---
title: "BNNSDirectApplyQuantizer(_:_:_:_:_:)"
framework: accelerate
role: symbol
role_heading: Function
path: "accelerate/bnnsdirectapplyquantizer(_:_:_:_:_:)"
---

# BNNSDirectApplyQuantizer(_:_:_:_:_:)

Applies a quantization layer directly to two input matrices.

## Declaration

```swift
func BNNSDirectApplyQuantizer(_ layer_params: UnsafePointer<BNNSLayerParametersQuantization>, _ filter_params: UnsafePointer<BNNSFilterParameters>?, _ batch_size: Int, _ input_stride: Int, _ output_stride: Int) -> Int32
```

## Parameters

- `layer_params`: The layer parameters.
- `filter_params`: The filter runtime parameters.
- `batch_size`: The number of input-output pairs.
- `input_stride`: The increment, in values, between inputs.
- `output_stride`: The increment, in values, between outputs.

## Discussion

Discussion Use this function, in conjunction with a BNNSLayerParametersQuantization, to convert tensors to different precisions. Pass the BNNSQuantizerFunctionQuantize quantizer function to convert a higher-precsion tensor to a lower-precision tensor. Pass BNNSQuantizerFunctionDequantize to convert a lower-precsion tensor to a higher-precision tensor. Quantization supports the following conversions:  |   |  Dequantization supports the following conversions:  |   |  You can provide optional scale and bias that the function applies during conversion. Quantization returns y = scale*x + bias, and dequantization returns y = (x-bias)/scale. If you supply scale and bias descriptors, they must have a vector layout and a size that matches the size of the axis that you specify. If you’re applying scale and bias to the entire tensor, scale and bias descriptors must have a size of 1. See BNNSQuantizerFunctionDequantize and BNNSQuantizerFunctionQuantize for examples of using this function.

## See Also

### Quantization functions

- [quantize(batchSize:input:output:axis:scale:bias:filterParameters:)](accelerate/bnns/quantize(batchsize:input:output:axis:scale:bias:filterparameters:).md)
- [dequantize(batchSize:input:output:axis:scale:bias:filterParameters:)](accelerate/bnns/dequantize(batchsize:input:output:axis:scale:bias:filterparameters:).md)
- [BNNSQuantizerFunction](accelerate/bnnsquantizerfunction.md)
- [BNNSLayerParametersQuantization](accelerate/bnnslayerparametersquantization.md)