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gee——影像无法正常加载和影像下载后数据异常

此星光明发表于 2022/11/24 23:23:18 2022/11/24

【摘要】当我们下载或者展示影像的时候会出现错误，本文主要解决两个问题，第一个就是解决影像展示的问题，展示如果不能正常显示影像的RGB影像，一般情况下主要出现的问题就在于最大值和最小值的设定，如果你不知道该如何设置，就直接去掉min和max的设置。这样也能正常显示，Map.addLayer(eeObject, visParams, name, shown, opacity)Adds a given ...

当我们下载或者展示影像的时候会出现错误，本文主要解决两个问题，第一个就是解决影像展示的问题，展示如果不能正常显示影像的RGB影像，一般情况下主要出现的问题就在于最大值和最小值的设定，如果你不知道该如何设置，就直接去掉min和max的设置。这样也能正常显示，

Map.addLayer(eeObject, visParams, name, shown, opacity)

Adds a given EE object to the map as a layer.

Returns the new map layer.

Arguments:

eeObject (Collection|Feature|Image|RawMapId):

The object to add to the map.

visParams (FeatureVisualizationParameters|ImageVisualizationParameters, optional):

The visualization parameters. For Images and ImageCollection, see ee.data.getMapId for valid parameters. For Features and FeatureCollections, the only supported key is "color", as a CSS 3.0 color string or a hex string in "RRGGBB" format. Ignored when eeObject is a map ID.

name (String, optional):

The name of the layer. Defaults to "Layer N".

shown (Boolean, optional):

A flag indicating whether the layer should be on by default.

opacity (Number, optional):

The layer's opacity represented as a number between 0 and 1. Defaults to 1.

Returns: ui.Map.Layer

原始代码：

var roi = 
    /* color: #d63000 */
    /* displayProperties: [
      {
        "type": "rectangle"
      }
    ] */
    ee.Geometry.Polygon(
        [[[30.335363045782245, -22.81645461186883],
          [30.335363045782245, -23.114862567618875],
          [30.74597705945412, -23.114862567618875],
          [30.74597705945412, -22.81645461186883]]], null, false);

// Exporting Lansat 8 images

// Load Landsat 8 
var image= ee.ImageCollection("LANDSAT/LC08/C02/T1_L2")
.filterDate("2017-01-01", "2017-12-31")
.filterBounds(roi)
.sort("CLOUD_COVER")
.first();

var vispaaramsTrue = {bands: ["SR_B4", "SR_B3", "SR_B2"], min: 0, max: 3000, gamma:1.4};
Map.addLayer(image.clip(roi), vispaaramsTrue, "Landsat 2017");
Map.centerObject(roi, 10);

// Export to drive
Export.image.toDrive({
image: image,
description: "Landsat2017Thohoyandou",
scale: 30,
region: roi,
maxPixels: 1e13
});

修改后的代码：

// Exporting Lansat 8 images

// Load Landsat 8 
var image= ee.ImageCollection("LANDSAT/LC08/C02/T1_L2")
.filterDate("2017-01-01", "2017-12-31")
.filterBounds(roi)
.sort("CLOUD_COVER")
.first();

print(image)

var vispaaramsTrue = {bands: ["SR_B4", "SR_B3", "SR_B2"], min: 5000, max: 15000};
Map.addLayer(image.clip(roi), vispaaramsTrue, "Landsat 2017");
Map.centerObject(roi, 10);

// Export to drive
Export.image.toDrive({
image: image,
description: "Landsat2017Thohoyandou",
scale: 30,
region: roi,
maxPixels: 1e13
});