如何在Google Earth Engine中提高导出图像的分辨率？

Question

我有一些代码可以使用GEE将LS8图像导出到云端硬盘。不知何故，图像的分辨率似乎比我在浏览器中看到的要低（较大的像素）。如何提高分辨率？这是我一直在使用的代码，有两个不同的选项。

我尝试使用.resample()作为解决方案，但它产生的单波段图像看起来不太好。

     geometry2 = /* color: #57d64b */ee.Geometry.Polygon(
        [[[-78.2812086867645, 2.3386717366200585],
          [-77.56984394067075, 2.3729749945579948],
          [-77.72227924340513, 2.776314152654142],
          [-78.20842426293638, 2.725560942159387]]]);

    function maskL8sr(image)

 {
      // Bits 3 and 5 are cloud shadow and cloud, respectively.
      var cloudShadowBitMask = ee.Number(2).pow(3).int();
      var cloudsBitMask = ee.Number(2).pow(5).int();

      // Get the pixel QA band.
      var qa = image.select('pixel_qa');

      // Both flags should be set to zero, indicating clear conditions.
      var mask = qa.bitwiseAnd(cloudShadowBitMask).eq(0)
          .and(qa.bitwiseAnd(cloudsBitMask).eq(0));

      // Return the masked image, scaled to TOA reflectance, without the QA bands.
      return image.updateMask(mask).divide(10000)
          .select("B[0-9]*")
          .copyProperties(image, ["system:time_start"]);
    }

    // Map the function over one year of data.
    var collection = ee.ImageCollection('LANDSAT/LC08/C01/T1_SR')
        .filterDate('2016-04-01', '2018-7-31')
        .map(maskL8sr)

    var composite = collection.median();

    var VIS = {bands: ['B5', 'B6', 'B4'], min: 0, max: 0.47};

    // Display the results.
    Map.addLayer(composite,VIS ,"compt2");




    var params ={
          crs: 'EPSG:4326',
          maxPixels: 1e12,
          region:geometry2
        }

    Export.image(composite,'Guapi',params);

    Export.image.toDrive({
      image: composite,
      description: 'Guapi',
      scale: 30,
      region: geometry2,
      maxPixels: 1000000000
    });