/**Bitmap放大的方法*/

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,0,0,bitmap.getWidth(),bitmap.getHeight(),matrix,true); 
    return resizeBmp; 
  }

/**Bitmap缩小的方法*/

  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,0,0,bitmap.getWidth(),bitmap.getHeight(),matrix,true); 
    return resizeBmp; 
  }