Android 截取图片正中间

    /** 
                                                                           
       * @param bitmap      原图 
       * @param edgeLength  希望得到的正方形部分的边长 
       * @return  缩放截取正中部分后的位图。 
       */  
      public static Bitmap centerSquareScaleBitmap(Bitmap bitmap,int edgeLength)  
      {  
       if(null == bitmap || edgeLength <= 0)  
       {  
        return  null;  
       }  
                                                                                       
       Bitmap result = bitmap;  
       int widthOrg = bitmap.getWidth();  
       int heightOrg = bitmap.getHeight();  
                                                                                       
       if(widthOrg > edgeLength && heightOrg > edgeLength)  
       {  
        //压缩到一个最小长度是edgeLength的bitmap  
        int longerEdge = (int)(edgeLength * Math.max(widthOrg,heightOrg) / Math.min(widthOrg,heightOrg));  
        int scaledWidth = widthOrg > heightOrg ? longerEdge : edgeLength;  
        int scaledHeight = widthOrg > heightOrg ? edgeLength : longerEdge;  
        Bitmap scaledBitmap;  
                                                                                        
              try{  
               scaledBitmap = Bitmap.createScaledBitmap(bitmap,scaledWidth,scaledHeight,true);  
              }  
              catch(Exception e){  
               return null;  
              }  
                                                                                             
           //从图中截取正中间的正方形部分。  
           int xTopLeft = (scaledWidth - edgeLength) / 2;  
           int yTopLeft = (scaledHeight - edgeLength) / 2;  
                                                                                           
           try{  
            result = Bitmap.createBitmap(scaledBitmap,xTopLeft,yTopLeft,edgeLength,edgeLength);  
            scaledBitmap.recycle();  
           }  
           catch(Exception e){  
            return null;  
           }         
       }  
                                                                                            
       return result;  
      }