---
title: "vImageConvert_ARGB16UtoARGB8888_dithered(_:_:_:_:_:)"
framework: accelerate
role: symbol
role_heading: Function
path: "accelerate/vimageconvert_argb16utoargb8888_dithered(_:_:_:_:_:)"
---

# vImageConvert_ARGB16UtoARGB8888_dithered(_:_:_:_:_:)

Converts an unsigned 16-bit-per-channel, 4-channel interleaved buffer to an 8-bit-per-channel, 4-channel interleaved buffer using the specified dithering algorithm.

## Declaration

```swift
func vImageConvert_ARGB16UtoARGB8888_dithered(_ src: UnsafePointer<vImage_Buffer>, _ dest: UnsafePointer<vImage_Buffer>, _ dither: Int32, _ permuteMap: UnsafePointer<UInt8>!, _ 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.
- `dither`: The dithering algorithm.
- `permuteMap`: An array of four 8-bit integers with the values 0, 1, 2, and 3, in some order. Each value specifies the channel from the source image that the function copies to the destination channel at the corresponding index.
- `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.

## Return Value

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

## Discussion

Discussion This function supports the following dithering algorithms:

## See Also

### Related Documentation

- [Improving the quality of quantized images with dithering](accelerate/improving-the-quality-of-quantized-images-with-dithering.md)

### Converting from unsigned 16-bit-per-channel buffers

- [vImageConvert_RGB16UtoRGB888_dithered(_:_:_:_:)](accelerate/vimageconvert_rgb16utorgb888_dithered(_:_:_:_:).md)
- [vImageConvert_ARGB16UToARGB8888(_:_:_:_:_:_:)](accelerate/vimageconvert_argb16utoargb8888(_:_:_:_:_:_:).md)