创建bitmap另一种方式

Bitmap target = Bitmap.createBitmap(size, size, getConfig(bitmap));
       int width = Math.round(scale * bitmap.getWidth());
       int height = Math.round(scale * bitmap.getHeight());
       Canvas canvas = new Canvas(target);
       canvas.translate((size - width) / 2f, (size - height) / 2f);//偏移，也可以旋转之类操作
       canvas.scale(scale, scale);
       Paint paint = new Paint(Paint.FILTER_BITMAP_FLAG | Paint.DITHER_FLAG);
       canvas.drawBitmap(bitmap, 0, 0, paint);