extract_patches¶

dragon.vision.extract_patches(
  inputs,
  kernel_shape=(3, 3),
  strides=1,
  pads=0,
  dilations=1,
  padding='VALID',
  data_format='NCHW',
  **kwargs
)[source]¶

Extract the sliding patches from input.

• If data_format is 'NCHW', excepts input shape \((N, C, D1, D2, ...)\), and output shape is \((N, C \times \prod(\text{kernel\_shape}), D1_{\text{out}}, D2_{\text{out}}, ...)\).
• If data_format is 'NHWC', excepts input shape \((N, D1, D2, ..., C)\), and output shape is \((N, D1_{\text{out}}, D2_{\text{out}}, ..., \prod(\text{kernel\_shape}) \times C)\).
• If padding is 'VALID', pads controls the explicit padding size. Otherwise, size are computed automatically use the given method.

Examples:

for i in range(3):
    ndim = i + 1
    x = dragon.ones((1, 2) + (2,) * ndim)
    y = dragon.vision.extract_patches(x, kernel_shape=(2,) * ndim)
    assert y.shape == (1, 2 * (2 ** ndim)) + (1,) * ndim

Parameters:

• inputs (dragon.Tensor) – The input tensor.
• kernel_shape (Sequence[int], optional, default=(3, 3)) – The shape of sliding window.
• strides (Union[int, Sequence[int]], optional, default=1) – The stride of sliding window.
• pads (Union[int, Sequence[int]], optional, default=0) – The zero padding size.
• dilations (Union[int, Sequence[int]], optional, default=1) – The dilated rate of sliding window.
• padding (str, optional, default='VALID') – 'VALID', 'SAME', 'SAME_UPPER' or 'SAME_LOWER'.
• data_format (str, optional, default='NCHW') – 'NCHW' or 'NHWC'.

Returns:

dragon.Tensor – The output tensor.