android bitmap的放大缩小

 private static Bitmap big(Bitmap bitmap) {
   Matrix matrix = new Matrix();
   matrix.postScale(1.5f,1.5f); //长和宽放大缩小的比例
   Bitmap resizeBmp = Bitmap.createBitmap(bitmap,,,bitmap.getWidth(),bitmap.getHeight(),matrix,true);
   return resizeBmp;
  }

  private static Bitmap small(Bitmap bitmap) {
   Matrix matrix = new Matrix();
   matrix.postScale(0.8f,0.8f); //长和宽放大缩小的比例
   Bitmap resizeBmp = Bitmap.createBitmap(bitmap,,,bitmap.getWidth(),bitmap.getHeight(),matrix,true);
   return resizeBmp;
  }