将UIImage转换为单色1位bmp图像Swift 5.1

import UIKit

func convertImageTo1BitBMP(image: UIImage) -> Data? {
    guard let cgImage = image.cgImage else {
        return nil
    }
    
    let width = cgImage.width
    let height = cgImage.height
    
    let colorSpace = CGColorSpaceCreateDeviceGray()
    let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.none.rawValue)
    
    guard let context = CGContext(data: nil, width: width, height: height, bitsPerComponent: 1, bytesPerRow: width/8, space: colorSpace, bitmapInfo: bitmapInfo.rawValue) else {
        return nil
    }
    
    let rect = CGRect(x: 0, y: 0, width: width, height: height)
    context.draw(cgImage, in: rect)
    
    guard let bitmapData = context.data else {
        return nil
    }
    
    let dataSize = width * height / 8
    let data = Data(bytes: bitmapData, count: dataSize)
    
    return data
}

// 使用示例
let image = UIImage(named: "example_image")
if let imageData = convertImageTo1BitBMP(image: image) {
    // 保存为bmp文件
    let fileURL = URL(fileURLWithPath: "path_to_save_bmp_file.bmp")
    do {
        try imageData.write(to: fileURL)
        print("转换成功，bmp文件保存在：\(fileURL)")
    } catch {
        print("保存bmp文件失败：\(error)")
    }
}