def _shear_img(self,
results,
magnitude,
direction='horizontal',
interpolation='bilinear'):
"""Shear the image.
Args:
results (dict): Result dict from loading pipeline.
magnitude (int | float): The magnitude used for shear.
direction (str): The direction for shear, either "horizontal"
or "vertical".
interpolation (str): Same as in :func:`mmcv.imshear`.
"""
for key in results.get('img_fields', ['img']):
img = results[key]
img_sheared = mmcv.imshear(img,
magnitude,
direction,
border_value=self.img_fill_val,
interpolation=interpolation)
results[key] = img_sheared.astype(img.dtype)
def test_imshear(self):
img = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]]).astype(np.uint8)
assert_array_equal(mmcv.imshear(img, 0), img)
# magnitude=1, horizontal
img_sheared = np.array([[1, 2, 3], [0, 4, 5], [0, 0, 7]],
dtype=np.uint8)
assert_array_equal(mmcv.imshear(img, 1), img_sheared)
# magnitude=-1, vertical
img_sheared = np.array([[1, 5, 9], [4, 8, 0], [7, 0, 0]],
dtype=np.uint8)
assert_array_equal(mmcv.imshear(img, -1, 'vertical'), img_sheared)
# magnitude=1, vertical, borderValue=100
borderValue = 100
img_sheared = np.array(
[[1, borderValue, borderValue], [4, 2, borderValue], [7, 5, 3]],
dtype=np.uint8)
assert_array_equal(mmcv.imshear(img, 1, 'vertical', borderValue),
img_sheared)
# magnitude=1, vertical, borderValue=100, img shape (h,w,3)
img = np.stack([img, img, img], axis=-1)
img_sheared = np.stack([img_sheared, img_sheared, img_sheared],
axis=-1)
assert_array_equal(mmcv.imshear(img, 1, 'vertical', borderValue),
img_sheared)
# test tuple format of borderValue
assert_array_equal(
mmcv.imshear(img, 1, 'vertical',
(borderValue, borderValue, borderValue)), img_sheared)
# test invalid length of borderValue
with pytest.raises(AssertionError):
mmcv.imshear(img, 0.5, 'horizontal', (borderValue, ))
# test invalid type of borderValue
with pytest.raises(ValueError):
mmcv.imshear(img, 0.5, 'horizontal', [borderValue])
# test invalid value of direction
with pytest.raises(AssertionError):
mmcv.imshear(img, 0.5, 'diagonal')
