uiimage-extension-resize-pixelbuffer.swift

extension UIImage{
func resize(newSize: CGSize) -> UIImage? {
        UIGraphicsBeginImageContextWithOptions(newSize, false, 0.0)
        self.draw(in: CGRect(x: 0, y: 0, width: newSize.width, height: newSize.height))
        let newImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return newImage
    }
    
    
    func toCVPixelBuffer() -> CVPixelBuffer? {
       var pixelBuffer: CVPixelBuffer? = nil
let attr = [kCVPixelBufferCGImageCompatibilityKey: kCFBooleanTrue,
        kCVPixelBufferCGBitmapContextCompatibilityKey: kCFBooleanTrue] as CFDictionary
        
       let width = Int(self.size.width)
       let height = Int(self.size.height)
CVPixelBufferCreate(kCFAllocatorDefault, width, height, kCVPixelFormatType_OneComponent8, attr, &pixelBuffer)
       CVPixelBufferLockBaseAddress(pixelBuffer!, CVPixelBufferLockFlags(rawValue:0))
let colorspace = CGColorSpaceCreateDeviceGray()
       let bitmapContext = CGContext(data: CVPixelBufferGetBaseAddress(pixelBuffer!), width: width, height: height, bitsPerComponent: 8, bytesPerRow: CVPixelBufferGetBytesPerRow(pixelBuffer!), space: colorspace, bitmapInfo: 0)!
guard let cg = self.cgImage else {
           return nil
       }
bitmapContext.draw(cg, in: CGRect(x: 0, y: 0, width: width, height: height))
return pixelBuffer
    }
}