mindspore.ops.Conv3D

class mindspore.ops.Conv3D(out_channel, kernel_size, mode=1, pad_mode='valid', pad=0, stride=1, dilation=1, group=1, data_format='NCDHW')[source]

3D convolution layer.

Applies a 3D convolution over an input tensor which is typically of shape \((N, C_{in}, D_{in}, H_{in}, W_{in})\) and output shape \((N, C_{out}, D_{out}, H_{out}, W_{out})\), where \(N\) is batch size, \(C\) is channel number, \(D\) is depth, \(H, W\) is feature height and width respectively. the output value of a layer is calculated as:

\[\operatorname{out}\left(N_{i}, C_{\text {out}_j}\right)=\operatorname{bias}\left(C_{\text {out}_j}\right)+ \sum_{k=0}^{C_{in}-1} ccor(\text {weight}\left(C_{\text {out}_j}, k\right), \operatorname{input}\left(N_{i}, k\right))\]

where \(k\) is kernel, \(ccor\) is the cross-correlation , \(C_{in}\) is the channel number of the input, \(out_{j}\) corresponds to the \(j\)-th channel of the output and \(j\) is in the range of \([0, C_{out} - 1]\). \(\text{weight}(C_{\text{out}_j}, k)\) is a convolution kernel slice with shape \((\text{kernel_size[0]}, \text{kernel_size[1]}, \text{kernel_size[2]})\), where \(\text{kernel_size[0]}\), \(\text{kernel_size[1]}\) and \(\text{kernel_size[2]}\) are the depth, height and width of the convolution kernel respectively. \(\text{bias}\) is the bias parameter and \(\text{X}\) is the input tensor. The shape of full convolution kernel is \((C_{out}, C_{in} / \text{groups}, \text{kernel_size[0]}, \text{kernel_size[1]}, \text{kernel_size[2]})\), where groups is the number of groups to split input in the channel dimension.

For more details, please refer to the paper Gradient Based Learning Applied to Document Recognition .

If the ‘pad_mode’ is set to be “valid”, the output depth, height and width will be \(\left \lfloor{1 + \frac{D_{in} + 2 \times \text{padding} - \text{ks_d} - (\text{ks_d} - 1) \times (\text{dilation} - 1) }{\text{stride}}} \right \rfloor\) and \(\left \lfloor{1 + \frac{H_{in} + 2 \times \text{padding} - \text{ks_h} - (\text{ks_h} - 1) \times (\text{dilation} - 1) }{\text{stride}}} \right \rfloor\) and \(\left \lfloor{1 + \frac{W_{in} + 2 \times \text{padding} - \text{ks_w} - (\text{ks_w} - 1) \times (\text{dilation} - 1) }{\text{stride}}} \right \rfloor\) respectively. Where \(dilation\) is Spacing between kernel elements, \(stride\) is The step length of each step, \(padding\) is zero-padding added to both sides of the input.

Parameters

  • out_channel (int) – The number of output channel \(C_{out}\).

  • kernel_size (Union[int, tuple[int]]) – Specifies the depth, height and width of the 3D convolution window. It can be a single int or a tuple of 3 integers. Single int means the value is for the depth, height and width of the kernel. A tuple of 3 ints corresponds to the depth, height and width of the kernel respectively.

  • mode (int) – Modes for different convolutions. It is currently not used. Default: 1.

  • stride (Union[int, tuple[int]], optional) – The distance of kernel moving, it can be an int number that represents the depth, height and width of movement or a tuple of three int numbers that represent depth, height and width movement respectively. Default: 1.

  • pad_mode (str, optional) –

    Specifies padding mode. The optional values are “same”, “valid” and “pad”. Default: “valid”.

    • same: Adopts the way of completion. The depth, height and width of the output will be equal to the input x divided by stride. The padding will be evenly calculated in head and tail, top and bottom, left and right directions possiblily. Otherwise, the last extra padding will be calculated from the tail, bottom and the right side. If this mode is set, pad must be 0.

    • valid: Adopts the way of discarding. The possible largest depth, height and width of output will be returned without padding. Extra pixels will be discarded. If this mode is set, pad must be 0.

    • pad: Implicit paddings on both sides of the input in depth, height and width. The number of pad will be padded to the input Tensor borders. pad must be greater than or equal to 0.

  • pad (Union(int, tuple[int])) – The pad value to be filled. Default: 0. If pad is an integer, the paddings of head, tail, top, bottom, left and right are the same, equal to pad. If pad is a tuple of six integers, the padding of head, tail, top, bottom, left and right equal to pad[0], pad[1], pad[2], pad[3], pad[4] and pad[5] correspondingly.

  • dilation (Union[int, tuple[int]], optional) – The data type is int or a tuple of 3 integers \((dilation_d, dilation_h, dilation_w)\). Currently, dilation on depth only supports the case of 1 on Ascend backend. Specifies the dilation rate to use for dilated convolution. If set \(k > 1\), there will be \(k - 1\) pixels skipped for each sampling location. The value ranges for the depth, height, and width dimensions are [1, D], [1, H], and [1, W], respectively. Default: 1.

  • group (int, optional) – The number of groups into which the filter is divided. in_channels and out_channels must be divisible by group. Default: 1.

  • data_format (str) – The optional value for data format. Currently only support “NCDHW”.

Inputs:

  • x (Tensor) - Tensor of shape \((N, C_{in}, D_{in}, H_{in}, W_{in})\). Currently input data type only support float16 and float32.

  • weight (Tensor) - Set size of kernel is \((k_d, K_h, K_w)\), then the shape is \((C_{out}, C_{in}/groups, k_d, K_h, K_w)\). Currently weight data type only support float16 and float32.

  • bias (Tensor) - Tensor of shape \(C_{in}\). Currently, only support none.

Outputs:

Tensor, the value that applied 3D convolution. The shape is \((N, C_{out}, D_{out}, H_{out}, W_{out})\).

Raises

  • TypeError – If out_channel or group is not an int.

  • TypeError – If kernel_size, stride, pad or dilation is neither an int nor a tuple.

  • ValueError – If out_channel, kernel_size, stride or dilation is less than 1.

  • ValueError – If pad is less than 0.

  • ValueError – If pad_mode is not one of ‘same’, ‘valid’ or ‘pad’.

  • ValueError – If pad is a tuple whose length is not equal to 6.

  • ValueError – If pad_mode is not equal to ‘pad’ and pad is not equal to (0, 0, 0, 0, 0, 0).

  • ValueError – If data_format is not ‘NCDHW’.

Supported Platforms:

Ascend GPU CPU

Examples

>>> x = Tensor(np.ones([16, 3, 10, 32, 32]), mindspore.float16)
>>> weight = Tensor(np.ones([32, 3, 4, 3, 3]), mindspore.float16)
>>> conv3d = ops.Conv3D(out_channel=32, kernel_size=(4, 3, 3))
>>> output = conv3d(x, weight)
>>> print(output.shape)
(16, 32, 7, 30, 30)