Android - 几种保存成jpeg文件的模式

//1.采用NV21格式 YuvImage类进行保存   效率很高String fileName = "IMG_"       + String.valueOf(index) + ".jpg";File sdRoot = Environment.getExternalStorageDirectory();String dir = "/picture/";File mkDir = new File(sdRoot, dir);if (!mkDir.exists()){   mkDir.mkdirs();}File pictureFile = new File(sdRoot, dir + fileName);if (!pictureFile.exists()) {   try {       pictureFile.createNewFile();       FileOutputStream filecon = new FileOutputStream(pictureFile);       YuvImage image = new YuvImage(data,               ImageFormat.NV21, size.width, size.height,               null);       image.compressToJpeg(               new Rect(0, 0, image.getWidth(), image.getHeight()),               70, filecon);   // 将NV21格式图片，以质量70压缩成Jpeg，并得到JPEG数据流   }catch (IOException e)   {       e.printStackTrace();   }}//2.采用Bitmap类Bitmap bmp = BitmapFactory.decodeFile(pictureFile.getPath());FileOutputStream fileOutStream = null;fileOutStream = new FileOutputStream(file);bmp.compress(Bitmap.CompressFormat.JPEG, 100, fileOutStream);  //把位图输出到指定的文件中fileOutStream.flush();fileOutStream.close();//3.直接采用保存byte[]数据FileOutputStream fos = new FileOutputStream(pictureFile.getPath()); // Get file output streamfos.write(bytes);                                               // Written to the filefos.close();