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ee.Image.firstNonZero
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。
如果第一个值不为零，则选择第一个值；否则，选择第二个值（针对 image1 和 image2 中的每个匹配波段对）。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。输出像素的类型是输入类型的并集。
| 用法 | 返回 |
|---|
Image.firstNonZero(image2) | 图片 |
| 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。 |
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最后更新时间 (UTC)：2025-07-26。
[null,null,["最后更新时间 (UTC)：2025-07-26。"],[[["\u003cp\u003eSelects the first image's band value if non-zero, otherwise selects the second image's band value, comparing bands pairwise.\u003c/p\u003e\n"],["\u003cp\u003eIf one image has a single band, it's compared against all bands of the other image.\u003c/p\u003e\n"],["\u003cp\u003eOutput bands are named using the longer image's band names, or the first image's if band counts are equal.\u003c/p\u003e\n"],["\u003cp\u003eOutput pixel type is determined by combining the input pixel types to accommodate all possible values.\u003c/p\u003e\n"]]],["The operation compares paired bands from two images, `image1` and `image2`. For each pair, it selects the first non-zero value. If one image has a single band, that band is used against all bands of the other. If band names differ but counts match, they are matched in order. Output bands are named after the longer input or `image1` if lengths are equal, with the output pixel type being a union of input types. The operation returns an `Image`.\n"],null,["# ee.Image.firstNonZero\n\nSelects the first value if it is non-zero, and the second value otherwise 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 the union of the input types.\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|------------------------------|---------|\n| Image.firstNonZero`(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. |"]]
