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ee.Image.gt
使用集合让一切井井有条
根据您的偏好保存内容并对其进行分类。
当且仅当 image1 和 image2 中每个匹配的波段对的第一个值大于第二个值时,返回 1。如果 image1 或 image2 只有一个波段,则会将其与另一张图片中的所有波段进行比较。如果图片具有相同数量的波段,但名称不同,则会按自然顺序成对使用。输出波段的命名方式为:如果两个输入的长度不同,则以较长的输入命名;如果长度相同,则以 image1 的顺序命名。输出像素的类型为布尔值。
参数 | 类型 | 详细信息 |
---|
此:image1 | 图片 | 从中获取左操作数波段的映像。 |
image2 | 图片 | 从中获取右操作数波段的映像。 |
示例
代码编辑器 (JavaScript)
// Show world oceans in blue and anything higher than the ellipsoid as gray.
// The bedrock layer is generally close to the geoid (sealevel).
var elevation = ee.Image('NOAA/NGDC/ETOPO1').select('bedrock');
var waterLand = elevation.gt(0.0);
var waterLandViz = {palette: ['cadetblue', 'lightgray']};
Map.addLayer(waterLand, waterLandViz, 'water_land');
Python 设置
如需了解 Python API 和如何使用 geemap
进行交互式开发,请参阅
Python 环境页面。
import ee
import geemap.core as geemap
Colab (Python)
# Show world oceans in blue and anything higher than the ellipsoid as gray.
# The bedrock layer is generally close to the geoid (sealevel).
elevation = ee.Image('NOAA/NGDC/ETOPO1').select('bedrock')
water_land = elevation.gt(0.0)
water_land_viz = {'palette': ['cadetblue', 'lightgray']}
m = geemap.Map()
m.add_layer(water_land, water_land_viz, 'water_land')
m
如未另行说明,那么本页面中的内容已根据知识共享署名 4.0 许可获得了许可,并且代码示例已根据 Apache 2.0 许可获得了许可。有关详情,请参阅 Google 开发者网站政策。Java 是 Oracle 和/或其关联公司的注册商标。
最后更新时间 (UTC):2025-07-26。
[null,null,["最后更新时间 (UTC):2025-07-26。"],[[["\u003cp\u003eThe \u003ccode\u003egt()\u003c/code\u003e function compares corresponding bands of two images, returning 1 if the first image's band value is greater than the second image's band value, and 0 otherwise.\u003c/p\u003e\n"],["\u003cp\u003eIf the images have different numbers of bands, single-band images are compared against all bands of the multi-band image; if they have the same number of bands but different names, bands are compared in their natural order.\u003c/p\u003e\n"],["\u003cp\u003eThe output is a boolean image with bands named according to the longer input image or, if equal in length, the first image's band names.\u003c/p\u003e\n"],["\u003cp\u003eThis function is useful for creating binary masks based on thresholding, such as identifying areas above sea level in an elevation dataset.\u003c/p\u003e\n"]]],["The function compares corresponding bands between two images (`image1` and `image2`). It returns 1 (true) if `image1`'s band value is greater than `image2`'s; otherwise, it returns 0 (false). If one image has a single band, it's compared against all bands of the other image. If the images have the same amount of bands with differing names, bands are compared sequentially. The output, representing these comparisons, is an image with boolean pixel values, named according to the longer input image's band names, or `image1`'s if they have the same length.\n"],null,["# ee.Image.gt\n\nReturns 1 if and only if the first value is greater than the second for each matched pair of bands in image1 and image2. If either image1 or image2 has only 1 band, then it is used against all the bands in the other image. If the images have the same number of bands, but not the same names, they're used pairwise in the natural order. The output bands are named for the longer of the two inputs, or if they're equal in length, in image1's order. The type of the output pixels is boolean.\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|--------------------|---------|\n| Image.gt`(image2)` | Image |\n\n| Argument | Type | Details |\n|----------------|-------|---------------------------------------------------------|\n| this: `image1` | Image | The image from which the left operand bands are taken. |\n| `image2` | Image | The image from which the right operand bands are taken. |\n\nExamples\n--------\n\n### Code Editor (JavaScript)\n\n```javascript\n// Show world oceans in blue and anything higher than the ellipsoid as gray.\n// The bedrock layer is generally close to the geoid (sealevel).\nvar elevation = ee.Image('NOAA/NGDC/ETOPO1').select('bedrock');\nvar waterLand = elevation.gt(0.0);\nvar waterLandViz = {palette: ['cadetblue', 'lightgray']};\nMap.addLayer(waterLand, waterLandViz, 'water_land');\n```\nPython setup\n\nSee the [Python Environment](/earth-engine/guides/python_install) page for information on the Python API and using\n`geemap` for interactive development. \n\n```python\nimport ee\nimport geemap.core as geemap\n```\n\n### Colab (Python)\n\n```python\n# Show world oceans in blue and anything higher than the ellipsoid as gray.\n# The bedrock layer is generally close to the geoid (sealevel).\nelevation = ee.Image('NOAA/NGDC/ETOPO1').select('bedrock')\nwater_land = elevation.gt(0.0)\nwater_land_viz = {'palette': ['cadetblue', 'lightgray']}\nm = geemap.Map()\nm.add_layer(water_land, water_land_viz, 'water_land')\nm\n```"]]