在中优化自定义conv2d层克拉斯特遣部队

2024-04-26 18:04:44 发布

您现在位置:Python中文网/ 问答频道 /正文

我正在尝试有效地实现以下类型的conv2d层。我认为当前的实现是可行的,但效率非常低。你知道吗

输入大小张量

(批量×宽×高×厚)

输出张量

(批量×宽×高×粗)

该层采用两个参数,单位数(C_)和K conv内核列表(提前知道)。每个conv内核的大小是(W,H,1,N),其中N是输出通道数(in通道为1)。注意,同一个like中的不同内核有不同的Ns!你知道吗

首先,我们应用一个紧密连接的层(可训练的)变换输入形状

(批量大小x宽x高x厚)

然后,我想将每个卷积核应用到每个通道。你知道吗

这将导致C\u x K x(批量大小x W x H x N)

然后,我想沿着N取一个最大值(因此得到(batch_size x W x H x 1))并连接所有要得到的值

(批量×宽×高×厚×厚)

(所以Cïout=Cïu x K)

这里有一种方法可以实现这一点,但是训练时间非常慢,而且这在GPU上不起作用:

import tensorflow as tf
from tensorflow.keras import layers

class fixedConvLayer(layers.Dense):

    def __init__(self, units, conv_kernels, **params):
        params['units']=units
        self.conv_kernels_numpy = conv_kernels
        super().__init__(**params)
        return

    def build(self, input_shape):

        super().build(input_shape)
        self.conv_kernels = [tf.convert_to_tensor(np.reshape(kernels,[3,3,1,-1]))                                                           
                                  for kernels in self.conv_kernels_numpy]

        return 

    def comp_filters(self,channel):

        return tf.concat([
                    tf.math.reduce_max(tf.nn.conv2d(channel,
                                      filter=kernel,
                                      strides=1,
                                      padding='SAME'),axis=3,keepdims=True)

                        for kernel in self.conv_kernels],axis=3)


    def call(self,inputs):

        #take from Dense definition and slightly modify
        inputs = tf.convert_to_tensor(inputs)
        rank = tf.rank(inputs)
        if rank != 4:
            assert 'Rank expected to be 4'


        # Broadcasting is required for the inputs.
        outputs = tf.tensordot(inputs, self.kernel, [[3], [0]])

        # Reshape the output back to the original ndim of the input.
        shape = inputs.shape.as_list()
        output_shape = shape[:-1] + [self.units]
        outputs.set_shape(output_shape)

        if self.use_bias:
            outputs = tf.nn.bias_add(outputs, self.bias)
        if self.activation is not None:
            outputs = self.activation(outputs)  

        #apply the conv filters
        channel_list = tf.split(outputs,num_or_size_splits= self.units,axis = -1)
        max_layers = tf.concat([self.comp_filters(channel) for channel in channel_list],axis=3)

        return max_layers

Tags: theinselfreturnlayerstfdefchannel