一种通过matrix矩阵缩放：

//使用Bitmap加Matrix来缩放    public static Drawable resizeImage(Bitmap bitmap, int w, int h)     {          Bitmap BitmapOrg = bitmap;          int width = BitmapOrg.getWidth();          int height = BitmapOrg.getHeight();          int newWidth = w;          int newHeight = h;           float scaleWidth = ((float) newWidth) / width;          float scaleHeight = ((float) newHeight) / height;           Matrix matrix = new Matrix();          matrix.postScale(scaleWidth, scaleHeight);          // if you want to rotate the Bitmap           // matrix.postRotate(45);           Bitmap resizedBitmap = Bitmap.createBitmap(BitmapOrg, 0, 0, width,                          height, matrix, true);          return new BitmapDrawable(resizedBitmap);      }

 

另一种，通过设置BitmapFactory.Options的inSampleSize参数来缩放

//使用BitmapFactory.Options的inSampleSize参数来缩放    public static Drawable resizeImage2(String path,            int width,int height)     {        BitmapFactory.Options options = new BitmapFactory.Options();        options.inJustDecodeBounds = true;//不加载bitmap到内存中        BitmapFactory.decodeFile(path,options);         int outWidth = options.outWidth;        int outHeight = options.outHeight;        options.inDither = false;        options.inPreferredConfig = Bitmap.Config.ARGB_8888;        options.inSampleSize = 1;                 if (outWidth != 0 && outHeight != 0 && width != 0 && height != 0)         {            int sampleSize=(outWidth/width+outHeight/height)/2;            Log.d(tag, "sampleSize = " + sampleSize);            options.inSampleSize = sampleSize;        }             options.inJustDecodeBounds = false;        return new BitmapDrawable(BitmapFactory.decodeFile(path, options));         }