antv-l7/packages/site/examples/raster/single_raster/demo/dem_quantize.js

50 lines
1.5 KiB
JavaScript

// https://gw.alipayobjects.com/zos/antvdemo/assets/2019_clip/ndvi_201905.tif
import { RasterLayer, Scene } from '@antv/l7';
import { GaodeMap } from '@antv/l7-maps';
import * as GeoTIFF from 'geotiff';
const scene = new Scene({
id: 'map',
map: new GaodeMap({
center: [121.268, 30.3628],
zoom: 3,
}),
});
async function getTiffData() {
const response = await fetch(
'https://gw.alipayobjects.com/os/rmsportal/XKgkjjGaAzRyKupCBiYW.dat',
);
const arrayBuffer = await response.arrayBuffer();
return arrayBuffer;
}
scene.on('loaded', async () => {
const tiffdata = await getTiffData();
const tiff = await GeoTIFF.fromArrayBuffer(tiffdata);
const image = await tiff.getImage();
const width = image.getWidth();
const height = image.getHeight();
const values = await image.readRasters();
const layer = new RasterLayer();
layer
.source(values[0], {
parser: {
type: 'raster',
width,
height,
extent: [73.482190241, 3.82501784112, 135.106618732, 57.6300459963],
},
})
.style({
opacity: 1,
clampLow: false,
clampHigh: false,
domain: [0, 10000],
rampColors: {
type:'quantize', // 等间距 不需要设置 position
colors: ['#b2182b','#d6604d','#f4a582','#fddbc7','#f7f7f7','#d1e5f0','#92c5de','#4393c3','#2166ac'],
},
});
scene.addLayer(layer)
});