---
title: "vImageContrastStretch_ARGB8888(_:_:_:)"
framework: accelerate
role: symbol
role_heading: Function
path: "accelerate/vimagecontraststretch_argb8888(_:_:_:)"
---

# vImageContrastStretch_ARGB8888(_:_:_:)

Performs contrast stretching on an 8-bit-per-channel, 4-channel interleaved buffer.

## Declaration

```swift
func vImageContrastStretch_ARGB8888(_ src: UnsafePointer<vImage_Buffer>, _ dest: UnsafePointer<vImage_Buffer>, _ flags: vImage_Flags) -> vImage_Error
```

## Parameters

- `src`: The source vImage buffer.
- `dest`: A pointer to the destination vImage buffer structure. You’re responsible for filling out the doc://com.apple.accelerate/documentation/Accelerate/vImage_Buffer/height, doc://com.apple.accelerate/documentation/Accelerate/vImage_Buffer/width, and doc://com.apple.accelerate/documentation/Accelerate/vImage_Buffer/rowBytes fields of this structure, and for allocating a data buffer of the appropriate size. On return, the data buffer this structure points to contains the destination image data. When you no longer need the data buffer, deallocate the memory to prevent memory leaks.
- `flags`: The options to use when performing the operation. If your code implements its own tiling or its own multithreading, pass doc://com.apple.accelerate/documentation/Accelerate/kvImageDoNotTile; otherwise, pass doc://com.apple.accelerate/documentation/Accelerate/kvImageNoFlags. To specify that the function doesn’t apply the operation to the alpha channel, set the doc://com.apple.accelerate/documentation/Accelerate/kvImageLeaveAlphaUnchanged flag.

## Return Value

Return Value kvImageNoError; otherwise, one of the error codes in Data Types and Constants.

## Discussion

Discussion Contrast stretching evenly distributes a histogram’s pixel values across the full range of available pixel values. This technique is ideal for enhancing the contrast of an image with pixel values concentrated in one area of the intensity spectrum.

## See Also

### Related Documentation

- [Enhancing image contrast with histogram manipulation](accelerate/enhancing-image-contrast-with-histogram-manipulation.md)
- [Specifying histograms with vImage](accelerate/specifying-histograms-with-vimage.md)

### Performing contrast stretching

- [vImageContrastStretch_Planar8(_:_:_:)](accelerate/vimagecontraststretch_planar8(_:_:_:).md)
- [vImageContrastStretch_PlanarF(_:_:_:_:_:_:_:)](accelerate/vimagecontraststretch_planarf(_:_:_:_:_:_:_:).md)
- [vImageContrastStretch_ARGBFFFF(_:_:_:_:_:_:_:)](accelerate/vimagecontraststretch_argbffff(_:_:_:_:_:_:_:).md)