我将使用Keras的 ImageDataGenerator 类（在 keras / preprocessing / image.py 中）来训练神经网络。我将为训练数据提供一个生成器，为测试数据提供另一个生成器。但是，某些参数似乎适用于图像的预处理，而其他参数则试图扩充数据集。
我希望训练和测试数据都以相同的方式进行预处理，但是我不希望我的测试集被各种图像变换“增强”。因此，如果我相信这一点是正确的，那么以下参数用于预处理，并且可以由两个数据集共享：
featurewise_center: Boolean.
Set input mean to 0 over the dataset, feature-wise.
samplewise_center: Boolean. Set each sample mean to 0.
featurewise_std_normalization: Boolean.
Divide inputs by std of the dataset, feature-wise.
samplewise_std_normalization: Boolean. Divide each input by its std.
zca_epsilon: epsilon for ZCA whitening. Default is 1e-6.
zca_whitening: Boolean. Apply ZCA whitening.
fill_mode: One of {"constant", "nearest", "reflect" or "wrap"}.
Default is 'nearest'.
Points outside the boundaries of the input are filled
according to the given mode:
- 'constant': kkkkkkkk|abcd|kkkkkkkk (cval=k)
- 'nearest': aaaaaaaa|abcd|dddddddd
- 'reflect': abcddcba|abcd|dcbaabcd
- 'wrap': abcdabcd|abcd|abcdabcd
cval: Float or Int.
Value used for points outside the boundaries
when `fill_mode = "constant"`.
rescale: rescaling factor. Defaults to None.
If None or 0, no rescaling is applied,
otherwise we multiply the data by the value provided
(after applying all other transformations).
preprocessing_function: function that will be implied on each input.
The function will run after the image is resized and augmented.
The function should take one argument:
one image (Numpy tensor with rank 3),
and should output a Numpy tensor with the same shape.
data_format: Image data format,
either "channels_first" or "channels_last".
"channels_last" mode means that the images should have shape
`(samples, height, width, channels)`,
"channels_first" mode means that the images should have shape
`(samples, 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".
dtype: Dtype to use for the generated arrays.
这些参数是用于数据扩充的，应仅应用于训练集：
rotation_range: Int. Degree range for random rotations.
width_shift_range: Float, 1-D array-like or int
- float: fraction of total width, if < 1, or pixels if >= 1.
- 1-D array-like: random elements from the array.
- int: integer number of pixels from interval
`(-width_shift_range, +width_shift_range)`
- With `width_shift_range=2` possible values
are integers `[-1, 0, +1]`,
same as with `width_shift_range=[-1, 0, +1]`,
while with `width_shift_range=1.0` possible values are floats
in the interval [-1.0, +1.0).
height_shift_range: Float, 1-D array-like or int
- float: fraction of total height, if < 1, or pixels if >= 1.
- 1-D array-like: random elements from the array.
- int: integer number of pixels from interval
`(-height_shift_range, +height_shift_range)`
- With `height_shift_range=2` possible values
are integers `[-1, 0, +1]`,
same as with `height_shift_range=[-1, 0, +1]`,
while with `height_shift_range=1.0` possible values are floats
in the interval [-1.0, +1.0).
brightness_range: Tuple or list of two floats. Range for picking
a brightness shift value from.
shear_range: Float. Shear Intensity
(Shear angle in counter-clockwise direction in degrees)
zoom_range: Float or [lower, upper]. Range for random zoom.
If a float, `[lower, upper] = [1-zoom_range, 1+zoom_range]`.
channel_shift_range: Float. Range for random channel shifts.
horizontal_flip: Boolean. Randomly flip inputs horizontally.
vertical_flip: Boolean. Randomly flip inputs vertically.
此外，我不确定验证集中的数据（由ImageDataGenerator类定义）是否（或应该）受提供增强的转换的约束。