Instantiates the VGG16 model.
Usage
application_vgg16(
include_top = TRUE,
weights = "imagenet",
input_tensor = NULL,
input_shape = NULL,
pooling = NULL,
classes = 1000L,
classifier_activation = "softmax",
name = "vgg16"
)
Arguments
- include_top
whether to include the 3 fully-connected layers at the top of the network.
- weights
one of
NULL
(random initialization),"imagenet"
(pre-training on ImageNet), or the path to the weights file to be loaded.- input_tensor
optional Keras tensor (i.e. output of
keras_input()
) to use as image input for the model.- input_shape
optional shape tuple, only to be specified if
include_top
isFALSE
(otherwise the input shape has to be(224, 224, 3)
(withchannels_last
data format) or(3, 224, 224)
(with"channels_first"
data format). It should have exactly 3 input channels, and width and height should be no smaller than 32. E.g.(200, 200, 3)
would be one valid value.- pooling
Optional pooling mode for feature extraction when
include_top
isFALSE
.NULL
means that the output of the model will be the 4D tensor output of the last convolutional block.avg
means that global average pooling will be applied to the output of the last convolutional block, and thus the output of the model will be a 2D tensor.max
means that global max pooling will be applied.
- classes
optional number of classes to classify images into, only to be specified if
include_top
isTRUE
, and if noweights
argument is specified.- classifier_activation
A
str
or callable. The activation function to use on the "top" layer. Ignored unlessinclude_top=TRUE
. Setclassifier_activation=NULL
to return the logits of the "top" layer. When loading pretrained weights,classifier_activation
can only beNULL
or"softmax"
.- name
The name of the model (string).
Reference
For image classification use cases, see this page for detailed examples.
For transfer learning use cases, make sure to read the guide to transfer learning & fine-tuning.
The default input size for this model is 224x224.
Note
Each Keras Application expects a specific kind of input preprocessing.
For VGG16, call application_preprocess_inputs()
on your
inputs before passing them to the model.
application_preprocess_inputs()
will convert the input images from RGB to BGR,
then will zero-center each color channel with respect to the ImageNet
dataset, without scaling.