Files
openlayers/src/ol/source/GeoTIFF.js

654 lines
20 KiB
JavaScript

/**
* @module ol/source/GeoTIFF
*/
import DataTile from './DataTile.js';
import State from './State.js';
import TileGrid from '../tilegrid/TileGrid.js';
import {Pool, fromUrl as tiffFromUrl, fromUrls as tiffFromUrls} from 'geotiff';
import {Projection, get as getCachedProjection} from '../proj.js';
import {clamp} from '../math.js';
import {create as createDecoderWorker} from '../worker/geotiff-decoder.js';
import {getIntersection} from '../extent.js';
import {toSize} from '../size.js';
import {fromCode as unitsFromCode} from '../proj/Units.js';
/**
* @typedef {Object} SourceInfo
* @property {string} url URL for the source GeoTIFF.
* @property {Array<string>} [overviews] List of any overview URLs.
* @property {number} [min=0] The minimum source data value. Rendered values are scaled from 0 to 1 based on
* the configured min and max.
* @property {number} [max] The maximum source data value. Rendered values are scaled from 0 to 1 based on
* the configured min and max.
* @property {number} [nodata] Values to discard. When provided, an additional band (alpha) will be added
* to the data.
* @property {Array<number>} [bands] Band numbers to be read from (where the first band is `1`). If not provided, all bands will
* be read. For example, if a GeoTIFF has blue (1), green (2), red (3), and near-infrared (4) bands, and you only need the
* near-infrared band, configure `bands: [4]`.
*/
/**
* @typedef {Object} GeoKeys
* @property {number} GTModelTypeGeoKey Model type.
* @property {number} GTRasterTypeGeoKey Raster type.
* @property {number} GeogAngularUnitsGeoKey Angular units.
* @property {number} GeogInvFlatteningGeoKey Inverse flattening.
* @property {number} GeogSemiMajorAxisGeoKey Semi-major axis.
* @property {number} GeographicTypeGeoKey Geographic coordinate system code.
* @property {number} ProjLinearUnitsGeoKey Projected linear unit code.
* @property {number} ProjectedCSTypeGeoKey Projected coordinate system code.
*/
/**
* @typedef {Object} GeoTIFFImage
* @property {Object} fileDirectory The file directory.
* @property {GeoKeys} geoKeys The parsed geo-keys.
* @property {boolean} littleEndian Uses little endian byte order.
* @property {Object} tiles The tile cache.
* @property {boolean} isTiled The image is tiled.
* @property {function():Array<number>} getBoundingBox Get the image bounding box.
* @property {function():Array<number>} getOrigin Get the image origin.
* @property {function(GeoTIFFImage):Array<number>} getResolution Get the image resolution.
*/
let workerPool;
function getWorkerPool() {
if (!workerPool) {
workerPool = new Pool(undefined, createDecoderWorker());
}
return workerPool;
}
/**
* Get the bounding box of an image. If the image does not have an affine transform,
* the pixel bounds are returned.
* @param {GeoTIFFImage} image The image.
* @return {Array<number>} The image bounding box.
*/
function getBoundingBox(image) {
try {
return image.getBoundingBox();
} catch (_) {
const fileDirectory = image.fileDirectory;
return [0, 0, fileDirectory.ImageWidth, fileDirectory.ImageLength];
}
}
/**
* Get the origin of an image. If the image does not have an affine transform,
* the top-left corner of the pixel bounds is returned.
* @param {GeoTIFFImage} image The image.
* @return {Array<number>} The image origin.
*/
function getOrigin(image) {
try {
return image.getOrigin().slice(0, 2);
} catch (_) {
return [0, image.fileDirectory.ImageLength];
}
}
/**
* Get the resolution of an image. If the image does not have an affine transform,
* the width of the image is compared with the reference image.
* @param {GeoTIFFImage} image The image.
* @param {GeoTIFFImage} referenceImage The reference image.
* @return {number} The image resolution.
*/
function getResolution(image, referenceImage) {
try {
return image.getResolution(referenceImage)[0];
} catch (_) {
return (
referenceImage.fileDirectory.ImageWidth / image.fileDirectory.ImageWidth
);
}
}
/**
* @param {GeoTIFFImage} image A GeoTIFF.
* @return {import("../proj/Projection.js").default} The image projection.
*/
function getProjection(image) {
const geoKeys = image.geoKeys;
if (!geoKeys) {
return null;
}
if (geoKeys.ProjectedCSTypeGeoKey) {
const code = 'EPSG:' + geoKeys.ProjectedCSTypeGeoKey;
let projection = getCachedProjection(code);
if (!projection) {
const units = unitsFromCode(geoKeys.ProjLinearUnitsGeoKey);
if (units) {
projection = new Projection({
code: code,
units: units,
});
}
}
return projection;
}
if (geoKeys.GeographicTypeGeoKey) {
const code = 'EPSG:' + geoKeys.GeographicTypeGeoKey;
let projection = getCachedProjection(code);
if (!projection) {
const units = unitsFromCode(geoKeys.GeogAngularUnitsGeoKey);
if (units) {
projection = new Projection({
code: code,
units: units,
});
}
}
return projection;
}
return null;
}
/**
* @param {import("geotiff/src/geotiff.js").GeoTIFF|import("geotiff/src/geotiff.js").MultiGeoTIFF} tiff A GeoTIFF.
* @return {Promise<Array<import("geotiff/src/geotiffimage.js").GeoTIFFImage>>} Resolves to a list of images.
*/
function getImagesForTIFF(tiff) {
return tiff.getImageCount().then(function (count) {
const requests = new Array(count);
for (let i = 0; i < count; ++i) {
requests[i] = tiff.getImage(i);
}
return Promise.all(requests);
});
}
/**
* @param {SourceInfo} source The GeoTIFF source.
* @return {Promise<Array<import("geotiff/src/geotiffimage.js").GeoTIFFImage>>} Resolves to a list of images.
*/
function getImagesForSource(source) {
let request;
if (source.overviews) {
request = tiffFromUrls(source.url, source.overviews);
} else {
request = tiffFromUrl(source.url);
}
return request.then(getImagesForTIFF);
}
/**
* @param {number|Array<number>|Array<Array<number>>} expected Expected value.
* @param {number|Array<number>|Array<Array<number>>} got Actual value.
* @param {number} tolerance Accepted tolerance in fraction of expected between expected and got.
* @param {string} message The error message.
*/
function assertEqual(expected, got, tolerance, message) {
if (Array.isArray(expected)) {
const length = expected.length;
if (!Array.isArray(got) || length != got.length) {
throw new Error(message);
}
for (let i = 0; i < length; ++i) {
assertEqual(expected[i], got[i], tolerance, message);
}
return;
}
got = /** @type {number} */ (got);
if (Math.abs(expected - got) > tolerance * expected) {
throw new Error(message);
}
}
/**
* @param {Array} array The data array.
* @return {number} The minimum value.
*/
function getMinForDataType(array) {
if (array instanceof Int8Array) {
return -128;
}
if (array instanceof Int16Array) {
return -32768;
}
if (array instanceof Int32Array) {
return -2147483648;
}
if (array instanceof Float32Array) {
return 1.2e-38;
}
return 0;
}
/**
* @param {Array} array The data array.
* @return {number} The maximum value.
*/
function getMaxForDataType(array) {
if (array instanceof Int8Array) {
return 127;
}
if (array instanceof Uint8Array) {
return 255;
}
if (array instanceof Uint8ClampedArray) {
return 255;
}
if (array instanceof Int16Array) {
return 32767;
}
if (array instanceof Uint16Array) {
return 65535;
}
if (array instanceof Int32Array) {
return 2147483647;
}
if (array instanceof Uint32Array) {
return 4294967295;
}
if (array instanceof Float32Array) {
return 3.4e38;
}
return 255;
}
/**
* @typedef {Object} Options
* @property {Array<SourceInfo>} sources List of information about GeoTIFF sources.
* Multiple sources can be combined when their resolution sets are equal after applying a scale.
* The list of sources defines a mapping between input bands as they are read from each GeoTIFF and
* the output bands that are provided by data tiles. To control which bands to read from each GeoTIFF,
* use the {@link import("./GeoTIFF.js").SourceInfo bands} property. If, for example, you specify two
* sources, one with 3 bands and {@link import("./GeoTIFF.js").SourceInfo nodata} configured, and
* another with 1 band, the resulting data tiles will have 5 bands: 3 from the first source, 1 alpha
* band from the first source, and 1 band from the second source.
* @property {boolean} [convertToRGB = false] By default, bands from the sources are read as-is. When
* reading GeoTIFFs with the purpose of displaying them as RGB images, setting this to `true` will
* convert other color spaces (YCbCr, CMYK) to RGB.
* @property {boolean} [opaque=false] Whether the layer is opaque.
* @property {number} [transition=250] Duration of the opacity transition for rendering.
* To disable the opacity transition, pass `transition: 0`.
*/
/**
* @classdesc
* A source for working with GeoTIFF data.
* @api
*/
class GeoTIFFSource extends DataTile {
/**
* @param {Options} options Data tile options.
*/
constructor(options) {
super({
state: State.LOADING,
tileGrid: null,
projection: null,
opaque: options.opaque,
transition: options.transition,
});
/**
* @type {Array<SourceInfo>}
* @private
*/
this.sourceInfo_ = options.sources;
const numSources = this.sourceInfo_.length;
/**
* @type {Array<Array<import("geotiff/src/geotiffimage.js").GeoTIFFImage>>}
* @private
*/
this.sourceImagery_ = new Array(numSources);
/**
* @type {Array<number>}
* @private
*/
this.resolutionFactors_ = new Array(numSources);
/**
* @type {Array<number>}
* @private
*/
this.samplesPerPixel_;
/**
* @type {Array<Array<number>>}
* @private
*/
this.nodataValues_;
/**
* @type {boolean}
* @private
*/
this.addAlpha_ = false;
/**
* @type {Error}
* @private
*/
this.error_ = null;
/**
* @type {'readRasters' | 'readRGB'}
*/
this.readMethod_ = options.convertToRGB ? 'readRGB' : 'readRasters';
this.setKey(this.sourceInfo_.map((source) => source.url).join(','));
const self = this;
const requests = new Array(numSources);
for (let i = 0; i < numSources; ++i) {
requests[i] = getImagesForSource(this.sourceInfo_[i]);
}
Promise.all(requests)
.then(function (sources) {
self.configure_(sources);
})
.catch(function (error) {
console.error(error); // eslint-disable-line no-console
self.error_ = error;
self.setState(State.ERROR);
});
}
/**
* @return {Error} A source loading error. When the source state is `error`, use this function
* to get more information about the error. To debug a faulty configuration, you may want to use
* a listener like
* ```js
* geotiffSource.on('change', () => {
* if (geotiffSource.getState() === 'error') {
* console.error(geotiffSource.getError());
* }
* });
* ```
*/
getError() {
return this.error_;
}
/**
* Configure the tile grid based on images within the source GeoTIFFs. Each GeoTIFF
* must have the same internal tiled structure.
* @param {Array<Array<import("geotiff/src/geotiffimage.js").GeoTIFFImage>>} sources Each source is a list of images
* from a single GeoTIFF.
* @private
*/
configure_(sources) {
let extent;
let origin;
let tileSizes;
let resolutions;
const samplesPerPixel = new Array(sources.length);
const nodataValues = new Array(sources.length);
let minZoom = 0;
const sourceCount = sources.length;
for (let sourceIndex = 0; sourceIndex < sourceCount; ++sourceIndex) {
const images = sources[sourceIndex];
const imageCount = images.length;
let sourceExtent;
let sourceOrigin;
const sourceTileSizes = new Array(imageCount);
const sourceResolutions = new Array(imageCount);
nodataValues[sourceIndex] = new Array(imageCount);
for (let imageIndex = 0; imageIndex < imageCount; ++imageIndex) {
const image = images[imageIndex];
const nodataValue = image.getGDALNoData();
nodataValues[sourceIndex][imageIndex] =
nodataValue === null ? NaN : nodataValue;
const wantedSamples = this.sourceInfo_[sourceIndex].bands;
samplesPerPixel[sourceIndex] = wantedSamples
? wantedSamples.length
: image.getSamplesPerPixel();
const level = imageCount - (imageIndex + 1);
if (!sourceExtent) {
sourceExtent = getBoundingBox(image);
}
if (!sourceOrigin) {
sourceOrigin = getOrigin(image);
}
sourceResolutions[level] = getResolution(image, images[0]);
sourceTileSizes[level] = [image.getTileWidth(), image.getTileHeight()];
}
if (!extent) {
extent = sourceExtent;
} else {
getIntersection(extent, sourceExtent, extent);
}
if (!origin) {
origin = sourceOrigin;
} else {
const message = `Origin mismatch for source ${sourceIndex}, got [${sourceOrigin}] but expected [${origin}]`;
assertEqual(origin, sourceOrigin, 0, message);
}
if (!resolutions) {
resolutions = sourceResolutions;
this.resolutionFactors_[sourceIndex] = 1;
} else {
if (resolutions.length - minZoom > sourceResolutions.length) {
minZoom = resolutions.length - sourceResolutions.length;
}
const resolutionFactor =
resolutions[resolutions.length - 1] /
sourceResolutions[sourceResolutions.length - 1];
this.resolutionFactors_[sourceIndex] = resolutionFactor;
const scaledSourceResolutions = sourceResolutions.map(
(resolution) => (resolution *= resolutionFactor)
);
const message = `Resolution mismatch for source ${sourceIndex}, got [${scaledSourceResolutions}] but expected [${resolutions}]`;
assertEqual(
resolutions.slice(minZoom, resolutions.length),
scaledSourceResolutions,
0.005,
message
);
}
if (!tileSizes) {
tileSizes = sourceTileSizes;
} else {
assertEqual(
tileSizes.slice(minZoom, tileSizes.length),
sourceTileSizes,
0,
`Tile size mismatch for source ${sourceIndex}`
);
}
this.sourceImagery_[sourceIndex] = images.reverse();
}
for (let i = 0, ii = this.sourceImagery_.length; i < ii; ++i) {
const sourceImagery = this.sourceImagery_[i];
while (sourceImagery.length < resolutions.length) {
sourceImagery.unshift(undefined);
}
}
if (!this.getProjection()) {
const firstSource = sources[0];
for (let i = firstSource.length - 1; i >= 0; --i) {
const image = firstSource[i];
const projection = getProjection(image);
if (projection) {
this.projection = projection;
break;
}
}
}
this.samplesPerPixel_ = samplesPerPixel;
this.nodataValues_ = nodataValues;
// decide if we need to add an alpha band to handle nodata
outer: for (let sourceIndex = 0; sourceIndex < sourceCount; ++sourceIndex) {
// option 1: source is configured with a nodata value
if (this.sourceInfo_[sourceIndex].nodata !== undefined) {
this.addAlpha_ = true;
break;
}
const values = nodataValues[sourceIndex];
// option 2: check image metadata for limited bands
const bands = this.sourceInfo_[sourceIndex].bands;
if (bands) {
for (let i = 0; i < bands.length; ++i) {
if (!isNaN(values[bands[i] - 1])) {
this.addAlpha_ = true;
break outer;
}
}
continue;
}
// option 3: check image metadata for all bands
for (let imageIndex = 0; imageIndex < values.length; ++imageIndex) {
if (!isNaN(values[imageIndex])) {
this.addAlpha_ = true;
break outer;
}
}
}
const additionalBands = this.addAlpha_ ? 1 : 0;
this.bandCount =
samplesPerPixel.reduce((accumulator, value) => {
accumulator += value;
return accumulator;
}, 0) + additionalBands;
const tileGrid = new TileGrid({
extent: extent,
minZoom: minZoom,
origin: origin,
resolutions: resolutions,
tileSizes: tileSizes,
});
this.tileGrid = tileGrid;
this.setLoader(this.loadTile_.bind(this));
this.setState(State.READY);
}
loadTile_(z, x, y) {
const size = toSize(this.tileGrid.getTileSize(z));
const sourceCount = this.sourceImagery_.length;
const requests = new Array(sourceCount);
const addAlpha = this.addAlpha_;
const bandCount = this.bandCount;
const samplesPerPixel = this.samplesPerPixel_;
const sourceInfo = this.sourceInfo_;
for (let sourceIndex = 0; sourceIndex < sourceCount; ++sourceIndex) {
const source = sourceInfo[sourceIndex];
const resolutionFactor = this.resolutionFactors_[sourceIndex];
const pixelBounds = [
Math.round(x * (size[0] * resolutionFactor)),
Math.round(y * (size[1] * resolutionFactor)),
Math.round((x + 1) * (size[0] * resolutionFactor)),
Math.round((y + 1) * (size[1] * resolutionFactor)),
];
const image = this.sourceImagery_[sourceIndex][z];
let samples;
if (source.bands) {
samples = source.bands.map(function (bandNumber) {
return bandNumber - 1;
});
}
requests[sourceIndex] = image[this.readMethod_]({
window: pixelBounds,
width: size[0],
height: size[1],
samples: samples,
fillValue: source.nodata,
pool: getWorkerPool(),
interleave: false,
});
}
const pixelCount = size[0] * size[1];
const dataLength = pixelCount * bandCount;
const nodataValues = this.nodataValues_;
return Promise.all(requests).then(function (sourceSamples) {
const data = new Uint8Array(dataLength);
let dataIndex = 0;
for (let pixelIndex = 0; pixelIndex < pixelCount; ++pixelIndex) {
let transparent = addAlpha;
for (let sourceIndex = 0; sourceIndex < sourceCount; ++sourceIndex) {
const source = sourceInfo[sourceIndex];
let min = source.min;
if (min === undefined) {
min = getMinForDataType(sourceSamples[sourceIndex][0]);
}
let max = source.max;
if (max === undefined) {
max = getMaxForDataType(sourceSamples[sourceIndex][0]);
}
const gain = 255 / (max - min);
const bias = -min * gain;
for (
let sampleIndex = 0;
sampleIndex < samplesPerPixel[sourceIndex];
++sampleIndex
) {
const sourceValue =
sourceSamples[sourceIndex][sampleIndex][pixelIndex];
const value = clamp(gain * sourceValue + bias, 0, 255);
if (!addAlpha) {
data[dataIndex] = value;
} else {
let nodata = source.nodata;
if (nodata === undefined) {
let bandIndex;
if (source.bands) {
bandIndex = source.bands[sampleIndex] - 1;
} else {
bandIndex = sampleIndex;
}
nodata = nodataValues[sourceIndex][bandIndex];
}
if (sourceValue !== nodata) {
transparent = false;
data[dataIndex] = value;
}
}
dataIndex++;
}
}
if (addAlpha) {
if (!transparent) {
data[dataIndex] = 255;
}
dataIndex++;
}
}
return data;
});
}
}
export default GeoTIFFSource;