等比例缩放图片

/ 缩放图片

public static Bitmap zoomImg(String img, int newWidth ,int newHeight){

// 图片源

   Bitmap bm = BitmapFactory.decodeFile(img);

   if(null!=bm){

   
 return zoomImg(bm,newWidth,newHeight);

   }

   return null;

}


public static Bitmap zoomImg(Context context,String img, int newWidth ,int newHeight){

// 图片源

try {

Bitmap bm = BitmapFactory.decodeStream(context.getAssets()

.open(img));

if (null != bm) {

return zoomImg(bm, newWidth, newHeight);

}

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

return null;

}

// 缩放图片

public static Bitmap zoomImg(Bitmap bm, int newWidth ,int newHeight){

   // 获得图片的宽高

   int width = bm.getWidth();

   int height = bm.getHeight();

   // 计算缩放比例

   float scaleWidth = ((float) newWidth) / width;

   float scaleHeight = ((float) newHeight) / height;

   // 取得想要缩放的matrix参数

   Matrix matrix = new Matrix();

   matrix.postScale(scaleWidth, scaleHeight);

   // 得到新的图片

   Bitmap newbm = Bitmap.createBitmap(bm, 0, 0, width, height, matrix, true);

     
return newbm;

}