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我正在尝试使用 OpenLayers 5 在我的地图上添加卫星图像。

问题是我无法做到这一点，因为我刚刚找到了一个选项，可以在地图上添加图像，传递图像范围（xmin、ymin、xmax、ymax）而不是边界框。图像应适合边界框。由于这个原因，图像被扭曲了。

图像为 JPG 文件（属性 feature.properties.icon）。示例：http ://exampleserver.com/220/063/353LGN00/353LGN00_thumb_large.jpg

我想要的结果是这样的：

在此处输入图像描述

我得到的结果是：

在此处输入图像描述

我在地图上添加此图像的代码如下：

import ImageLayer from 'ol/layer/Image'
import Static from 'ol/source/ImageStatic'

...

this.olmap = new Map({
    target: 'map',
    layers: [
      baseLayerGroup, rasterLayerGroup, vectorLayer
    ],
    view: new View({
        projection: 'EPSG:4326',
        center: [ -45.8392, -3.65286 ],
        zoom: 8
    })
})

...

this.rasterLayerGroup.getLayers().push(
    new ImageLayer({
        source: new Static({
            url: feature.properties.icon,
            projection: 'EPSG:4326',
            imageExtent: [
              feature.properties.bl_longitude, feature.properties.bl_latitude,
              feature.properties.tr_longitude, feature.properties.tr_latitude
            ]  
        })
    })
)

有人知道如何传递图像边界框而不仅仅是图像范围吗？

先感谢您。

编辑 1：迈克的解决方案

通过 Mike 的解决方案，我能够修复一些图像存在的错误（靠近赤道线）。出于这个原因，他的回答解决了我的问题，并将图像插入到我在创建问题时所期望的更好位置。

然而，这个解决方案对我来说适用于赤道线附近的图像。两极旁边的图像保持扭曲（编辑 2）。

我在下面发送了一张说明最终结果的图片：

在此处输入图像描述

编辑2：新问题？

我正在测试一些图像，我发现了一个新错误。现在我发现图像应该适合边界框。如果图像不适合 bbox，它会保持失真，例如我在下面发送的打印说明。

在此处输入图像描述

该图像应适合 bbox 内，如下图[PS 1]所示：

在此处输入图像描述

我相信这可能是重投影的问题，但我不知道，因为视图投影和图像投影都是EPSG：4326。

我试图按照 Openlayers 网站上关于 Raster Reprojection[1.] 的解释进行操作，但是我无法重现它，因为正如我所说，两个投影（视图和图像）是相同的（或者它们应该是相同的）。

我在包含与上图相关信息的 GeoJSON 下方发送。该图像可以在“properties.icon”（http://www.dpi.inpe.br/newcatalog/tmp/MOD13Q1/2018/MOD13Q1.A2018017.h13v14.jpg）中找到。bbox 坐标可以在“geometry.coordinates”或“properties.bl_latitude”、“properties.bl_longitude”、“properties.br_latitude”等中找到。“bl”表示“左下”，“br”表示“右下”，“tl”表示“左上”，“tr”表示“右上”。“properties”中的这些坐标在“geometry.coordinates”中是相同的。

{
  "geometry": {
    "coordinates": [
      [
        [
          -77.7862,
          -50
        ],
        [
          -100,
          -60
        ],
        [
          -80,
          -60
        ],
        [
          -62.229,
          -50
        ],
        [
          -77.7862,
          -50
        ]
      ]
    ],
    "type": "Polygon"
  },
  "properties": {
    "alternate": "http://www.dpi.inpe.br/opensearch/v2/granule.json?uid=MOD13Q1.A2018017.h13v14",
    "auxpath": null,
    "bitslips": null,
    "bl_latitude": -60,
    "bl_longitude": -100,
    "br_latitude": -60,
    "br_longitude": -80,
    "centerlatitude": -55,
    "centerlongitude": -80.0038,
    "centertime": null,
    "cloud": 0,
    "cloudcovermethod": "M",
    "dataset": "MOD13Q1",
    "date": "2018-01-17T00:00:00",
    "enclosure": [
      {
        "band": "evi",
        "radiometric_processing": "SR",
        "type": "MOSAIC",
        "url": "http://www.dpi.inpe.br/newcatalog/tmp/MOD13Q1/2018/MOD13Q1.A2018017.h13v14.006.2018033223827.hdf"
      },
      {
        "band": "ndvi",
        "radiometric_processing": "SR",
        "type": "MOSAIC",
        "url": "http://www.dpi.inpe.br/newcatalog/tmp/MOD13Q1/2018/MOD13Q1.A2018017.h13v14.006.2018033223827.hdf"
      },
      ...
    ],
    "icon": "http://www.dpi.inpe.br/newcatalog/tmp/MOD13Q1/2018/MOD13Q1.A2018017.h13v14.jpg",
    "id": "http://www.dpi.inpe.br/opensearch/v2/granule.json?uid=MOD13Q1.A2018017.h13v14",
    "orbit": 0,
    "path": 14,
    "provider": "OP_CBERS1",
    "row": 13,
    "satellite": "T1",
    "sensor": "MODIS",
    "title": "MOD13Q1.A2018017.h13v14",
    "tl_latitude": -50,
    "tl_longitude": -77.7862,
    "tr_latitude": -50,
    "tr_longitude": -62.229,
    "type": "IMAGES",
    "updated": "2018-03-01T18:51:56",
    "via": "http://www.dpi.inpe.br/opensearch/v2/metadata/MOD13Q1.A2018017.h13v14"
  },
  "type": "Feature"
}

有人会有新想法吗？

[PS 1]：使图像适合 bbox 的原始代码是传单代码 [2.]，我将其发送到下面：

var map = L.map('map').setView([-15.22, -53.23], 5)

...

var anchor = [
    [feature.properties.tl_latitude, feature.properties.tl_longitude],
    [feature.properties.tr_latitude, feature.properties.tr_longitude],
    [feature.properties.br_latitude, feature.properties.br_longitude],
    [feature.properties.bl_latitude, feature.properties.bl_longitude]
]

layer._quicklook = L.imageTransform(feature.properties.icon, anchor).addTo(map)

[1.] https://openlayers.org/en/latest/doc/tutorials/raster-reprojection.html

[2.] https://github.com/ScanEx/Leaflet.imageTransform

4

1 回答 1

1

如果坐标是照片的坐标并且包含旋转照片的 jpg 在 EPSG:4326 中（即与经线和平行线对齐），那么您需要一个包含照片所有角的边界框

import {boundingExtent} from 'ol/extent';

....

this.rasterLayerGroup.getLayers().push(
    new ImageLayer({
        source: new Static({
            url: feature.properties.icon,
            projection: 'EPSG:4326',
            imageExtent: boundingExtent([
              [feature.properties.bl_longitude, feature.properties.bl_latitude],
              [feature.properties.br_longitude, feature.properties.br_latitude],
              [feature.properties.tl_longitude, feature.properties.tl_latitude],
              [feature.properties.tr_longitude, feature.properties.tr_latitude]
            ])  
        })
    })
)

但是，您的顶部屏幕截图使 jpg 本身旋转。如果需要，投影不是 EPSG:4326，您需要定义一个自定义投影来处理旋转。

我已经设法接近了一些东西，但是简单地拉伸图像以适应多边形并不能在传单方法的一侧给出精确的对齐

var properties = {
    "bl_latitude": -60,
    "bl_longitude": -100,
    "br_latitude": -60,
    "br_longitude": -80,
    "centerlatitude": -55,
    "centerlongitude": -80.0038,
    "icon": "https://www.mikenunn.net/demo/MOD13Q1.A2018017.h13v14.jpg",
    "tl_latitude": -50,
    "tl_longitude": -77.7862,
    "tr_latitude": -50,
    "tr_longitude": -62.229,
};

function overlaySource ( properties ) {

    var projection = ol.proj.get('EPSG:3857');  // leaflet projection

    var extentSize = [0, 0, 4096, 4096];  // arbitary extent for the projection transforms
    var size0 = extentSize[2];
    var size1 = extentSize[3];

    var url = properties.icon;

    var bl = ol.proj.transform([properties.bl_longitude, properties.bl_latitude], 'EPSG:4326', projection);
    var tl = ol.proj.transform([properties.tl_longitude, properties.tl_latitude], 'EPSG:4326', projection);
    var br = ol.proj.transform([properties.br_longitude, properties.br_latitude], 'EPSG:4326', projection);
    var tr = ol.proj.transform([properties.tr_longitude, properties.tr_latitude], 'EPSG:4326', projection);

    function normalTransform(coordinates, output, dimensions) {
        var dims = dimensions || 2;
        for (var i=0; i<coordinates.length; i+=dims) {

            var left = bl[0] + (tl[0]-bl[0]) * coordinates[i+1]/size1;
            var right = br[0] + (tr[0]-br[0]) * coordinates[i+1]/size1;

            var top = tl[1] + (tr[1]-tl[1]) * coordinates[i]/size0;
            var bottom = bl[1] + (br[1]-bl[1]) * coordinates[i]/size0;

            var newCoordinates0 = left + (right-left) * coordinates[i]/size0;
            var newCoordinates1 = bottom + (top-bottom) * coordinates[i+1]/size1;

            c = ol.proj.transform([newCoordinates0, newCoordinates1], projection, 'EPSG:3857');

            //console.log(coordinates[i] + ' ' + coordinates[i+1] + ' ' + c[0] + ' ' + c[1]);

            coordinates[i] = c[0];
            coordinates[i+1] = c[1];

        }
        return coordinates;
    }

    function rotateTransform(coordinates, output, dimensions) {
        var dims = dimensions || 2;
        for (var i=0; i<coordinates.length; i+=dims) {

            c = ol.proj.transform([coordinates[i], coordinates[i+1]], 'EPSG:3857', projection);

            var left = bl[0] + (tl[0]-bl[0]) * (c[1]-bl[1]) /(tl[1]-bl[1]);
            var right = br[0] + (tr[0]-br[0]) * (c[1]-br[1]) /(tr[1]-br[1]);

            var top = tl[1] + (tr[1]-tl[1]) * (c[0]-tl[0])/(tr[0]-tl[0]);
            var bottom = bl[1] + (br[1]-bl[1]) * (c[0]-bl[0])/(br[0]-bl[0]);

            var newCoordinates0 = (c[0]-left)*size0/(right-left);
            var newCoordinates1 = (c[1]-bottom)*size1/(top-bottom);

            //console.log(coordinates[i] + ' ' + coordinates[i+1] + ' ' + newCoordinates0 + ' ' + newCoordinates1);

            coordinates[i] = newCoordinates0;
            coordinates[i+1] = newCoordinates1;

        }
        return coordinates;
    }

    var rotatedProjection = new ol.proj.Projection({
        code: 'EPSG:' + url + 'rotated',
        units: 'm',
        extent: extentSize
    });
    ol.proj.addProjection(rotatedProjection);

    ol.proj.addCoordinateTransforms('EPSG:3857', rotatedProjection,
        function(coordinate) {
            return rotateTransform(coordinate);
        },
        function(coordinate) {
            return normalTransform(coordinate);
        }
    );

    ol.proj.addCoordinateTransforms('EPSG:4326', rotatedProjection,
        function(coordinate) {
            return rotateTransform(ol.proj.transform(coordinate, "EPSG:4326", "EPSG:3857"));
        },
        function(coordinate) {
            return ol.proj.transform(normalTransform(coordinate), "EPSG:3857", "EPSG:4326");
        }
    );

    return new ol.source.ImageStatic({
        projection: rotatedProjection,
        imageExtent: extentSize,
        url: url
    });

}

var tileLayer = new ol.layer.Tile({
    source: new ol.source.XYZ({
        attributions: [
            'Powered by Esri',
            'Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN, and the GIS User Community'
        ],
        //attributionsCollapsible: false,
        url: 'https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}',
        maxZoom: 23
    })
});

var imageLayer = new ol.layer.Image({
    source:  overlaySource( properties ),
    opacity: 0.7
})

var map = new ol.Map({
    layers: [tileLayer, imageLayer],
    target: 'map',
    logo: false,
    view: new ol.View()
});

var imageProj = imageLayer.getSource().getProjection();
map.getView().fit(ol.proj.transformExtent(imageProj.getExtent(), imageProj, map.getView().getProjection()), {constrainResolution: false});
html, body, .map {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
}
<link href="https://cdn.rawgit.com/openlayers/openlayers.github.io/master/en/v5.3.0/css/ol.css" rel="stylesheet" />
<script src="https://cdn.rawgit.com/openlayers/openlayers.github.io/master/en/v5.3.0/build/ol.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/proj4js/2.5.0/proj4.js"></script>
<div id="map" class="map"></div>

这是我的 KML 方法，但这是将矩形简单旋转指定角度，而不是将其扭曲成只有两条边平行的四边形。

function kmlOverlaySource ( kmlExtent, // KMLs specify the extent the unrotated image would occupy
                            url,
                            rotation,
                            imageSize,
) {

    // calculate latitude of true scale of equidistant cylindrical projection based on pixels per degree on each axis

    proj4.defs('EPSG:' + url, '+proj=eqc +lat_ts=' +
                              (Math.acos((ol.extent.getHeight(kmlExtent)/imageSize[1])
                                        /(ol.extent.getWidth(kmlExtent)/imageSize[0]))*180/Math.PI) +
                              ' +lat_0=0 +lon_0=0 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs');

    if (ol.proj.proj4 && ol.proj.proj4.register) { ol.proj.proj4.register(proj4); } // if OL5 register proj4

    // convert the extents to source projection coordinates

    var projection = ol.proj.get('EPSG:' + url);
    var projExtent = ol.proj.transformExtent(kmlExtent, 'EPSG:4326', projection);

    var angle = -rotation * Math.PI/180;

    function rotateTransform(coordinates, output, dimensions) {
        var dims = dimensions || 2;
        for (var i=0; i<coordinates.length; i+=dims) {
            var point = new ol.geom.Point([coordinates[i],coordinates[i+1]]);
            point.rotate(angle, ol.extent.getCenter(projExtent));
            var newCoordinates = point.getCoordinates();
            coordinates[i] = newCoordinates[0];
            coordinates[i+1] = newCoordinates[1];
        }
        return coordinates;
    }

    function normalTransform(coordinates, output, dimensions) {
        var dims = dimensions || 2;
        for (var i=0; i<coordinates.length; i+=dims) {
            var point = new ol.geom.Point([coordinates[i],coordinates[i+1]]);
            point.rotate(-angle, ol.extent.getCenter(projExtent));
            var newCoordinates = point.getCoordinates();
            coordinates[i] = newCoordinates[0];
            coordinates[i+1] = newCoordinates[1];
        }
        return coordinates;
    }

    var rotatedProjection = new ol.proj.Projection({
        code: 'EPSG:' + url + 'rotated',
        units: 'm',
        extent: projExtent
    });
    ol.proj.addProjection(rotatedProjection);

    ol.proj.addCoordinateTransforms('EPSG:4326', rotatedProjection,
        function(coordinate) {
            return rotateTransform(ol.proj.transform(coordinate, 'EPSG:4326', projection));
        },
        function(coordinate) {
            return ol.proj.transform(normalTransform(coordinate), projection, 'EPSG:4326');
        }
    );

    ol.proj.addCoordinateTransforms('EPSG:3857', rotatedProjection,
        function(coordinate) {
            return rotateTransform(ol.proj.transform(coordinate, 'EPSG:3857', projection));
        },
        function(coordinate) {
            return ol.proj.transform(normalTransform(coordinate), projection, 'EPSG:3857');
        }
    );

    return new ol.source.ImageStatic({
        projection: rotatedProjection,
        url: url,
        imageExtent: projExtent
    });

}

var tileLayer = new ol.layer.Tile({
    source: new ol.source.XYZ({
        attributions: [
            'Powered by Esri',
            'Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN, and the GIS User Community'
        ],
        //attributionsCollapsible: false,
        url: 'https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}',
        maxZoom: 23
    })
});

// these would normally be parsed from a KML file
var kmlExtent = [8.433995415151397, 46.65804355828784, 9.144871415151389, 46.77980155828784];
var url = 'https://raw.githubusercontent.com/ReneNyffenegger/about-GoogleEarth/master/kml/the_png_says.png'
var rotation = 30;
var imageSize = [];

var img = document.createElement('img');
img.onload = imageLoaded;
img.src = url;

function imageLoaded() {

    imageSize[0] = img.width;
    imageSize[1] = img.height;

    var imageLayer = new ol.layer.Image({
        source: kmlOverlaySource(kmlExtent, url, rotation, imageSize),
    });

    var map = new ol.Map({
        layers: [tileLayer, imageLayer],
        target: 'map',
        logo: false,
        view: new ol.View()
    });

    var imageProj = imageLayer.getSource().getProjection();
    map.getView().fit(ol.proj.transformExtent(imageProj.getExtent(), imageProj, map.getView().getProjection()), {constrainResolution: false});

}
html, body, .map {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
}
<link href="https://cdn.rawgit.com/openlayers/openlayers.github.io/master/en/v5.3.0/css/ol.css" rel="stylesheet" />
<script src="https://cdn.rawgit.com/openlayers/openlayers.github.io/master/en/v5.3.0/build/ol.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/proj4js/2.5.0/proj4.js"></script>
<div id="map" class="map"></div>

于 2019-03-27T12:34:02.350 回答