module.exports = function(RED) { "use strict"; var ExifImage = require('exif').ExifImage; function convertDegreesMinutesSecondsToDecimals(degrees, minutes, seconds) { var result; result = degrees + (minutes / 60) + (seconds / 3600); return result; } function ExifNode(n) { RED.nodes.createNode(this,n); this.mode = n.mode || "normal"; if (this.mode === "worldmap") { this.property = "payload.content"; } else { this.property = n.property || "payload"; } var node = this; /*** * Extracts GPS location information from Exif data. If enough information is * provided, convert the Exif data into a pair of single floating point number * latitude/longitude data pairs. Populates msg.location with these. * Assumes that the msg object will always have exifData available as msg.exif. * Assume that the GPS data saved into Exif provides a valid value */ function addMsgLocationDataFromExifGPSData(msg,val) { var gpsData = msg.exif.gps; // declaring variable purely to make checks more readable if (gpsData.GPSAltitude) { /* istanbul ignore else */ if (!msg.location) { msg.location = {}; } msg.location.alt = gpsData.GPSAltitude; } if (gpsData.GPSLatitudeRef && gpsData.GPSLatitude && gpsData.GPSLongitudeRef && gpsData.GPSLongitude) { // location can be determined, OK // The data provided in Exif is in degrees, minutes, seconds, this is to be converted into a single floating point degree if (gpsData.GPSLatitude.length === 3) { // OK to convert latitude if (gpsData.GPSLongitude.length === 3) { // OK to convert longitude var latitude = convertDegreesMinutesSecondsToDecimals(gpsData.GPSLatitude[0], gpsData.GPSLatitude[1], gpsData.GPSLatitude[2]); latitude = Math.round(latitude * 100000)/100000; // 5dp is approx 1m resolution... // (N)orth means positive latitude, (S)outh means negative latitude if (gpsData.GPSLatitudeRef.toString() === 'S' || gpsData.GPSLatitudeRef.toString() === 's') { latitude = latitude * -1; } var longitude = convertDegreesMinutesSecondsToDecimals(gpsData.GPSLongitude[0], gpsData.GPSLongitude[1], gpsData.GPSLongitude[2]); longitude = Math.round(longitude * 100000)/100000; // 5dp is approx 1m resolution... // (E)ast means positive longitude, (W)est means negative longitude if (gpsData.GPSLongitudeRef.toString() === 'W' || gpsData.GPSLongitudeRef.toString() === 'w') { longitude = longitude * -1; } // Create location property if not exists if (!msg.location) { msg.location = {}; } msg.location.lat = latitude; msg.location.lon = longitude; } else { node.log("Invalid longitude data, no location information has been added to the message."); } } else { node.log("Invalid latitude data, no location information has been added to the message."); } } else { node.log("The location of this image cannot be determined safely so no location information has been added to the message."); } msg.location.arc = { ranges: [500,1000,2000], pan: gpsData.GPSImgDirection, fov: (2 * Math.atan(36 / (2 * msg.exif.exif.FocalLengthIn35mmFormat)) * 180 / Math.PI), color: '#910000' } msg.location.icon = "fa-camera"; var na; if (val.hasOwnProperty("name")) { na = val.name; } else if (msg.hasOwnProperty("filename")) { na = msg.filename.split('/').pop(); } else { na = msg.exif.image.Make+"_"+msg.exif.image.ModifyDate; } msg.location.name = na; msg.location.layer = "Images"; msg.location.popup = '' } this.on("input", function(msg) { if (node.mode === "worldmap" && (msg.payload.action !== "file" || msg.payload.type.indexOf("image") === -1)) { return; } // in case worldmap-in not filtered. try { var value = RED.util.getMessageProperty(msg,node.property); if (value !== undefined) { if (typeof value === "string") { // it must be a base64 encoded inline image type if (value.indexOf('data:image') !== -1) { value = new Buffer.from(value.replace(/^data:image\/[a-z]+;base64,/, ""), 'base64'); } } if (Buffer.isBuffer(value)) { // or a proper jpg buffer new ExifImage({ image:value }, function (error, exifData) { if (error) { if (node.mode !== "worldmap") { node.log(error.toString()); } else { msg.location = {name:msg.payload.name, lat:msg.payload.lat, lon:msg.payload.lon, layer:"Images", icon:"fa-camera", draggable:true}; msg.location.popup = '
'; } } else { if (exifData) { msg.exif = exifData; if ((exifData.hasOwnProperty("gps")) && (Object.keys(exifData.gps).length !== 0)) { addMsgLocationDataFromExifGPSData(msg,value); } //else { node.log("The incoming image did not contain Exif GPS data."); } } else { node.warn("The incoming image did not contain any Exif data, nothing to do."); } } if (node.mode === "worldmap") { msg.payload = msg.location; delete msg.location; } node.send(msg); }); } else { node.error("Invalid payload received, the Exif node cannot proceed, no messages sent.",msg); return; } } else { node.warn("No input received, the Exif node cannot proceed, no messages sent.",msg); return; } } catch (error) { node.error("An error occurred while extracting Exif information. Please check the log for details.",msg); node.log('Error: '+error.message); return; } }); } RED.nodes.registerType("exif",ExifNode); }