---
title: "overwriteChannels(_:withScalar:destination:)"
framework: accelerate
role: symbol
role_heading: Instance Method
path: "accelerate/vimage/pixelbuffer/overwritechannels(_:withscalar:destination:)-ev8q"
---

# overwriteChannels(_:withScalar:destination:)

Overwrites the pixels of one or more channels of the pixel buffer with the provided 32-bit scalar value.

## Declaration

```swift
func overwriteChannels(_ channels: [UInt8], withScalar scalar: Pixel_F, destination: vImage.PixelBuffer<Format>)
```

## Parameters

- `channels`: An array that contains the indices of the channels that the function overwrites.
- `scalar`: The value that the function writes to the channels.
- `destination`: The destination pixel buffer.

## Discussion

Discussion Use this function to overwrite one or more channels of an interleaved buffer with a scalar value. The following code overwrites channels 1 and 3 with the value 99: let pixelValues: [Pixel_F] = [ 1, 2, 3, 4,                                5, 6, 7, 8 ] let buffer = vImage.PixelBuffer(pixelValues: pixelValues,                                 size: vImage.Size(width: 1,                                                   height: 2),                                 pixelFormat: vImage.InterleavedFx4.self)

let destination = vImage.PixelBuffer(size: vImage.Size(width: 1,                                                        height: 2),                                      pixelFormat: vImage.InterleavedFx4.self)

buffer.overwriteChannels([3, 1],                          withScalar: 99,                          destination: destination) On return, destination.array contains the following values: [ 1, 99, 3, 99,   5, 99, 7, 99 ]

## See Also

### Overwriting Channels

- [overwriteChannels(withScalar:)](accelerate/vimage/pixelbuffer/overwritechannels(withscalar:)-3zb93.md)
- [overwriteChannels(withScalar:)](accelerate/vimage/pixelbuffer/overwritechannels(withscalar:)-1hrrg.md)
- [overwriteChannels(withScalar:)](accelerate/vimage/pixelbuffer/overwritechannels(withscalar:)-1wm1o.md)
- [overwriteChannels(_:withScalar:destination:)](accelerate/vimage/pixelbuffer/overwritechannels(_:withscalar:destination:)-57ov2.md)
- [overwriteChannels(_:withPixel:destination:)](accelerate/vimage/pixelbuffer/overwritechannels(_:withpixel:destination:)-6fab6.md)
- [overwriteChannels(_:withPixel:destination:)](accelerate/vimage/pixelbuffer/overwritechannels(_:withpixel:destination:)-6zw3o.md)
- [overwriteChannels(_:withPixel:destination:)](accelerate/vimage/pixelbuffer/overwritechannels(_:withpixel:destination:)-6pbz8.md)
- [overwriteChannels(_:withPlanarBuffer:destination:)](accelerate/vimage/pixelbuffer/overwritechannels(_:withplanarbuffer:destination:)-9jbky.md)
- [overwriteChannels(_:withPlanarBuffer:destination:)](accelerate/vimage/pixelbuffer/overwritechannels(_:withplanarbuffer:destination:)-hiw0.md)
- [overwriteChannels(_:withInterleavedBuffer:destination:)](accelerate/vimage/pixelbuffer/overwritechannels(_:withinterleavedbuffer:destination:)-74hah.md)
- [overwriteChannels(_:withInterleavedBuffer:destination:)](accelerate/vimage/pixelbuffer/overwritechannels(_:withinterleavedbuffer:destination:)-8xkd1.md)