Android中按比例缩放图片以减少内存消耗 解决oom有关问题

Android中按比例缩放图片以减少内存消耗 解决oom问题

// decode这个图片并且按比例缩放以减少内存消耗，虚拟机对每张图片的缓存大小也是有限制的
 private Bitmap decodeFile(File f) {
  try {
   // decode image size
   BitmapFactory.Options o = new BitmapFactory.Options();
   o.inJustDecodeBounds = true;
   BitmapFactory.decodeStream(new FileInputStream(f), null, o);

   // Find the correct scale value. It should be the power of 2.
   final int REQUIRED_SIZE = 100;
   int width_tmp = o.outWidth, height_tmp = o.outHeight;
   int scale = 1;
   while (true) {
    if (width_tmp / 2 < REQUIRED_SIZE
      || height_tmp / 2 < REQUIRED_SIZE)
     break;
    width_tmp /= 2;
    height_tmp /= 2;
    scale *= 2;
   }

   // decode with inSampleSize
   BitmapFactory.Options o2 = new BitmapFactory.Options();
   o2.inSampleSize = scale;
   return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
  } catch (FileNotFoundException e) {
  }
  return null;
 }