vision-segmentation-maskInputImage.swift

func maskInputImage(_ buffer: CVPixelBuffer){
        
        let bgImage = UIImage(named: "background")!
        
        let input = CIImage(cgImage: inputImage.cgImage!)
        let mask = CIImage(cvPixelBuffer: buffer)
        let background = CIImage(cgImage: bgImage.cgImage!)
        
        let maskScaleX = input.extent.width / mask.extent.width
        let maskScaleY = input.extent.height / mask.extent.height
        
        let maskScaled =  mask.transformed(by: __CGAffineTransformMake(maskScaleX, 0, 0, maskScaleY, 0, 0))
        
        let backgroundScaleX = input.extent.width / background.extent.width
        let backgroundScaleY = input.extent.height / background.extent.height
        
        let backgroundScaled =  background.transformed(by: __CGAffineTransformMake(backgroundScaleX, 0, 0, backgroundScaleY, 0, 0))
        
        
        let blendFilter = CIFilter.blendWithMask()
        
        blendFilter.inputImage = input
        blendFilter.backgroundImage = backgroundScaled
        blendFilter.maskImage = maskScaled

        if let blendedImage = blendFilter.outputImage{
        
            let ciContext = CIContext(options: nil)
            let filteredImageRef = ciContext.createCGImage(blendedImage, from: blendedImage.extent)
            let maskDisplayRef = ciContext.createCGImage(maskScaled, from: maskScaled.extent)
            
            self.outputImage = UIImage(cgImage: maskDisplayRef!)
            self.finalOutputImage = UIImage(cgImage: filteredImageRef!)
            
        }
}