multiply(by:divisor:preBias:postBias:destination:)
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.
Declaration
func multiply<Matrix>(by matrix: Matrix, divisor: Int, preBias: (Int, Int, Int, Int), postBias: (Int, Int, Int, Int), destination: vImage.PixelBuffer<vImage.Interleaved8x4>) where Matrix : AccelerateBuffer, Matrix.Element == IntParameters
- matrix:
The 4 x 4 multiplication matrix values in row-major order.
- divisor:
A value that the function divides the result by.
- preBias:
Values 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
This function applies the following operation to each pixel:
p = (source.0 + preBias.0) * matrix.0 +
(source.1 + preBias.1) * matrix.1 +
(source.2 + preBias.2) * matrix.2 +
(source.3 + preBias.3) * matrix.3
destination = (p + postBias) / divisor