# Applying arithmetic operations Multiply the pixel values of a buffer by scalar values or matrices. ## Topics ### Scalar Multiplication [`func multiply(by: Int, divisor: Int, preBias: Int, postBias: Int, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/multiply(by:divisor:preBias:postBias:destination:)-7jo6v) Multiplies each pixel in an 8-bit planar pixel buffer by the specified factor. [`func multiply(by: Float, preBias: Float, postBias: Float, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/multiply(by:preBias:postBias:destination:)-3bh2a) Multiplies each pixel in a 32-bit planar pixel buffer by the specified factor. ### Matrix Multiplication [`func multiply(by: Matrix, divisor: Int, preBias: (Int, Int, Int, Int), postBias: (Int, Int, Int, Int), destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/multiply(by:divisor:preBias:postBias:destination:)-7ikb7) Multiplies each four channel pixel in an 8-bit-per channel, 4-channel pixel buffer by a 4 x 4 matrix to produce a four channel result. [`func multiply(by: Matrix, preBias: (Float, Float, Float, Float), postBias: (Float, Float, Float, Float), destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/multiply(by:preBias:postBias:destination:)-5tm47) Multiplies each four channel pixel in a 32-bit-per channel, 4-channel pixel buffer by a 4 x 4 matrix to produce a four channel result. [`func multiply(by: simd_float4x4, preBias: (Float, Float, Float, Float), postBias: (Float, Float, Float, Float), destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/multiply(by:preBias:postBias:destination:)-5tq68) Multiplies each four channel pixel in a 32-bit-per channel, 4-channel pixel buffer by a 4 x 4 simd matrix to produce a four channel result. [`func multiply(by: Matrix, divisor: Int, preBias: [Int], postBias: [Int], destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/multiply(by:divisor:preBias:postBias:destination:)-86hbw) Multiplies each four channel pixel in an 8-bit multiple-plane pixel buffer by a 4 x 4 matrix to produce a four channel result. [`func multiply(by: Matrix, preBias: [Float], postBias: [Float], destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/multiply(by:preBias:postBias:destination:)-3kltz) Multiplies each four channel pixel in a 32-bit multiple-plane pixel buffer by a 4 x 4 matrix to produce a four channel result. ### Pixel Multiplication [`func multiply(by: (Int, Int, Int, Int), divisor: Int, preBias: (Int, Int, Int, Int), postBias: Int, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/multiply(by:divisor:preBias:postBias:destination:)-4q614) Multiplies each four channel pixel in an 8-bit-per channel, 4-channel pixel buffer by a four element matrix to produce a single channel result. [`func multiply(by: (Float, Float, Float, Float), preBias: (Float, Float, Float, Float), postBias: Float, destination: vImage.PixelBuffer)`](/documentation/Accelerate/vImage/PixelBuffer/multiply(by:preBias:postBias:destination:)-1sp5l) Multiplies each four channel pixel in a 32-bit-per channel, 4-channel pixel buffer by a four element matrix to produce a single channel result. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)