使用 ImageDataGenerator 将图像重塑为 [-1, 1]

Question

是否可以使用 ImageDataGenerator 将 [0, 255] 中的图像重塑为 [-1, 1]？

我已经看到我可以使用重塑参数将图像与一个值相乘，但这只让我有可能将它重塑为 [0, 1]

Answer 1

您可以在 Keras ImageDataGenerator class 中使用 preprocessing_function。

preprocessing_function: function that will be applied 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.

#preprocessing_function function
def changeRange(image):

   image[:, :, 0] = [(i/128.0)-1 for i in image[:, :, 0]]
   image[:, :, 1] = [(i/128.0)-1 for i in image[:, :, 1]]
   image[:, :, 2] = [(i/128.0)-1 for i in image[:, :, 2]]

   return image

#data augementation
train_datagen = ImageDataGenerator(
   rescale = None,
   preprocessing_function=changeRange)

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