---
title: "BNNSCropResizeBackward(_:_:_:_:_:)"
framework: accelerate
role: symbol
role_heading: Function
path: "accelerate/bnnscropresizebackward(_:_:_:_:_:)"
---

# BNNSCropResizeBackward(_:_:_:_:_:)

Applies a crop-resize filter backward to generate gradients.

## Declaration

```swift
func BNNSCropResizeBackward(_ layer_params: UnsafePointer<BNNSLayerParametersCropResize>, _ in_delta: UnsafeMutablePointer<BNNSNDArrayDescriptor>, _ roi: UnsafePointer<BNNSNDArrayDescriptor>, _ out_delta: UnsafePointer<BNNSNDArrayDescriptor>, _ filter_params: UnsafePointer<BNNSFilterParameters>?) -> Int32
```

## Parameters

- `layer_params`: A pointer to the layer parameters.
- `in_delta`: A pointer to the input delta descriptor.
- `roi`: A pointer to the regions of interest array descriptor.
- `out_delta`: A pointer to the output delta descriptor.
- `filter_params`: Runtime filter parameters.

## See Also

### Crop-resize layers

- [BNNS.CropResizeLayer](accelerate/bnns/cropresizelayer.md)
- [BNNSCropResize(_:_:_:_:_:)](accelerate/bnnscropresize(_:_:_:_:_:).md)
- [BNNSLayerParametersCropResize](accelerate/bnnslayerparameterscropresize.md)
- [BNNSBoxCoordinateMode](accelerate/bnnsboxcoordinatemode.md)
- [BNNSLinearSamplingMode](accelerate/bnnslinearsamplingmode.md)