最近项目中有需要直接加载三方给的后缀名tif格式的文件
<script src="https://cdn.jsdelivr.net/npm/geotiff"></script>
或者
yarn add geotiff
npm install geotiff
新建tifs.js
import GeoTIFF, { fromBlob, fromUrl, fromArrayBuffer } from 'geotiff';
import GeoTIFFImage from 'geotiff/dist-node/geotiffimage';
var tiff;
var image;
var rectangle;
class GeoTiffUtil {
constructor() {
}
async init(){
this.tiff = await fromUrl('http://xxxx.tif');
this.image = await this.tiff.getImage();
let [west, south, east, north] = this.image.getBoundingBox();
const code =
this.image.geoKeys.ProjectedCSTypeGeoKey ||
this.image.geoKeys.GeographicTypeGeoKey;
let { x: w, y: n } = await (
await fetch(
`//epsgIo/trans?x=${west}&y=${north}&s_srs=${code}&t_srs=4326`
)
).json();
let { x: e, y: s } = await (
await fetch(
`//epsgIo/trans?x=${east}&y=${south}&s_srs=${code}&t_srs=4326`
)
).json();
const [red = [], green = [], blue = []] = await this.image.readRasters();
// 将像素信息写入canvas
const canvas = document.createElement("canvas");
let width = this.image.getWidth();
let height = this.image.getHeight();
canvas.width = width;
canvas.height = height;
let ctx = canvas.getContext("2d");
let imageData = ctx.createImageData(width, height);
for (var i = 0; i < imageData.data.length / 4; i += 1) {
imageData.data[i * 4 + 0] = red[i];
imageData.data[i * 4 + 1] = green[i] || 0;
imageData.data[i * 4 + 2] = blue[i] || 0;
imageData.data[i * 4 + 3] = red[i] === 0 ? 0 : 255;
}
ctx.putImageData(imageData, 0, 0);
return {canvas:canvas,rectangle:[w, s, e, n]};
}
}
export default new GeoTiffUtil();
index.vue
import GeoTiffUtil from '@/utils/tifs.js';
GeoTiffUtil.init().then((res)=>{
let rectangle = Cesium.Rectangle.fromDegrees(res.rectangle[0], res.rectangle[1],
res.rectangle[2],res.rectangle[3]);
let du = res.canvas.toDataURL();
viewer.imageryLayers.addImageryProvider(
new Cesium.SingleTileImageryProvider({
url: du,
rectangle,
})
);
viewer.camera.setView({
destination: rectangle,
});
})