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# BNNS.ConvolutionLayer

A layer object that wraps a convolution filter and manages its deinitialization.

```
class ConvolutionLayer
```

## Topics

### Creating a Convolution Layer

[`convenience init?(type: BNNS.ConvolutionType, input: BNNSNDArrayDescriptor, weights: BNNSNDArrayDescriptor, output: BNNSNDArrayDescriptor, bias: BNNSNDArrayDescriptor?, padding: BNNS.ConvolutionPadding, activation: BNNS.ActivationFunction, groupCount: Int, stride: (x: Int, y: Int), dilationStride: (x: Int, y: Int), filterParameters: BNNSFilterParameters?)`](/documentation/Accelerate/BNNS/ConvolutionLayer/init(type:input:weights:output:bias:padding:activation:groupCount:stride:dilationStride:filterParameters:))

Returns a new convolution layer.

### Specifying a Convolution Type

[`enum ConvolutionType`](/documentation/Accelerate/BNNS/ConvolutionType)

Constants that describe convolution types.

### Specifying Convolution Padding

[`enum ConvolutionPadding`](/documentation/Accelerate/BNNS/ConvolutionPadding)

Constants that describe convolution padding modes.

### Applying a Convolution Layer

[`func applyBackward(batchSize: Int, input: BNNSNDArrayDescriptor, output: BNNSNDArrayDescriptor, outputGradient: BNNSNDArrayDescriptor, generatingInputGradient: BNNSNDArrayDescriptor, generatingWeightsGradient: BNNSNDArrayDescriptor?, generatingBiasGradient: BNNSNDArrayDescriptor?) throws`](/documentation/Accelerate/BNNS/ConvolutionLayer/applyBackward(batchSize:input:output:outputGradient:generatingInputGradient:generatingWeightsGradient:generatingBiasGradient:))

Applies the layer backward to generate input gradients.

## Relationships

### Inherited By

[`FullyConnectedLayer`](/documentation/Accelerate/BNNS/FullyConnectedLayer)

### Inherits From

[`UnaryLayer`](/documentation/Accelerate/BNNS/UnaryLayer)

---

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