mindspore.nn.Conv3dTranspose

class mindspore.nn.Conv3dTranspose(in_channels, out_channels, kernel_size, stride=1, pad_mode='same', padding=0, dilation=1, group=1, output_padding=0, has_bias=False, weight_init=None, bias_init=None, data_format='NCDHW', dtype=mstype.float32)

Calculates a 3D transposed convolution, which can be regarded as Conv3d for the gradient of the input. It also called deconvolution (although it is not an actual deconvolution).

The input is typically of shape \((N, C_{in}, D_{in}, H_{in}, W_{in})\), where \(N\) is batch size, \(C_{in}\) is a number of channels, \(D_{in}, H_{in}, W_{in}\) are the depth, height and width of the feature layer respectively.

When Conv3d and Conv3dTranspose are initialized with the same parameters, and pad_mode is set to 'pad', \(dilation * (kernel\_size - 1) - padding\) amount of zero will be paded to the depth, height and width directions of the input, they are inverses of each other in regard to the input and output shapes in this case. However, when stride > 1, Conv2d maps multiple input shapes to the same output shape. Deconvolutional network can refer to Deconvolutional Networks.

Parameters

• in_channels (int) – The channel number of the input tensor of the Conv3dTranspose layer.

• out_channels (int) – The channel number of the output tensor of the Conv3dTranspose layer.

• kernel_size (Union[int, tuple[int]]) – Specifies the depth, height and width of the 3D convolution kernel. The data type is an integer or a tuple of three integers. An integer represents the depth, height and width of the convolution kernel. A tuple of three integers represents the depth, height and width of the convolution kernel respectively.

• stride (Union[int, tuple[int]]) – The movement stride of the 3D convolution kernel. The data type is an integer or a tuple of three integers. An integer represents the movement step size in depth, height and width directions. A tuple of three integers represents the movement step size in the depth, height and width directions respectively. Default: 1 .

• pad_mode (str, optional) –

  Specifies the padding mode with a padding value of 0. It can be set to: "same" , "valid" or "pad" . Default: "same" .

  • "same": Pad the input around its depth/height/width dimension so that the shape of input and output are the same when stride is set to 1. The amount of padding to is calculated by the operator internally. If the amount is even, it isuniformly distributed around the input, if it is odd, the excess amount goes to the front/right/bottom side. If this mode is set, padding must be 0.

  • "valid": No padding is applied to the input, and the output returns the maximum possible depth, height and width. Extra pixels that could not complete a full stride will be discarded. If this mode is set, padding must be 0.

  • "pad": Pad the input with a specified amount. In this mode, the amount of padding in the depth, height and width dimension is determined by the padding parameter. If this mode is set, padding must be greater than or equal to 0.

• padding (Union(int, tuple[int])) – The number of padding on the depth, height and width directions of the input. The data type is an integer or a tuple of six integers. If padding is an integer, then the head, tail, top, bottom, left, and right padding are all equal to padding. If padding is a tuple of six integers, then the head, tail, top, bottom, left, and right padding is equal to padding[0], padding[1], padding[2], padding[3], padding[4] and padding[5] respectively. The value should be greater than or equal to 0. Default: 0 .

• dilation (Union[int, tuple[int]]) – Specifies the dilation rate to use for dilated convolution. The data type can be a single int or a tuple of 3 integers. A single int means the dilation size is the same in the depth, height and width directions. A tuple of 3 ints represents the dilation size in the depth, height and width directions, respectively. Assuming \(dilation=(d0, d1, d2)\), the convolutional kernel samples the input with a spacing of \(d0-1\) elements in the depth direction, \(d1-1\) elements in the height direction, \(d2-1\) elements in the width direction respectively. The values in the depth, height and width dimensions are in the ranges [1, D], [1, H] and [1, W], respectively. Default: 1 .

• group (int) – Splits filter into groups, in_channels and out_channels must be divisible by group. Default: 1 .

• output_padding (Union(int, tuple[int])) – The number of padding on the depth, height and width directions of the output. The data type is an integer or a tuple of three integers. If output_padding is an integer, then the depth, height, and width dimension padding are all equal to output_padding. If output_padding is a tuple of three integers, then the depth, height, and width padding is equal to output_padding[0], output_padding[1] and output_padding[2] respectively. The value should be greater than or equal to 0. Default: 0 .

• has_bias (bool) – Whether the Conv3dTranspose layer has a bias parameter. Default: False .

• weight_init (Union[Tensor, str, Initializer, numbers.Number]) – Initialization method of weight parameter. It can be a Tensor, a string, an Initializer or a numbers.Number. When a string is specified, values from 'TruncatedNormal' , 'Normal' , 'Uniform' , 'HeUniform' and 'XavierUniform' distributions as well as constant 'One' and 'Zero' distributions are possible. Alias 'xavier_uniform' , 'he_uniform' , 'ones' and 'zeros' are acceptable. Uppercase and lowercase are both acceptable. Refer to the values of Initializer for more details. Default: None , weight will be initialized using HeUniform.

• bias_init (Union[Tensor, str, Initializer, numbers.Number]) – Initialization method of bias parameter. Available initialization methods are the same as 'weight_init'. Refer to the values of Initializer for more details. Default: None , bias will be initialized using Uniform.

• data_format (str) – The optional value for data format. Currently only support 'NCDHW' . Default: 'NCDHW' .

• dtype (mindspore.dtype) – Dtype of Parameters. Default: mstype.float32 .

Inputs:

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

Outputs:

Tensor, the shape is \((N, C_{out}, D_{out}, H_{out}, W_{out})\).

pad_mode is 'same' :

\[\begin{split}\begin{array}{ll} \\ D_{out} = \left \lfloor{\frac{D_{in}}{\text{stride[0]}} + 1} \right \rfloor \\ H_{out} = \left \lfloor{\frac{H_{in}}{\text{stride[1]}} + 1} \right \rfloor \\ W_{out} = \left \lfloor{\frac{W_{in}}{\text{stride[2]}} + 1} \right \rfloor \\ \end{array}\end{split}\]

pad_mode is 'valid' :

\[\begin{split}\begin{array}{ll} \\ D_{out} = \left \lfloor{\frac{D_{in} - \text{dilation[0]} \times (\text{kernel_size[0]} - 1) } {\text{stride[0]}} + 1} \right \rfloor \\ H_{out} = \left \lfloor{\frac{H_{in} - \text{dilation[1]} \times (\text{kernel_size[1]} - 1) } {\text{stride[1]}} + 1} \right \rfloor \\ W_{out} = \left \lfloor{\frac{W_{in} - \text{dilation[2]} \times (\text{kernel_size[2]} - 1) } {\text{stride[2]}} + 1} \right \rfloor \\ \end{array}\end{split}\]

pad_mode is 'pad' :

\[\begin{split}\begin{array}{ll} \\ D_{out} = \left \lfloor{\frac{D_{in} + padding[0] + padding[1] - (\text{dilation[0]} - 1) \times \text{kernel_size[0]} - 1 }{\text{stride[0]}} + 1} \right \rfloor \\ H_{out} = \left \lfloor{\frac{H_{in} + padding[2] + padding[3] - (\text{dilation[1]} - 1) \times \text{kernel_size[1]} - 1 }{\text{stride[1]}} + 1} \right \rfloor \\ W_{out} = \left \lfloor{\frac{W_{in} + padding[4] + padding[5] - (\text{dilation[2]} - 1) \times \text{kernel_size[2]} - 1 }{\text{stride[2]}} + 1} \right \rfloor \\ \end{array}\end{split}\]

Raises

• TypeError – If in_channels, out_channels or group is not an int.

• TypeError – If kernel_size, stride, padding , dilation or output_padding is neither an int nor a tuple of three.

• TypeError – If input data type is not float16 or float32.

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

• ValueError – If padding is less than 0.

• ValueError – If pad_mode is not one of 'same', 'valid', 'pad'.

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

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

• ValueError – If data_format is not 'NCDHW'.

Supported Platforms:

Ascend GPU CPU

Examples

>>> import mindspore
>>> from mindspore import Tensor, nn
>>> import numpy as np
>>> x = Tensor(np.ones([32, 16, 10, 32, 32]), mindspore.float32)
>>> conv3d_transpose = nn.Conv3dTranspose(in_channels=16, out_channels=3, kernel_size=(4, 6, 2),
...                                       pad_mode='pad')
>>> output = conv3d_transpose(x)
>>> print(output.shape)
(32, 3, 13, 37, 33)