copy(to:cvImageFormat:cgImageFormat:)
Copies the contents of a pixel buffer to a Core Video pixel buffer.
Declaration
func copy(to cvPixelBuffer: CVPixelBuffer, cvImageFormat: vImageCVImageFormat, cgImageFormat: vImage_CGImageFormat) throwsParameters
- cvPixelBuffer:
The destination Core Video pixel buffer.
- cvImageFormat:
A Vimagecvimageformat that specifies the pixel format of the destination buffer.
- cgImageFormat:
The Core Graphics format of the source buffer.
Discussion
The destination Core Video pixel buffer must be nonplanar and be the same size as the source buffer.
The following code shows how to incorporate a vImage pixel buffer into a CIImageProcessorKernel instance. The code calls copy(to:cvImageFormat:cgImageFormat:) to write the result of a contast stretch operation to the processor kernel’s output.
class ContrastStretchImageProcessorKernel: CIImageProcessorKernel {
static var cgImageFormat = vImage_CGImageFormat(
bitsPerComponent: 8,
bitsPerPixel: 32,
colorSpace: CGColorSpaceCreateDeviceRGB(),
bitmapInfo: CGBitmapInfo(rawValue: CGImageAlphaInfo.noneSkipLast.rawValue),
renderingIntent: .defaultIntent)!
static let cvImageFormat = vImageCVImageFormat.make(
format: .format32BGRA,
colorSpace: CGColorSpaceCreateDeviceRGB(),
alphaIsOpaqueHint: true)!
override class var outputFormat: CIFormat {
return CIFormat.BGRA8
}
override class func formatForInput(at input: Int32) -> CIFormat {
return CIFormat.BGRA8
}
override class func process(with inputs: [CIImageProcessorInput]?,
arguments: [String: Any]?,
output: CIImageProcessorOutput) throws {
guard
let input = inputs?.first,
let inputPixelBuffer = input.pixelBuffer,
let outputPixelBuffer = output.pixelBuffer else {
return
}
let buffer = try vImage.PixelBuffer(copying: inputPixelBuffer,
cvImageFormat: cvImageFormat,
cgImageFormat: &cgImageFormat,
pixelFormat: vImage.Interleaved8x4.self)
buffer.contrastStretch(destination: buffer)
try buffer.copy(to: outputPixelBuffer,
cvImageFormat: cvImageFormat,
cgImageFormat: cgImageFormat)
}
}