公告:凡是在
2025 年 4 月 15 日前註冊使用 Earth Engine 的非商業專案,都必須
驗證非商業用途資格,才能繼續存取 Earth Engine。
ee.Number.byte
透過集合功能整理內容
你可以依據偏好儲存及分類內容。
將輸入值轉換為無正負號的 8 位元整數。
範例
程式碼編輯器 (JavaScript)
// Cast a number to unsigned 8-bit integer: [0, 255].
var number = ee.Number(100);
print('Number:', number);
var byteNumber = number.byte();
print('Number cast to byte:', byteNumber);
/**
* Casting numbers to byte that are outside of its range and precision can
* modify the resulting value, note the behavior of the following scenarios.
*/
// A floating point number cast to byte loses decimal precision.
var float = ee.Number(1.7);
print('Floating point value:', float);
var floatToByte = float.byte();
print('Floating point value cast to byte:', floatToByte);
// A number greater than byte range max cast to byte becomes byte range max.
var BYTE_MAX = 255;
var outOfRangeHi = ee.Number(BYTE_MAX + 12345);
print('Greater than byte max:', outOfRangeHi);
var outOfRangeHiToByte = outOfRangeHi.byte();
print('Greater than byte max cast to byte becomes byte max:', outOfRangeHiToByte);
// A number greater than byte range min cast to byte becomes byte range min.
var BYTE_MIN = 0;
var outOfRangeLo = ee.Number(BYTE_MIN - 12345);
print('Less than byte min:', outOfRangeLo);
var outOfRangeLoToByte = outOfRangeLo.byte();
print('Less than byte min cast to byte becomes byte min:', outOfRangeLoToByte);
Python 設定
請參閱
Python 環境頁面,瞭解 Python API 和如何使用 geemap
進行互動式開發。
import ee
import geemap.core as geemap
Colab (Python)
# Cast a number to unsigned 8-bit integer: [0, 255].
number = ee.Number(100)
print('Number:', number.getInfo())
byte_number = number.byte()
print('Number cast to byte:', byte_number.getInfo())
"""Casting numbers to byte that are outside of its range and precision can
modify the resulting value, note the behavior of the following scenarios.
"""
# A floating point number cast to byte loses decimal precision.
float_number = ee.Number(1.7)
print('Floating point value:', float_number.getInfo())
float_to_byte = float_number.byte()
print('Floating point value cast to byte:', float_to_byte.getInfo())
# A number greater than byte range max cast to byte becomes byte range max.
BYTE_MAX = 255
out_of_range_hi = ee.Number(BYTE_MAX + 12345)
print('Greater than byte max:', out_of_range_hi.getInfo())
out_of_range_hi_to_byte = out_of_range_hi.byte()
print('Greater than byte max cast to byte becomes byte max:',
out_of_range_hi_to_byte.getInfo())
# A number greater than byte range min cast to byte becomes byte range min.
BYTE_MIN = 0
out_of_range_lo = ee.Number(BYTE_MIN - 12345)
print('Less than byte min:', out_of_range_lo.getInfo())
out_of_range_lo_to_byte = out_of_range_lo.byte()
print('Less than byte min cast to byte becomes byte min:',
out_of_range_lo_to_byte.getInfo())
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上次更新時間:2025-07-26 (世界標準時間)。
[null,null,["上次更新時間:2025-07-26 (世界標準時間)。"],[[["\u003cp\u003e\u003ccode\u003enumber.byte()\u003c/code\u003e casts the input number to an unsigned 8-bit integer, resulting in a value within the range of 0 to 255.\u003c/p\u003e\n"],["\u003cp\u003eNumbers exceeding the maximum value of 255 will be truncated to 255, while numbers below 0 will be set to 0.\u003c/p\u003e\n"],["\u003cp\u003eWhen casting floating-point numbers, the decimal portion is lost, resulting in the nearest integer within the byte range.\u003c/p\u003e\n"]]],["The `byte()` method casts a number to an unsigned 8-bit integer, ranging from 0 to 255. Floating-point numbers lose decimal precision when cast. Numbers exceeding the byte range maximum (255) are capped at 255, and those below the minimum (0) become 0. The input value is cast to this range, modifying its value if outside of 0-255.\n"],null,["# ee.Number.byte\n\nCasts the input value to an unsigned 8-bit integer.\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|-----------------|---------|\n| Number.byte`()` | Number |\n\n| Argument | Type | Details |\n|---------------|--------|------------------|\n| this: `input` | Number | The input value. |\n\nExamples\n--------\n\n### Code Editor (JavaScript)\n\n```javascript\n// Cast a number to unsigned 8-bit integer: [0, 255].\nvar number = ee.Number(100);\nprint('Number:', number);\n\nvar byteNumber = number.byte();\nprint('Number cast to byte:', byteNumber);\n\n\n/**\n * Casting numbers to byte that are outside of its range and precision can\n * modify the resulting value, note the behavior of the following scenarios.\n */\n\n// A floating point number cast to byte loses decimal precision.\nvar float = ee.Number(1.7);\nprint('Floating point value:', float);\n\nvar floatToByte = float.byte();\nprint('Floating point value cast to byte:', floatToByte);\n\n// A number greater than byte range max cast to byte becomes byte range max.\nvar BYTE_MAX = 255;\nvar outOfRangeHi = ee.Number(BYTE_MAX + 12345);\nprint('Greater than byte max:', outOfRangeHi);\n\nvar outOfRangeHiToByte = outOfRangeHi.byte();\nprint('Greater than byte max cast to byte becomes byte max:', outOfRangeHiToByte);\n\n// A number greater than byte range min cast to byte becomes byte range min.\nvar BYTE_MIN = 0;\nvar outOfRangeLo = ee.Number(BYTE_MIN - 12345);\nprint('Less than byte min:', outOfRangeLo);\n\nvar outOfRangeLoToByte = outOfRangeLo.byte();\nprint('Less than byte min cast to byte becomes byte min:', outOfRangeLoToByte);\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# Cast a number to unsigned 8-bit integer: [0, 255].\nnumber = ee.Number(100)\nprint('Number:', number.getInfo())\n\nbyte_number = number.byte()\nprint('Number cast to byte:', byte_number.getInfo())\n\n\n\"\"\"Casting numbers to byte that are outside of its range and precision can\nmodify the resulting value, note the behavior of the following scenarios.\n\"\"\"\n\n# A floating point number cast to byte loses decimal precision.\nfloat_number = ee.Number(1.7)\nprint('Floating point value:', float_number.getInfo())\n\nfloat_to_byte = float_number.byte()\nprint('Floating point value cast to byte:', float_to_byte.getInfo())\n\n# A number greater than byte range max cast to byte becomes byte range max.\nBYTE_MAX = 255\nout_of_range_hi = ee.Number(BYTE_MAX + 12345)\nprint('Greater than byte max:', out_of_range_hi.getInfo())\n\nout_of_range_hi_to_byte = out_of_range_hi.byte()\nprint('Greater than byte max cast to byte becomes byte max:',\n out_of_range_hi_to_byte.getInfo())\n\n# A number greater than byte range min cast to byte becomes byte range min.\nBYTE_MIN = 0\nout_of_range_lo = ee.Number(BYTE_MIN - 12345)\nprint('Less than byte min:', out_of_range_lo.getInfo())\n\nout_of_range_lo_to_byte = out_of_range_lo.byte()\nprint('Less than byte min cast to byte becomes byte min:',\n out_of_range_lo_to_byte.getInfo())\n```"]]