = tf.gather(classes, indices)
if self._include_mask:
masks = tf.gather(masks, indices)
# Transfer boxes to the original image space and do normalization.
cropped_boxes = boxes + tf.tile(tf.expand_dims(offset, axis=0), [1, 2])
cropped_boxes /= tf.tile(tf.expand_dims(image_scale, axis=0), [1, 2])
cropped_boxes = box_utils.normalize_boxes(cropped_boxes, image_shape)
num_masks = tf.shape(masks)[0]
masks = tf.image.crop_and_resize(
tf.expand_dims(masks, axis=-1),
cropped_boxes,
box_indices=tf.range(num_masks, dtype=tf.int32),
crop_size=[self._mask_crop_size, self._mask_crop_size],
method='bilinear')
masks = tf.squeeze(masks, axis=-1)
# Assigns anchor targets.
# Note that after the target assignment, box targets are absolute pixel
# offsets w.r.t. the scaled image.
input_anchor = anchor.Anchor(
self._min_level,
self._max_level,
self._num_scales,
self._aspect_ratios,
self._anchor_size,
(image_height, image_width))
anchor_labeler = anchor.RpnAnchorLabeler(
input_anchor,
self._rpn_match_threshold,
self._rpn_unmatched_threshold,
self._rpn_batch_size_per_im,
self._rpn_fg_fraction)
rpn_score_targets, rpn_box_targets = anchor_labeler.label_anchors(
boxes, tf.cast(tf.expand_dims(classes, axis=-1), dtype=tf.float32))
# If bfloat16 is used, casts input image to tf.bfloat16.
if self._use_bfloat16:
image = tf.cast(image, dtype=tf.bfloat16)
inputs = {
'image': image,
'image_info': image_info,
}
# Packs labels for model_fn outputs.
labels = {
'anchor_boxes': input_anchor.multilevel_boxes,
'image_info': image_info,
'rpn_score_targets': rpn_score_targets,
'rpn_box_targets': rpn_box_targets,
}
inputs['gt_boxes'] = input_utils.pad_to_fixed_size(boxes,
self._max_num_instances,
-1)
inputs['gt_classes'] = input_utils.pad_to_fixed_size(
classes, self._max_num_instances, -1)
if self._include_mask:
inputs['gt_masks'] = input_utils.pad_to_fixed_size(
masks, self._max_num_instances, -1)
return inputs, labels
def _parse_eval_data(self, data):
"""Parses data for evaluation."""
raise NotImplementedError('Not implemented!')
def _parse_predict_data(self, data):
"""Parses data for prediction.
Args:
data: the decoded tensor dictionary from TfExampleDecoder.
Returns:
A dictionary of {'images': image, 'labels': labels} where
image: image tensor that is preproessed to have normalized value and
dimension [output_size[0], output_size[1], 3]
labels: a dictionary of tensors used for training. The following
describes {key: value} pairs in the dictionary.
source_ids: Source image id. Default value -1 if the source id is
empty in the groundtruth annotation.
image_info: a 2D `Tensor` that encodes the information of the image
and the applied preprocessing. It is in the format of
[[original_height, original_width], [scaled_height, scaled_width],
anchor_boxes: ordered dictionary with keys
[min_level, min_level+1, ..., max_level]. The values are tensor with
shape [height_l, width_l, 4] representing anchor boxes at each
level.
"""
# Gets original image and its size.
image = data['image']
image_shape = tf.shape(image)[0:2]
# Normalizes image with mean and std pixel values.
image = input_utils.normalize_image(image)
# Resizes and crops image.
image, image_info = input_utils.resize_and_crop_image(
image,
self._output_size,
padded_size=input_utils.compute_padded_size(
self._output_size, 2 ** self._max_level),
aug_scale_min=1.0,
aug_scale_max=1.0)
image_height, image_width, _ = image.get_shape().as_list()
# If bfloat16 is used, casts input image to tf.bfloat16.
if self._use_bfloat16:
image = tf.cast(image, dtype=tf.bfloat16)
# Compute Anchor boxes.
_ = anchor.Anchor(self._min_level, self._max_level, self._num_scales,
self._aspect_ratios, self._anchor_size,
(image_height, image_width))
labels = {
'image_info': image_info,
}
if self._mode == ModeKeys.PREDICT_WITH_GT:
# Converts boxes from normalized coordinates to pixel coordinates.
boxes = box_utils.denormalize_boxes(
data['groundtruth_boxes'], image_shape)
groundtruths = {
'source_id': data['source_id'],
'height': data['height'],
'width': data['width'],
'num_detections': tf.shape(data['groundtruth_classes']),
'boxes': boxes,
'classes': data['groundtruth_classes'],
'areas': data['groundtruth_area'],
'is_crowds': tf.cast(data['groundtruth_is_crowd'], tf.int32),
}
groundtruths['source_id'] = dataloader_utils.process_source_id(
groundtruths['source_id'])
groundtruths = dataloader_utils.pad_groundtruths_to_fixed_size(
groundtruths, self._max_num_instances)
# TODO(yeqing): Remove the `groundtrtuh` layer key (no longer needed).
labels['groundtruths'] = groundtruths
inputs = {
'image': image,
'image_info': image_info,
}
return inputs, labels