python - CNN 喀拉斯 : ValueError: Negative dimension size caused by subtracting 3 from 2 for 'conv2d

Question

我在使用 Keras 时遇到此错误:是因为input_size不大于过滤器吗？

如果input_shape=(64,64,3)))，则不会出现错误。

 ``ValueError: Negative dimension size caused by subtracting 3 from 2 for 
  'conv2d_24/convolution' (op: 'Conv2D') with input shapes: [?,2,2,128], 
  [3,3,128,128].

我的代码在这里:

from keras import layers
from keras import models
model = models.Sequential()
model.add(layers.Conv2D(32, (3, 3), activation='relu',                     
                                    input_shape=(32, 32, 3))) 
model.add(layers.MaxPooling2D((2, 2)))
model.add(layers.Conv2D(64, (3, 3), activation='relu'))
model.add(layers.MaxPooling2D((2, 2)))
model.add(layers.Conv2D(128, (3, 3), activation='relu'))
model.add(layers.MaxPooling2D((2, 2)))
model.add(layers.Conv2D(128, (3, 3), activation='relu'))
model.add(layers.MaxPooling2D((2, 2)))
model.add(layers.Flatten())
model.add(layers.Dense(512, activation='relu'))
model.add(layers.Dense(1, activation='sigmoid'))

Answer 1

默认图层填充是有效，这意味着没有填充。这样维度就从 32 减少到 16，而不是 15。您可以使用 padding='same' 代替。在这种情况下，输出的长度与原始输入的长度相同。

from keras import layers
from keras import models
model = models.Sequential()
model.add(layers.Conv2D(32, (3, 3), activation='relu',padding='same',                     
                                    input_shape=(32, 32, 3))) 
model.add(layers.MaxPooling2D((2, 2)))
model.add(layers.Conv2D(64, (3, 3), activation='relu',padding='same'))
model.add(layers.MaxPooling2D((2, 2),padding='same'))
model.add(layers.Conv2D(128, (3, 3), activation='relu',padding='same'))
model.add(layers.MaxPooling2D((2, 2),padding='same'))
model.add(layers.Conv2D(128, (3, 3), activation='relu',padding='same'))
model.add(layers.MaxPooling2D((2, 2),padding='same'))
model.add(layers.Flatten())
model.add(layers.Dense(512, activation='relu'))
model.add(layers.Dense(1, activation='sigmoid'))