1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
| import DataTileSource from 'ol/source/DataTile.js';
import Map from 'ol/Map.js';
import TileLayer from 'ol/layer/WebGLTile.js';
import View from 'ol/View.js';
import {fromLonLat} from 'ol/proj.js';
const COG =
'https://storage.googleapis.com/open-cogs/stac-examples/20201211_223832_CS2_analytic.tif';
function numpyTileLoader(z, x, y) {
const url = `https://api.cogeo.xyz/cog/tiles/WebMercatorQuad/${z}/${x}/${y}@1x?format=npy&url=${encodeURIComponent(
COG
)}`;
return fetch(url)
.then((r) => r.arrayBuffer())
.then((buffer) => NumpyLoader.fromArrayBuffer(buffer))
.then((numpyData) => {
const dataTile = new Float32Array(256 * 256 * 5);
const bandSize = 256 * 256;
for (let x = 0; x < 256; x++) {
for (let y = 0; y < 256; y++) {
const px = x + y * 256;
dataTile[px * 5 + 0] = numpyData.data[y * 256 + x];
dataTile[px * 5 + 1] = numpyData.data[bandSize + y * 256 + x];
dataTile[px * 5 + 2] = numpyData.data[bandSize * 2 + y * 256 + x];
dataTile[px * 5 + 3] = numpyData.data[bandSize * 3 + y * 256 + x];
dataTile[px * 5 + 4] =
numpyData.data[bandSize * 4 + y * 256 + x] > 0 ? 1.0 : 0;
}
}
return dataTile;
});
}
const interpolateBand = (bandIdx) => [
'interpolate',
['linear'],
['band', bandIdx],
['var', 'bMin'],
0,
['var', 'bMax'],
1,
];
const initialMin = 3000;
const initialMax = 18000;
const numpyLayer = new TileLayer({
style: {
color: [
'array',
interpolateBand(3),
interpolateBand(2),
interpolateBand(1),
['band', 5],
],
variables: {
'bMin': initialMin,
'bMax': initialMax,
},
},
source: new DataTileSource({
loader: numpyTileLoader,
bandCount: 5,
}),
});
const map = new Map({
target: 'map',
layers: [numpyLayer],
view: new View({
center: fromLonLat([172.933, 1.3567]),
zoom: 15,
}),
});
const inputMin = document.getElementById('input-min');
const inputMax = document.getElementById('input-max');
const outputMin = document.getElementById('output-min');
const outputMax = document.getElementById('output-max');
inputMin.addEventListener('input', (evt) => {
numpyLayer.updateStyleVariables({
'bMin': parseFloat(evt.target.value),
'bMax': parseFloat(inputMax.value),
});
outputMin.innerText = evt.target.value;
});
inputMax.addEventListener('input', (evt) => {
numpyLayer.updateStyleVariables({
'bMin': parseFloat(inputMin.value),
'bMax': parseFloat(evt.target.value),
});
outputMax.innerText = evt.target.value;
});
inputMin.value = initialMin;
inputMax.value = initialMax;
outputMin.innerText = initialMin;
outputMax.innerText = initialMax;
|
)
