CCITT在Swift中的实现

import UIKit
import ImageIO
import CoreGraphics

func convertImageToJPEG(from image: UIImage) -> Data? {
    guard let cgImage = image.cgImage else { return nil }
    
    let colorSpace = CGColorSpaceCreateDeviceRGB()
    let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.noneSkipFirst.rawValue)
    guard let context = CGContext(data: nil, width: cgImage.width, height: cgImage.height, bitsPerComponent: 8, bytesPerRow: cgImage.width * 4, space: colorSpace, bitmapInfo: bitmapInfo.rawValue),
          let cgImageRef = context.makeImage() else { return nil }
    
    context.draw(cgImage, in: CGRect(x: 0, y: 0, width: cgImage.width, height: cgImage.height))
    
    guard let dataProvider = CGDataProvider(data: context.data),
          let jpegData = CGImageDestinationCreateWithData(dataProvider, kUTTypeJPEG as CFString, 1, nil) else { return nil }
    
    CGImageDestinationAddImage(jpegData, cgImageRef, nil)
    CGImageDestinationFinalize(jpegData)
    
    return jpegData.data
}