Should the input data be normalized using keras pre-trained models
According to Very Deep Convolutional Networks for Large-Scale Image Recognition, which is the paper that first presented VGG: &quot;...The only pre-processing we do is subtracting the mean RGB value, computed on the training set, from each pixel.&quot;- (Karen Simonyan, Andrew Zisserman).
I am certain that Keras provides a preprocess function based on the above mentioned principle.
Checkout: tensorflow.keras.applications.vgg16.preprocess_input
If it is in the TF version, its certainly in the other version.