LXXXXR 8c11c01fdb
[Feature] Add shear pipeline (#163)
* half-done auto_augmentation

* remove auto_augcode and support shear pipeline

* fix typo

* fix typo

* use a non-square toy data instead
2021-02-25 16:00:46 +08:00

87 lines
3.6 KiB
Python

import mmcv
import numpy as np
from ..builder import PIPELINES
def random_negative(value, random_negative_prob):
"""Randomly negate value based on random_negative_prob."""
return -value if np.random.rand() < random_negative_prob else value
@PIPELINES.register_module()
class Shear(object):
"""Shear images.
Args:
magnitude (int | float): The magnitude used for shear.
pad_val (int, tuple[int]): Pixel pad_val value for constant fill. If a
tuple of length 3, it is used to pad_val R, G, B channels
respectively. Defaults to 128.
prob (float): The probability for performing Shear therefore should be
in range [0, 1]. Defaults to 0.5.
direction (str): The shearing direction. Options are 'horizontal' and
'vertical'. Defaults to 'horizontal'.
random_negative_prob (float): The probability that turns the magnitude
negative, which should be in range [0,1]. Defaults to 0.5.
interpolation (str): Interpolation method. Options are 'nearest',
'bilinear', 'bicubic', 'area', 'lanczos'. Defaults to 'bicubic'.
"""
def __init__(self,
magnitude,
pad_val=128,
prob=0.5,
direction='horizontal',
random_negative_prob=0.5,
interpolation='bicubic'):
assert isinstance(magnitude, (int, float)), 'The magnitude type must '\
f'be int or float, but got {type(magnitude)} instead.'
if isinstance(pad_val, int):
pad_val = tuple([pad_val] * 3)
elif isinstance(pad_val, tuple):
assert len(pad_val) == 3, 'pad_val as a tuple must have 3 ' \
f'elements, got {len(pad_val)} instead.'
assert all(isinstance(i, int) for i in pad_val), 'pad_val as a '\
'tuple must got elements of int type.'
else:
raise TypeError('pad_val must be int or tuple with 3 elements.')
assert 0 <= prob <= 1.0, 'The prob should be in range [0,1], ' \
f'got {prob} instead.'
assert direction in ('horizontal', 'vertical'), 'direction must be ' \
f'either "horizontal" or "vertical", got {direction} instead.'
assert 0 <= random_negative_prob <= 1.0, 'The random_negative_prob ' \
f'should be in range [0,1], got {random_negative_prob} instead.'
self.magnitude = magnitude
self.pad_val = pad_val
self.prob = prob
self.direction = direction
self.random_negative_prob = random_negative_prob
self.interpolation = interpolation
def __call__(self, results):
if np.random.rand() > self.prob:
return results
magnitude = random_negative(self.magnitude, self.random_negative_prob)
for key in results.get('img_fields', ['img']):
img = results[key]
img_sheared = mmcv.imshear(
img,
magnitude,
direction=self.direction,
border_value=self.pad_val,
interpolation=self.interpolation)
results[key] = img_sheared.astype(img.dtype)
return results
def __repr__(self):
repr_str = self.__class__.__name__
repr_str += f'(magnitude={self.magnitude}, '
repr_str += f'pad_val={self.pad_val}, '
repr_str += f'prob={self.prob}, '
repr_str += f'direction={self.direction}, '
repr_str += f'random_negative_prob={self.random_negative_prob}, '
repr_str += f'interpolation={self.interpolation})'
return repr_str