encode image to bitmap black and transparent

ImageEncoder

import android.graphics.Bitmap

import com.google.zxing.BarcodeFormat
import com.google.zxing.MultiFormatWriter
import com.google.zxing.common.BitMatrix

/**
 * Created by ilham on 9/19/17.
 */

class ImageEncoder {

    companion object {
        fun createBitmapImage(id: String?): Bitmap {
            val formatWriter = MultiFormatWriter()
            val bitMatrix = formatWriter.encode(id, BarcodeFormat.QR_CODE, 280, 280)

            fun createBitmap(matrix: BitMatrix): Bitmap {
                val transparent = 0x00FFFFFF
                val black = -0x1000000

                val height = matrix.height
                val width = matrix.width
                val bmp = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565)
                for (x in 0 until width) {
                    for (y in 0 until height) {
                        bmp.setPixel(x, y, if (matrix.get(x, y)) black else transparent)
                    }
                }
                return bmp
            }

            return createBitmap(bitMatrix)
        }
    }
}