layer_conv_2d
2D convolution layer (e.g. spatial convolution over images).
Description
This layer creates a convolution kernel that is convolved with the layer input to produce a tensor of outputs. If use_bias
is TRUE, a bias vector is created and added to the outputs. Finally, if activation
is not NULL
, it is applied to the outputs as well. When using this layer as the first layer in a model, provide the keyword argument input_shape
(list of integers, does not include the sample axis), e.g. input_shape=c(128, 128, 3)
for 128x128 RGB pictures in data_format="channels_last"
.
Usage
layer_conv_2d(
object,
filters,
kernel_size, strides = c(1L, 1L),
padding = "valid",
data_format = NULL,
dilation_rate = c(1L, 1L),
groups = 1L,
activation = NULL,
use_bias = TRUE,
kernel_initializer = "glorot_uniform",
bias_initializer = "zeros",
kernel_regularizer = NULL,
bias_regularizer = NULL,
activity_regularizer = NULL,
kernel_constraint = NULL,
bias_constraint = NULL,
input_shape = NULL,
batch_input_shape = NULL,
batch_size = NULL,
dtype = NULL,
name = NULL,
trainable = NULL,
weights = NULL
)
Arguments
Arguments | Description |
---|---|
object | What to compose the new Layer instance with. Typically a Sequential model or a Tensor (e.g., as returned by layer_input() ). The return value depends on object . If object is: - missing or NULL , the Layer instance is returned. - a Sequential model, the model with an additional layer is returned. - a Tensor, the output tensor from layer_instance(object) is returned. |
filters | Integer, the dimensionality of the output space (i.e. the number of output filters in the convolution). |
kernel_size | An integer or list of 2 integers, specifying the width and height of the 2D convolution window. Can be a single integer to specify the same value for all spatial dimensions. |
strides | An integer or list of 2 integers, specifying the strides of the convolution along the width and height. Can be a single integer to specify the same value for all spatial dimensions. Specifying any stride value != 1 is incompatible with specifying any dilation_rate value != 1. |
padding | one of "valid" or "same" (case-insensitive). Note that "same" is slightly inconsistent across backends with strides != 1, as described here |
data_format | A string, one of channels_last (default) or channels_first . The ordering of the dimensions in the inputs. channels_last corresponds to inputs with shape (batch, height, width, channels) while channels_first corresponds to inputs with shape (batch, channels, height, width) . It defaults to the image_data_format value found in your Keras config file at ~/.keras/keras.json . If you never set it, then it will be “channels_last”. |
dilation_rate | an integer or list of 2 integers, specifying the dilation rate to use for dilated convolution. Can be a single integer to specify the same value for all spatial dimensions. Currently, specifying any dilation_rate value != 1 is incompatible with specifying any stride value != 1. |
groups | A positive integer specifying the number of groups in which the input is split along the channel axis. Each group is convolved separately with filters / groups filters. The output is the concatenation of all the groups results along the channel axis. Input channels and filters must both be divisible by groups . |
activation | Activation function to use. If you don’t specify anything, no activation is applied (ie. “linear” activation: a(x) = x ). |
use_bias | Boolean, whether the layer uses a bias vector. |
kernel_initializer | Initializer for the kernel weights matrix. |
bias_initializer | Initializer for the bias vector. |
kernel_regularizer | Regularizer function applied to the kernel weights matrix. |
bias_regularizer | Regularizer function applied to the bias vector. |
activity_regularizer | Regularizer function applied to the output of the layer (its “activation”).. |
kernel_constraint | Constraint function applied to the kernel matrix. |
bias_constraint | Constraint function applied to the bias vector. |
input_shape | Dimensionality of the input (integer) not including the samples axis. This argument is required when using this layer as the first layer in a model. |
batch_input_shape | Shapes, including the batch size. For instance, batch_input_shape=c(10, 32) indicates that the expected input will be batches of 10 32-dimensional vectors. batch_input_shape=list(NULL, 32) indicates batches of an arbitrary number of 32-dimensional vectors. |
batch_size | Fixed batch size for layer |
dtype | The data type expected by the input, as a string (float32 , float64 , int32 …) |
name | An optional name string for the layer. Should be unique in a model (do not reuse the same name twice). It will be autogenerated if it isn’t provided. |
trainable | Whether the layer weights will be updated during training. |
weights | Initial weights for layer. |
Section
Input shape
4D tensor with shape: (samples, channels, rows, cols)
if data_format=‘channels_first’ or 4D tensor with shape: (samples, rows, cols, channels)
if data_format=‘channels_last’.
Output shape
4D tensor with shape: (samples, filters, new_rows, new_cols)
if data_format=‘channels_first’ or 4D tensor with shape: (samples, new_rows, new_cols, filters)
if data_format=‘channels_last’. rows
and cols
values might have changed due to padding.
See Also
Other convolutional layers: layer_conv_1d_transpose()
, layer_conv_1d()
, layer_conv_2d_transpose()
, layer_conv_3d_transpose()
, layer_conv_3d()
, layer_conv_lstm_2d()
, layer_cropping_1d()
, layer_cropping_2d()
, layer_cropping_3d()
, layer_depthwise_conv_1d()
, layer_depthwise_conv_2d()
, layer_separable_conv_1d()
, layer_separable_conv_2d()
, layer_upsampling_1d()
, layer_upsampling_2d()
, layer_upsampling_3d()
, layer_zero_padding_1d()
, layer_zero_padding_2d()
, layer_zero_padding_3d()