Сжатие изображения на iPhone как в whatsapp

I'm trying to find an image compression algorithm in the Swift programming language, as in the WhatsApp messenger. In the programming language Java under OS Android I found quickly, and under the platform iOS have difficulties.

Here is the image compression algorithm for Android:

public static File saveBitmapToFile(File file){
    try {
        // BitmapFactory options to downsize the image
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        o.inSampleSize = 6;
        // factor of downsizing the image

        FileInputStream inputStream = new FileInputStream(file);
        //Bitmap selectedBitmap = null;
        BitmapFactory.decodeStream(inputStream, null, o);
        inputStream.close();

        // The new size we want to scale to
        final int REQUIRED_SIZE=75;

        // Find the correct scale value. It should be the power of 2.
        int scale = 1;
        while(o.outWidth / scale / 2 >= REQUIRED_SIZE &&
                o.outHeight / scale / 2 >= REQUIRED_SIZE) {
            scale *= 2;
        }

        BitmapFactory.Options o2 = new BitmapFactory.Options();
        o2.inSampleSize = scale;
        inputStream = new FileInputStream(file);

        Bitmap selectedBitmap = BitmapFactory.decodeStream(inputStream, null, o2);
        inputStream.close();

        // here i override the original image file
        file.createNewFile();
        FileOutputStream outputStream = new FileOutputStream(file);

        selectedBitmap.compress(Bitmap.CompressFormat.JPEG, 70 , outputStream);

        return file;
    } catch (Exception e) {
        return null;
    }
}

This algorithm compresses the image to 100 KB. If you can tell me how to duplicate this code into the Swift programming language, I'll be very grateful.

I have studied many articles, tried to use different algorithms (unfortunately I can not publish them, because I do not remember the sites), but I did not find the necessary solution.