Python 如何将向量重塑为TensorFlow';s过滤器?

Python 如何将向量重塑为TensorFlow';s过滤器?,python,numpy,tensorflow,Python,Numpy,Tensorflow,我想将另一个网络训练的一些权重转移到TensorFlow,权重存储在一个向量中,如下所示: 1 2 3 9 10 11 3 4 5 12 13 14 6 7 8 15 16 17 img = np.zeros([1,3,224,224]) img = img - 1 img = np.rollaxis(img, 1, 4) weight_array = googleNet.layers[1].weights weight_array = np.reshape(wei

我想将另一个网络训练的一些权重转移到TensorFlow,权重存储在一个向量中,如下所示:

1 2 3     9  10 11
3 4 5     12 13 14
6 7 8     15 16 17
img = np.zeros([1,3,224,224])
img = img - 1
img = np.rollaxis(img, 1, 4)

weight_array = googleNet.layers[1].weights
weight_array = np.reshape(weight_array,[64,3,7,7])

biases_array = googleNet.layers[1].biases

tf_weight = tf.Variable(weight_array)

tf_img = tf.Variable(img)
tf_img = tf.cast(tf_img,tf.float32)

tf_biases = tf.Variable(biases_array)

conv_feature = tf.nn.bias_add(tf.nn.conv2d(tf_img,tf_weight,strides=[1,2,2,1],padding='SAME'),tf_biases)
sess = tf.Session()
sess.run(tf.initialize_all_variables())
feautre = sess.run(conv_feature)
[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18]

通过使用numpy,我可以将其重塑为两个3乘3的过滤器,如下所示:

1 2 3     9  10 11
3 4 5     12 13 14
6 7 8     15 16 17
img = np.zeros([1,3,224,224])
img = img - 1
img = np.rollaxis(img, 1, 4)

weight_array = googleNet.layers[1].weights
weight_array = np.reshape(weight_array,[64,3,7,7])

biases_array = googleNet.layers[1].biases

tf_weight = tf.Variable(weight_array)

tf_img = tf.Variable(img)
tf_img = tf.cast(tf_img,tf.float32)

tf_biases = tf.Variable(biases_array)

conv_feature = tf.nn.bias_add(tf.nn.conv2d(tf_img,tf_weight,strides=[1,2,2,1],padding='SAME'),tf_biases)
sess = tf.Session()
sess.run(tf.initialize_all_variables())
feautre = sess.run(conv_feature)
因此,我的过滤器的形状是
(1,2,3,3)
。然而,在TensorFlow中,过滤器的形状是
(3,3,2,1)

在将tf_权重重塑为预期形状后,权重变得混乱,我无法获得预期的卷积结果

具体来说,当图像或过滤器的形状为[数字、通道、大小、大小]时,我编写了一个卷积函数,它给出了正确的答案,但速度太慢:

def convol(images,weights,biases,stride):
    """
    Args:
      images:input images or features, 4-D tensor
      weights:weights, 4-D tensor
      biases:biases, 1-D tensor
      stride:stride, a float number
    Returns:
      conv_feature: convolved feature map
    """
    image_num = images.shape[0] #the number of input images or feature maps
    channel = images.shape[1] #channels of an image,images's shape should be like [n,c,h,w]
    weight_num = weights.shape[0] #number of weights, weights' shape should be like [n,c,size,size]
    ksize = weights.shape[2]
    h = images.shape[2]
    w = images.shape[3]
    out_h = (h+np.floor(ksize/2)*2-ksize)/2+1
    out_w = out_h

    conv_features = np.zeros([image_num,weight_num,out_h,out_w])
    for i in range(image_num):
        image = images[i,...,...,...]
        for j in range(weight_num):
            sum_convol_feature = np.zeros([out_h,out_w])
            for c in range(channel):
                #extract a single channel image
                channel_image = image[c,...,...]
                #pad the image
                padded_image = im_pad(channel_image,ksize/2)
                #transform this image to a vector
                im_col = im2col(padded_image,ksize,stride)

                weight = weights[j,c,...,...]
                weight_col = np.reshape(weight,[-1])
                mul = np.dot(im_col,weight_col)
                convol_feature = np.reshape(mul,[out_h,out_w])
                sum_convol_feature = sum_convol_feature + convol_feature
            conv_features[i,j,...,...] = sum_convol_feature + biases[j]
    return conv_features
相反,通过使用tensorflow的conv2d,如下所示:

1 2 3     9  10 11
3 4 5     12 13 14
6 7 8     15 16 17
img = np.zeros([1,3,224,224])
img = img - 1
img = np.rollaxis(img, 1, 4)

weight_array = googleNet.layers[1].weights
weight_array = np.reshape(weight_array,[64,3,7,7])

biases_array = googleNet.layers[1].biases

tf_weight = tf.Variable(weight_array)

tf_img = tf.Variable(img)
tf_img = tf.cast(tf_img,tf.float32)

tf_biases = tf.Variable(biases_array)

conv_feature = tf.nn.bias_add(tf.nn.conv2d(tf_img,tf_weight,strides=[1,2,2,1],padding='SAME'),tf_biases)
sess = tf.Session()
sess.run(tf.initialize_all_variables())
feautre = sess.run(conv_feature)

我得到的特征图是错误的。

不要使用
np。重塑
。可能吧

改用:

请注意,大小为3的两个轴的顺序没有改变。如果我给它们添加标签,两个
rollaxis
操作会导致形状更改为(1,2,31,32)->(1,31,32,2)->(31,32,2,1)。您的最终阵列如下所示:

>>> b
array([[[[ 1],
         [10]],

        [[ 2],
         [11]],

        [[ 3],
         [12]]],


       [[[ 4],
         [13]],

        [[ 5],
         [14]],

        [[ 6],
         [15]]],


       [[[ 7],
         [16]],

        [[ 8],
         [17]],

        [[ 9],
         [18]]]])
样本张量操作 我不知道这是否有帮助。考虑整形、收集、动态分割和分割操作,并使之适应您的需要。 下面是这些操作的说明,这些操作可以根据您的情况进行调整。我从我的git回购中复制了这个。我相信,如果您在ipython中运行此示例,您可以找出您真正想要的内容,并获得更好的洞察力

重塑、聚集、动态分区和拆分 聚集操作(tf.Gather()) 生成一个数组并测试聚集操作。请注意,这种快速原型制作方法:

  • 我们在Numpy中生成了一个数组,并在其上测试了张量流的运算
用法:根据索引从参数收集切片

索引必须是任意维的整数张量(通常为0-D或1-D)。通过一个例子可以最好地说明这一点:

array = np.array([[1,2,3],[4,9,6],[2,3,4],[7,8,0]])

array.shape


(4, 3)

In [27]:

gather_output0  = tf.gather(array,1)
gather_output01  = tf.gather(array,2)
gather_output02  = tf.gather(array,3)

gather_output11  = tf.gather(array,[1,2])
gather_output12  = tf.gather(array,[1,3])
gather_output13  = tf.gather(array,[3,2])




gather_output  = tf.gather(array,[1,0,2])
gather_output1  = tf.gather(array,[1,1,2])
gather_output2  = tf.gather(array,[1,2,1])

In [28]:

with tf.Session() as sess:
    print (gather_output0.eval());print("\n")
    print (gather_output01.eval());print("\n")
    print (gather_output02.eval());print("\n")  
    print (gather_output11.eval());print("\n")
    print (gather_output12.eval());print("\n")
    print (gather_output13.eval());print("\n")

    print (gather_output.eval());print("\n")
    print (gather_output1.eval());print("\n")
    print (gather_output2.eval());print("\n")
    #print (gather_output2.eval());print("\n")

[4 9 6]


[2 3 4]


[7 8 0]


[[4 9 6]
 [2 3 4]]


[[4 9 6]
 [7 8 0]]


[[7 8 0]
 [2 3 4]]


[[4 9 6]
 [1 2 3]
 [2 3 4]]


[[4 9 6]
 [4 9 6]
 [2 3 4]]


[[4 9 6]
 [2 3 4]
 [4 9 6]]
* we define (5,30) aray in numpy
* we split the array along axis 1
* We  specify the number of splits as 1-Dimen Tensor along axis 1. So we have 3 splits.

Specify an array

    Create a (5 by 30) numpy array. The syntax using numpy is shown below
    In [2]:

    ArrayBeforeSplitting = np.arange(150).reshape(5,30) 
    print ("Array shape without split operation is : " ,ArrayBeforeSplitting.shape)

    ('Array shape without split operation is : ', (5, 30))

    specify number of splits
    In [3]:

    split_1D = tf.Variable([8,13,9])
    print("specify number of partions using 1-Dimen Variable:" , tf.shape(split_1D))

    ('specify number of partions using 1-Dimen Variable:', <tf.Tensor 'Shape:0' shape=(1,) dtype=int32>)

    Use tf.split

    Make 3 splits aong y axis so that we have (5,8) ,(5,13),(5,9) splits. The axis 1 add up to give 30-- we can see axis 1 has 30 elements so the partition along that axis should add up to 30 otherwise it gives error.
    In [6]:

    split1,split2,split3 = tf.split(ArrayBeforeSplitting,split_1D,1)
    # we have 3 splits along axis 1 specified spcifically
    # by the split_1D . That is split axis 1D (with 30 elements) into partions with 8 ,13, and 9 elements while the x axis
    #remains constant

    In [7]:

    #INitialise global variables. because split_ID is a variable and needs to be initialised before being
    #used in a computational graph
    init_op = tf.global_variables_initializer()

    In [16]:

    with tf.Session() as sess:
        sess.run(init_op) # run variable initialisation.
        result=split1.eval();print("\n")
        print(result)
        print("the shape of the first split operation is : ",result.shape)
        result2=split2.eval();print("\n")
        print(result2)
        print("the shape of the second split operation is : ",result2.shape)

        result3=split3.eval();print("\n")
        print(result3)
        print("the shape of the third split operation is : ",result3.shape)


    [[  0   1   2   3   4   5   6   7]
     [ 30  31  32  33  34  35  36  37]
     [ 60  61  62  63  64  65  66  67]
     [ 90  91  92  93  94  95  96  97]
     [120 121 122 123 124 125 126 127]]
    ('the shape of the first split operation is : ', (5, 8))


    [[  8   9  10  11  12  13  14  15  16  17  18  19  20]
     [ 38  39  40  41  42  43  44  45  46  47  48  49  50]
     [ 68  69  70  71  72  73  74  75  76  77  78  79  80]
     [ 98  99 100 101 102 103 104 105 106 107 108 109 110]
     [128 129 130 131 132 133 134 135 136 137 138 139 140]]
    ('the shape of the second split operation is : ', (5, 13))
看看这个简单的例子:

  • 初始化简单数组
  • 测试采集操作

    在[11]中:

    array_simple = np.array([1,2,3])
    
    In [15]:
    
    print "shape of simple array is: ", array_simple.shape
    
    shape of simple array is:  (3,)
    
    In [57]:
    
    gather1  = tf.gather(array1,[0])
    gather01 = tf.gather(array1,[1])
    gather02 = tf.gather(array1,[2])
    
    gather2 = tf.gather(array1,[1,2])
    gather3 = tf.gather(array1,[0,1])
    
    with tf.Session() as sess:
        print (gather1.eval());print("\n")
        print (gather01.eval());print("\n")
        print (gather02.eval());print("\n")
        print (gather2.eval());print("\n")
        print (gather3.eval());print("\n")
    
    [1]
    
    
    [2]
    
    
    [3]
    
    
    [2 3]
    
    
    [1 2]
    
    
    tf.reshape( )
    
    Note:
    
    *  Use the same array that was initiated
    *  Do reshape using tf.reshape( )
    
    In [64]:
    
    array.shape # Confirm array shape
    
    Out[64]:
    
    (4, 3)
    
    In [74]:
    
    print ("This is the array\n" ,array) # see the output and compare with the initial array,
    
    This is the array
     [[1 2 3]
     [4 9 6]
     [2 3 4]
     [7 8 0]]
    
    In [84]:
    
    reshape_ops= tf.reshape(array,[-1,4]) # Note the parameters in reshpe
    reshape_ops1= tf.reshape(array,[-1,3]) # Note the parameters in reshpe
    reshape_ops2= tf.reshape(array,[-1,6]) # Note the parameters in reshpe
    
    reshape_ops_back1= tf.reshape(array,[6,-1]) # Note the parameters in reshpe
    reshape_ops_back2= tf.reshape(array,[3,-1]) # Note the parameters in reshpe
    reshape_ops_back3= tf.reshape(array,[4,-1]) # Note the parameters in reshpe
    
    In [86]:
    
    with tf.Session() as sess:
        print(reshape_ops.eval());print("\n")
        print(reshape_ops1.eval());print("\n")
        print(reshape_ops2.eval());print("\n")
        print ("Output when we reverse the parameters:");print("\n")
        print(reshape_ops_back1.eval());print("\n")
        print(reshape_ops_back2.eval());print("\n")
        print(reshape_ops_back3.eval());print("\n")
    
    [[1 2 3 4]
     [9 6 2 3]
     [4 7 8 0]]
    
    
    [[1 2 3]
     [4 9 6]
     [2 3 4]
     [7 8 0]]
    
    
    [[1 2 3 4 9 6]
     [2 3 4 7 8 0]]
    
    
    Output when we reverse the parameters:
    
    
    [[1 2]
     [3 4]
     [9 6]
     [2 3]
     [4 7]
     [8 0]]
    
    
    [[1 2 3 4]
     [9 6 2 3]
     [4 7 8 0]]
    
    
    [[1 2 3]
     [4 9 6]
     [2 3 4]
     [7 8 0]]
    
    注意:输入大小和输出大小必须相同---否则会产生错误。检查这一点的简单方法是,通过执行简单的乘法,确保可以将输入划分为重塑参数

动态单元分区 tf.split() 确保使用最新的tensorflow版本。否则,在旧版本中,此实现将产生错误

文件中对此作了如下规定:

split(value,num或size,axis=0,num=None,name='split')

它将张量分解为子传感器。通过一个例子可以最好地说明这一点:

array = np.array([[1,2,3],[4,9,6],[2,3,4],[7,8,0]])

array.shape


(4, 3)

In [27]:

gather_output0  = tf.gather(array,1)
gather_output01  = tf.gather(array,2)
gather_output02  = tf.gather(array,3)

gather_output11  = tf.gather(array,[1,2])
gather_output12  = tf.gather(array,[1,3])
gather_output13  = tf.gather(array,[3,2])




gather_output  = tf.gather(array,[1,0,2])
gather_output1  = tf.gather(array,[1,1,2])
gather_output2  = tf.gather(array,[1,2,1])

In [28]:

with tf.Session() as sess:
    print (gather_output0.eval());print("\n")
    print (gather_output01.eval());print("\n")
    print (gather_output02.eval());print("\n")  
    print (gather_output11.eval());print("\n")
    print (gather_output12.eval());print("\n")
    print (gather_output13.eval());print("\n")

    print (gather_output.eval());print("\n")
    print (gather_output1.eval());print("\n")
    print (gather_output2.eval());print("\n")
    #print (gather_output2.eval());print("\n")

[4 9 6]


[2 3 4]


[7 8 0]


[[4 9 6]
 [2 3 4]]


[[4 9 6]
 [7 8 0]]


[[7 8 0]
 [2 3 4]]


[[4 9 6]
 [1 2 3]
 [2 3 4]]


[[4 9 6]
 [4 9 6]
 [2 3 4]]


[[4 9 6]
 [2 3 4]
 [4 9 6]]
* we define (5,30) aray in numpy
* we split the array along axis 1
* We  specify the number of splits as 1-Dimen Tensor along axis 1. So we have 3 splits.

Specify an array

    Create a (5 by 30) numpy array. The syntax using numpy is shown below
    In [2]:

    ArrayBeforeSplitting = np.arange(150).reshape(5,30) 
    print ("Array shape without split operation is : " ,ArrayBeforeSplitting.shape)

    ('Array shape without split operation is : ', (5, 30))

    specify number of splits
    In [3]:

    split_1D = tf.Variable([8,13,9])
    print("specify number of partions using 1-Dimen Variable:" , tf.shape(split_1D))

    ('specify number of partions using 1-Dimen Variable:', <tf.Tensor 'Shape:0' shape=(1,) dtype=int32>)

    Use tf.split

    Make 3 splits aong y axis so that we have (5,8) ,(5,13),(5,9) splits. The axis 1 add up to give 30-- we can see axis 1 has 30 elements so the partition along that axis should add up to 30 otherwise it gives error.
    In [6]:

    split1,split2,split3 = tf.split(ArrayBeforeSplitting,split_1D,1)
    # we have 3 splits along axis 1 specified spcifically
    # by the split_1D . That is split axis 1D (with 30 elements) into partions with 8 ,13, and 9 elements while the x axis
    #remains constant

    In [7]:

    #INitialise global variables. because split_ID is a variable and needs to be initialised before being
    #used in a computational graph
    init_op = tf.global_variables_initializer()

    In [16]:

    with tf.Session() as sess:
        sess.run(init_op) # run variable initialisation.
        result=split1.eval();print("\n")
        print(result)
        print("the shape of the first split operation is : ",result.shape)
        result2=split2.eval();print("\n")
        print(result2)
        print("the shape of the second split operation is : ",result2.shape)

        result3=split3.eval();print("\n")
        print(result3)
        print("the shape of the third split operation is : ",result3.shape)


    [[  0   1   2   3   4   5   6   7]
     [ 30  31  32  33  34  35  36  37]
     [ 60  61  62  63  64  65  66  67]
     [ 90  91  92  93  94  95  96  97]
     [120 121 122 123 124 125 126 127]]
    ('the shape of the first split operation is : ', (5, 8))


    [[  8   9  10  11  12  13  14  15  16  17  18  19  20]
     [ 38  39  40  41  42  43  44  45  46  47  48  49  50]
     [ 68  69  70  71  72  73  74  75  76  77  78  79  80]
     [ 98  99 100 101 102 103 104 105 106 107 108 109 110]
     [128 129 130 131 132 133 134 135 136 137 138 139 140]]
    ('the shape of the second split operation is : ', (5, 13))
*我们用numpy定义(5,30)aray
*我们沿着轴1拆分阵列
*我们将分裂的数量指定为沿轴1的一维张量。所以我们有三个分裂。
指定一个数组
创建一个(5×30)numpy数组。使用numpy的语法如下所示
在[2]中:
排列前重新排列=np.arange(150)。重塑(5,30)
打印(“无拆分操作的数组形状为:”,ArrayBeforSplitting.shape)
('Array shape without split operation is:',(5,30))
指定拆分的数目
在[3]中:
split_1D=tf.变量([8,13,9])
打印(“使用一维变量指定分区数:”,tf.shape(split_1D))
(“使用1-Dimen变量指定分区数:”,)
使用tf.split
在y轴上做3次劈开,这样我们有(5,8),(5,13),(5,9)次劈开。轴1加起来等于30——我们可以看到轴1有30个元素,所以沿着该轴的分区应该加起来等于30,否则会产生错误。
在[6]中:
split1,split2,split3=tf.split(数组在重新排列前,split_1D,1)
#我们有3个特殊指定的沿轴1的拆分
#通过拆分。即将轴1D(包含30个元素)拆分为包含8、13和9个元素的分区,而x轴
#保持不变
在[7]中:
#初始化全局变量。因为split_ID是一个变量,需要在初始化之前进行初始化
#用于计算图形
init_op=tf.global_variables_initializer()
在[16]中:
使用tf.Session()作为sess:
sess.run(init_op)#运行变量初始化。
结果=split1.eval();打印(“\n”)
打印(结果)
打印(“第一次拆分操作的形状为:”,result.shape)
result2=split2.eval();打印(“\n”)
打印(结果2)
打印(“第二次拆分操作的形状为:”,result2.shape)
result3=split3.eval();打印(“\n”)
打印(结果3)
打印(“第三次拆分操作的形状为:”,result3.shape)
[[  0   1   2   3   4   5   6   7]
[ 30  31  32  33  34  35  36  37]
[ 60  61  62  63  64  65  66  67]
[ 90  91  92  93  94  95  96  97]
[120 121 122 123 124 125 126 127]]
('第一次拆分操作的形状为:',(5,8))
[[  8   9  10  11  12  13  14  15  16  17  18  19  20]
[ 38  39  40  41  42  43  44  45  46  47  48  49  50]
[ 68  69  70  71  72  73  74  75  76  77  78  79  80]
[ 98  99 100 101 102 103 104 105 106 107 108 109 110]
[128 129 130 131 132 133 134 135 136 137 138 139 140]]
('第二次拆分操作的形状为:',(5,13))

希望这有帮助

谢谢你的回答!我试过这个代码。但是,重新调整后的阵列无法按预期工作。我认为tensorflow的维度顺序是如此紧密。在numpy中,我们将图像重塑为类似于[number,channel,height,width]的四维张量,但在tensorflow中类似于[number,height,width,channel]。因此,在重塑之后,权重或图像变成了一个质量,我无法获得预期的正确卷积特征。那么,根据您的评论,您可能只需要
b=np.rollaxis(a,1,4)
。那也不行吗?不幸的是,我不熟悉tensorflow。但这绝对是一种解决问题的方法