PixelData¶

class mmengine.structures.PixelData(*, metainfo=None, **kwargs)[source]¶

Data structure for pixel-level annotations or predictions.

All data items in data_fields of PixelData meet the following requirements:

They all have 3 dimensions in orders of channel, height, and width.
They should have the same height and width.

Examples

>>> metainfo = dict(
...     img_id=random.randint(0, 100),
...     img_shape=(random.randint(400, 600), random.randint(400, 600)))
>>> image = np.random.randint(0, 255, (4, 20, 40))
>>> featmap = torch.randint(0, 255, (10, 20, 40))
>>> pixel_data = PixelData(metainfo=metainfo,
...                        image=image,
...                        featmap=featmap)
>>> print(pixel_data.shape)
(20, 40)

>>> # slice
>>> slice_data = pixel_data[10:20, 20:40]
>>> assert slice_data.shape == (10, 20)
>>> slice_data = pixel_data[10, 20]
>>> assert slice_data.shape == (1, 1)

>>> # set
>>> pixel_data.map3 = torch.randint(0, 255, (20, 40))
>>> assert tuple(pixel_data.map3.shape) == (1, 20, 40)
>>> with self.assertRaises(AssertionError):
...     # The dimension must be 3 or 2
...     pixel_data.map2 = torch.randint(0, 255, (1, 3, 20, 40))

Parameters:: metainfo (dict | None) –

property shape¶: The shape of pixel data.