> For the complete documentation index, see [llms.txt](https://deeplearning4j.konduit.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://deeplearning4j.konduit.ai/en-1.0.0-rewrite/model-import/overview-1/layers-core.md). # Core Layers ### Keras Core Layer Import Core layers are implemented in the [layers/core](https://github.com/eclipse/deeplearning4j/tree/master/deeplearning4j/deeplearning4j-modelimport/src/main/java/org/deeplearning4j/nn/modelimport/keras/layers/core) package of `deeplearning4j-modelimport`. #### Support Summary | Keras Layer | DL4J Equivalent | Supported | | ---------------------- | ----------------------------------------------------------- | --------- | | Dense | DenseLayer | Yes | | Activation | ActivationLayer | Yes | | Dropout | DropoutLayer | Yes | | Flatten | CnnToFeedForwardPreProcessor / RnnToFeedForwardPreProcessor | Yes | | Reshape | ReshapePreProcessor | Yes | | Merge | MergeVertex | Yes | | Permute | PermutePreProcessor | Yes | | RepeatVector | RepeatVector | Yes | | Lambda | SameDiffLambda | Yes | | ActivityRegularization | — | No | | Masking | MaskZeroLayer | Yes | | SpatialDropout1D | DropoutLayer (spatial 1D) | Yes | | SpatialDropout2D | DropoutLayer (spatial 2D) | Yes | | SpatialDropout3D | DropoutLayer (spatial 3D) | Yes | *** ### KerasPermute [source](https://github.com/eclipse/deeplearning4j/tree/master/deeplearning4j/deeplearning4j-modelimport/src/main/java/org/deeplearning4j/nn/modelimport/keras/layers/core/KerasPermute.java) Imports a Permute layer from Keras as a DL4J input preprocessor. **Constructor** ```java public KerasPermute(Map layerConfig) throws InvalidKerasConfigurationException, UnsupportedKerasConfigurationException ``` **Parameters:** * `layerConfig` — dictionary containing Keras layer configuration **isInputPreProcessor** ```java public boolean isInputPreProcessor() ``` Returns `true`; Permute is implemented as an input preprocessor in DL4J. **getInputPreprocessor** ```java public InputPreProcessor getInputPreprocessor(InputType... inputType) throws InvalidKerasConfigurationException ``` Returns the DL4J `InputPreProcessor` corresponding to the Permute configuration. **getOutputType** ```java public InputType getOutputType(InputType... inputType) throws InvalidKerasConfigurationException ``` Returns the output `InputType` after permutation. *** ### KerasFlatten [source](https://github.com/eclipse/deeplearning4j/tree/master/deeplearning4j/deeplearning4j-modelimport/src/main/java/org/deeplearning4j/nn/modelimport/keras/layers/core/KerasFlatten.java) Imports a Keras Flatten layer as a DL4J `CnnToFeedForwardInputPreProcessor` or `RnnToFeedForwardPreProcessor`, depending on the preceding layer type. **Constructor** ```java public KerasFlatten(Map layerConfig) throws InvalidKerasConfigurationException, UnsupportedKerasConfigurationException ``` **isInputPreProcessor** ```java public boolean isInputPreProcessor() ``` Returns `true`; Flatten is implemented as an input preprocessor. **getInputPreprocessor** ```java public InputPreProcessor getInputPreprocessor(InputType... inputType) throws InvalidKerasConfigurationException ``` Selects the correct DL4J preprocessor based on `inputType`. **getOutputType** ```java public InputType getOutputType(InputType... inputType) throws InvalidKerasConfigurationException ``` *** ### KerasReshape [source](https://github.com/eclipse/deeplearning4j/tree/master/deeplearning4j/deeplearning4j-modelimport/src/main/java/org/deeplearning4j/nn/modelimport/keras/layers/core/KerasReshape.java) Imports a Keras Reshape layer as a DL4J input preprocessor. **Constructor** ```java public KerasReshape(Map layerConfig) throws InvalidKerasConfigurationException, UnsupportedKerasConfigurationException ``` **isInputPreProcessor / getInputPreprocessor / getOutputType** Same pattern as KerasFlatten above. *** ### KerasMerge [source](https://github.com/eclipse/deeplearning4j/tree/master/deeplearning4j/deeplearning4j-modelimport/src/main/java/org/deeplearning4j/nn/modelimport/keras/layers/core/KerasMerge.java) Imports a Keras Merge layer as a DL4J graph vertex. Supports `add`, `multiply`, `subtract`, `average`, `maximum`, and `concatenate` modes. The `dot` mode is not supported. **Constructor** ```java public KerasMerge(Integer kerasVersion) throws UnsupportedKerasConfigurationException ``` **getOutputType** ```java public InputType getOutputType(InputType... inputType) ``` *** ### KerasDense [source](https://github.com/eclipse/deeplearning4j/tree/master/deeplearning4j/deeplearning4j-modelimport/src/main/java/org/deeplearning4j/nn/modelimport/keras/layers/core/KerasDense.java) Imports a Keras Dense layer as a DL4J `DenseLayer`. **Constructor** ```java public KerasDense(Map layerConfig) throws InvalidKerasConfigurationException, UnsupportedKerasConfigurationException ``` **getDenseLayer** ```java public DenseLayer getDenseLayer() ``` Returns the DL4J `DenseLayer`. **getOutputType** ```java public InputType getOutputType(InputType... inputType) throws InvalidKerasConfigurationException ``` **getNumParams** ```java public int getNumParams() ``` Returns the number of trainable parameters (weights + bias). **setWeights** ```java public void setWeights(Map weights) throws InvalidKerasConfigurationException ``` *** ### KerasDropout [source](https://github.com/eclipse/deeplearning4j/tree/master/deeplearning4j/deeplearning4j-modelimport/src/main/java/org/deeplearning4j/nn/modelimport/keras/layers/core/KerasDropout.java) Imports a Keras Dropout layer as a DL4J `DropoutLayer`. **Constructor** ```java public KerasDropout(Map layerConfig) throws InvalidKerasConfigurationException, UnsupportedKerasConfigurationException ``` **getDropoutLayer** ```java public DropoutLayer getDropoutLayer() ``` **getOutputType** ```java public InputType getOutputType(InputType... inputType) throws InvalidKerasConfigurationException ``` *** ### KerasMasking [source](https://github.com/eclipse/deeplearning4j/blob/master/deeplearning4j/deeplearning4j-modelimport/src/main/java/org/deeplearning4j/nn/modelimport/keras/layers/core/KerasMasking.java) Imports a Keras Masking layer as a DL4J `MaskZeroLayer`. *** ### KerasSpatialDropout [source](https://github.com/eclipse/deeplearning4j/blob/master/deeplearning4j/deeplearning4j-modelimport/src/main/java/org/deeplearning4j/nn/modelimport/keras/layers/core/KerasSpatialDropout.java) Imports Keras SpatialDropout1D, SpatialDropout2D, and SpatialDropout3D layers as DL4J spatial dropout variants. *** ### KerasLambda [source](https://github.com/eclipse/deeplearning4j/blob/master/deeplearning4j/deeplearning4j-modelimport/src/main/java/org/deeplearning4j/nn/modelimport/keras/layers/core/KerasLambda.java) Imports a Keras Lambda layer. The Lambda layer is mapped to a SameDiff-based lambda function in DL4J. The function body is serialized separately. *** ### KerasRepeatVector [source](https://github.com/eclipse/deeplearning4j/blob/master/deeplearning4j/deeplearning4j-modelimport/src/main/java/org/deeplearning4j/nn/modelimport/keras/layers/core/KerasRepeatVector.java) Imports a Keras RepeatVector layer, which repeats the input a fixed number of times along a new axis. *** ### Notes * `ActivityRegularization` has no direct DL4J equivalent and will throw `UnsupportedKerasConfigurationException` at import time. Apply regularization directly in the layer configuration instead. * The Permute, Flatten, and Reshape layers are all implemented as `InputPreProcessor` instances in DL4J rather than as trainable layers. --- # Agent Instructions This documentation is published with GitBook. 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