---
title: "multiply(by:divisor:preBias:postBias:destination:)"
framework: accelerate
role: symbol
role_heading: Instance Method
path: "accelerate/vimage/pixelbuffer/multiply(by:divisor:prebias:postbias:destination:)-7jo6v"
---

# multiply(by:divisor:preBias:postBias:destination:)

Multiplies each pixel in an 8-bit planar pixel buffer by the specified factor.

## Declaration

```swift
func multiply(by factor: Int, divisor: Int, preBias: Int, postBias: Int, destination: vImage.PixelBuffer<vImage.Planar8>)
```

## Parameters

- `factor`: The multiplication factor.
- `divisor`: A value that the function divides the result by. The function treats 0 as 1.
- `preBias`: A value that the function adds to the source before multiplication.
- `postBias`: A value that the function adds to the result after multiplication.
- `destination`: The destination pixel buffer.

## Discussion

Discussion This function applies the following operation to each pixel: destination = (((source + preBias) * factor) + postBias) / divisor For example, the following code multiplies each pixel value in an 8-bit planar buffer by 2 and adds 5:   let buffer = vImage.PixelBuffer<vImage.Planar8>(        pixelValues: [10, 20, 30, 40,                      50, 60, 70, 80],        size: vImage.Size(width: 4,                          height: 2))

buffer.multiply(by: 2,                    divisor: 1,                    preBias: 0, postBias: 5,                    destination: buffer)

// Prints    // [  25,  45,  65,  85,    //   105, 125, 145, 165 ]    print(buffer.array)

## See Also

### Scalar Multiplication

- [multiply(by:preBias:postBias:destination:)](accelerate/vimage/pixelbuffer/multiply(by:prebias:postbias:destination:)-3bh2a.md)