code: function partial(area) {
      var allFilter = null;
  
      for (var _len2 = arguments.length, filters = Array(_len2 > 1 ? _len2 - 1 : 0), _key2 = 1; _key2 < _len2; _key2++) {
          filters[_key2 - 1] = arguments[_key2];
      }
  
      if (filters.length == 1 && typeof filters[0] === 'string') {
          allFilter = filter$1(filters[0]);
      } else {
          allFilter = merge$1(filters);
      }
  
      return function (bitmap, done) {
          var opt = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : {};
  
          allFilter(getBitmap(bitmap, area), function (newBitmap) {
              done(putBitmap(bitmap, newBitmap, area));
          }, opt);
      };
  }
docs: apply filter into special area
  
  F.partial({x,y,width,height}, filter, filter, filter )
  F.partial({x,y,width,height}, 'filter' )
  
  @param {{x, y, width, height}} area
  @param {*} filters