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import numpy as np |
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from core.leras import nn |
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tf = nn.tf |
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class Conv2D(nn.LayerBase): |
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""" |
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default kernel_initializer - CA |
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use_wscale bool enables equalized learning rate, if kernel_initializer is None, it will be forced to random_normal |
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""" |
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def __init__(self, in_ch, out_ch, kernel_size, strides=1, padding='SAME', dilations=1, use_bias=True, use_wscale=False, kernel_initializer=None, bias_initializer=None, trainable=True, dtype=None, **kwargs ): |
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if not isinstance(strides, int): |
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raise ValueError ("strides must be an int type") |
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if not isinstance(dilations, int): |
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raise ValueError ("dilations must be an int type") |
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kernel_size = int(kernel_size) |
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if dtype is None: |
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dtype = nn.floatx |
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if isinstance(padding, str): |
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if padding == "SAME": |
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padding = ( (kernel_size - 1) * dilations + 1 ) // 2 |
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elif padding == "VALID": |
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padding = None |
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else: |
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raise ValueError ("Wrong padding type. Should be VALID SAME or INT or 4x INTs") |
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else: |
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padding = int(padding) |
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self.in_ch = in_ch |
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self.out_ch = out_ch |
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self.kernel_size = kernel_size |
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self.strides = strides |
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self.padding = padding |
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self.dilations = dilations |
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self.use_bias = use_bias |
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self.use_wscale = use_wscale |
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self.kernel_initializer = kernel_initializer |
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self.bias_initializer = bias_initializer |
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self.trainable = trainable |
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self.dtype = dtype |
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super().__init__(**kwargs) |
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def build_weights(self): |
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kernel_initializer = self.kernel_initializer |
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if self.use_wscale: |
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gain = 1.0 if self.kernel_size == 1 else np.sqrt(2) |
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fan_in = self.kernel_size*self.kernel_size*self.in_ch |
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he_std = gain / np.sqrt(fan_in) |
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self.wscale = tf.constant(he_std, dtype=self.dtype ) |
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if kernel_initializer is None: |
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kernel_initializer = tf.initializers.random_normal(0, 1.0, dtype=self.dtype) |
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self.weight = tf.get_variable("weight", (self.kernel_size,self.kernel_size,self.in_ch,self.out_ch), dtype=self.dtype, initializer=kernel_initializer, trainable=self.trainable ) |
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if self.use_bias: |
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bias_initializer = self.bias_initializer |
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if bias_initializer is None: |
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bias_initializer = tf.initializers.zeros(dtype=self.dtype) |
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self.bias = tf.get_variable("bias", (self.out_ch,), dtype=self.dtype, initializer=bias_initializer, trainable=self.trainable ) |
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def get_weights(self): |
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weights = [self.weight] |
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if self.use_bias: |
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weights += [self.bias] |
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return weights |
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def forward(self, x): |
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weight = self.weight |
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if self.use_wscale: |
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weight = weight * self.wscale |
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padding = self.padding |
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if padding is not None: |
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if nn.data_format == "NHWC": |
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padding = [ [0,0], [padding,padding], [padding,padding], [0,0] ] |
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else: |
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padding = [ [0,0], [0,0], [padding,padding], [padding,padding] ] |
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x = tf.pad (x, padding, mode='CONSTANT') |
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strides = self.strides |
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if nn.data_format == "NHWC": |
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strides = [1,strides,strides,1] |
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else: |
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strides = [1,1,strides,strides] |
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dilations = self.dilations |
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if nn.data_format == "NHWC": |
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dilations = [1,dilations,dilations,1] |
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else: |
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dilations = [1,1,dilations,dilations] |
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x = tf.nn.conv2d(x, weight, strides, 'VALID', dilations=dilations, data_format=nn.data_format) |
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if self.use_bias: |
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if nn.data_format == "NHWC": |
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bias = tf.reshape (self.bias, (1,1,1,self.out_ch) ) |
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else: |
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bias = tf.reshape (self.bias, (1,self.out_ch,1,1) ) |
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x = tf.add(x, bias) |
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return x |
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def __str__(self): |
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r = f"{self.__class__.__name__} : in_ch:{self.in_ch} out_ch:{self.out_ch} " |
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return r |
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nn.Conv2D = Conv2D |