import mmcv
import numpy as np
from mmcv.utils import deprecated_api_warning, is_tuple_of
from numpy import random
from mmseg.datasets.builder import PIPELINES
from IPython import embed
@PIPELINES.register_module()
class AlignResize(object):
"""Resize images & seg. Align
"""
def __init__(self,
img_scale=None,
multiscale_mode='range',
ratio_range=None,
keep_ratio=True,
size_divisor=32):
if img_scale is None:
self.img_scale = None
else:
if isinstance(img_scale, list):
self.img_scale = img_scale
else:
self.img_scale = [img_scale]
assert mmcv.is_list_of(self.img_scale, tuple)
if ratio_range is not None:
# mode 1: given img_scale=None and a range of image ratio
# mode 2: given a scale and a range of image ratio
assert self.img_scale is None or len(self.img_scale) == 1
else:
# mode 3 and 4: given multiple scales or a range of scales
assert multiscale_mode in ['value', 'range']
self.multiscale_mode = multiscale_mode
self.ratio_range = ratio_range
self.keep_ratio = keep_ratio
self.size_divisor = size_divisor
@staticmethod
def random_select(img_scales):
"""Randomly select an img_scale from given candidates.
Args:
img_scales (list[tuple]): Images scales for selection.
Returns:
(tuple, int): Returns a tuple ``(img_scale, scale_dix)``,
where ``img_scale`` is the selected image scale and
``scale_idx`` is the selected index in the given candidates.
"""
assert mmcv.is_list_of(img_scales, tuple)
scale_idx = np.random.randint(len(img_scales))
img_scale = img_scales[scale_idx]
return img_scale, scale_idx
@staticmethod
def random_sample(img_scales):
"""Randomly sample an img_scale when ``multiscale_mode=='range'``.
Args:
img_scales (list[tuple]): Images scale range for sampling.
There must be two tuples in img_scales, which specify the lower
and uper bound of image scales.
Returns:
(tuple, None): Returns a tuple ``(img_scale, None)``, where
``img_scale`` is sampled scale and None is just a placeholder
to be consistent with :func:`random_select`.
"""
assert mmcv.is_list_of(img_scales, tuple) and len(img_scales) == 2
img_scale_long = [max(s) for s in img_scales]
img_scale_short = [min(s) for s in img_scales]
long_edge = np.random.randint(
min(img_scale_long),
max(img_scale_long) + 1)
short_edge = np.random.randint(
min(img_scale_short),
max(img_scale_short) + 1)
img_scale = (long_edge, short_edge)
return img_scale, None
@staticmethod
def random_sample_ratio(img_scale, ratio_range):
"""Randomly sample an img_scale when ``ratio_range`` is specified.
A ratio will be randomly sampled from the range specified by
``ratio_range``. Then it would be multiplied with ``img_scale`` to
generate sampled scale.
Args:
img_scale (tuple): Images scale base to multiply with ratio.
ratio_range (tuple[float]): The minimum and maximum ratio to scale
the ``img_scale``.
Returns:
(tuple, None): Returns a tuple ``(scale, None)``, where
``scale`` is sampled ratio multiplied with ``img_scale`` and
None is just a placeholder to be consistent with
:func:`random_select`.
"""
assert isinstance(img_scale, tuple) and len(img_scale) == 2
min_ratio, max_ratio = ratio_range
assert min_ratio <= max_ratio
ratio = np.random.random_sample() * (max_ratio - min_ratio) + min_ratio
scale = int(img_scale[0] * ratio), int(img_scale[1] * ratio)
return scale, None
def _random_scale(self, results):
"""Randomly sample an img_scale according to ``ratio_range`` and
``multiscale_mode``.
If ``ratio_range`` is specified, a ratio will be sampled and be
multiplied with ``img_scale``.
If multiple scales are specified by ``img_scale``, a scale will be
sampled according to ``multiscale_mode``.
Otherwise, single scale will be used.
Args:
results (dict): Result dict from :obj:`dataset`.
Returns:
dict: Two new keys 'scale` and 'scale_idx` are added into
``results``, which would be used by subsequent pipelines.
"""
if self.ratio_range is not None:
if self.img_scale is None:
h, w = results['img'].shape[:2]
scale, scale_idx = self.random_sample_ratio((w, h),
self.ratio_range)
else:
scale, scale_idx = self.random_sample_ratio(
self.img_scale[0], self.ratio_range)
elif len(self.img_scale) == 1:
scale, scale_idx = self.img_scale[0], 0
elif self.multiscale_mode == 'range':
scale, scale_idx = self.random_sample(self.img_scale)
elif self.multiscale_mode == 'value':
scale, scale_idx = self.random_select(self.img_scale)
else:
raise NotImplementedError
results['scale'] = scale
results['scale_idx'] = scale_idx
def _align(self, img, size_divisor, interpolation=None):
align_h = int(np.ceil(img.shape[0] / size_divisor)) * size_divisor
align_w = int(np.ceil(img.shape[1] / size_divisor)) * size_divisor
if interpolation == None:
img = mmcv.imresize(img, (align_w, align_h))
else:
img = mmcv.imresize(img, (align_w, align_h), interpolation=interpolation)
return img
def _resize_img(self, results):
"""Resize images with ``results['scale']``."""
if self.keep_ratio:
img, scale_factor = mmcv.imrescale(
results['img'], results['scale'], return_scale=True)
#### align ####
img = self._align(img, self.size_divisor)
# the w_scale and h_scale has minor difference
# a real fix should be done in the mmcv.imrescale in the future
new_h, new_w = img.shape[:2]
h, w = results['img'].shape[:2]
w_scale = new_w / w
h_scale = new_h / h
else:
img, w_scale, h_scale = mmcv.imresize(
results['img'], results['scale'], return_scale=True)
h, w = img.shape[:2]
assert int(np.ceil(h / self.size_divisor)) * self.size_divisor == h and \
int(np.ceil(w / self.size_divisor)) * self.size_divisor == w, \
"img size not align. h:{} w:{}".format(h,w)
scale_factor = np.array([w_scale, h_scale, w_scale, h_scale],
dtype=np.float32)
results['img'] = img
results['img_shape'] = img.shape
results['pad_shape'] = img.shape # in case that there is no padding
results['scale_factor'] = scale_factor
results['keep_ratio'] = self.keep_ratio
def _resize_seg(self, results):
"""Resize semantic segmentation map with ``results['scale']``."""
for key in results.get('seg_fields', []):
if self.keep_ratio:
gt_seg = mmcv.imrescale(
results[key], results['scale'], interpolation='nearest')
gt_seg = self._align(gt_seg, self.size_divisor, interpolation='nearest')
else:
gt_seg = mmcv.imresize(
results[key], results['scale'], interpolation='nearest')
h, w = gt_seg.shape[:2]
assert int(np.ceil(h / self.size_divisor)) * self.size_divisor == h and \
int(np.ceil(w / self.size_divisor)) * self.size_divisor == w, \
"gt_seg size not align. h:{} w:{}".format(h, w)
results[key] = gt_seg
def __call__(self, results):
"""Call function to resize images, bounding boxes, masks, semantic
segmentation map.
Args:
results (dict): Result dict from loading pipeline.
Returns:
dict: Resized results, 'img_shape', 'pad_shape', 'scale_factor',
'keep_ratio' keys are added into result dict.
"""
if 'scale' not in results:
self._random_scale(results)
self._resize_img(results)
self._resize_seg(results)
return results
def __repr__(self):
repr_str = self.__class__.__name__
repr_str += (f'(img_scale={self.img_scale}, '
f'multiscale_mode={self.multiscale_mode}, '
f'ratio_range={self.ratio_range}, '
f'keep_ratio={self.keep_ratio})')
return repr_str