ExtendScript CS6 doesn't handle GPS data properly

Question

I prefer to work in Photoshop and Bridge, rather than Lightroom.  I am currently using version CS6 on Windows 7 x64.  I occasionally need to update the title, description and/or GPS information of a photograph. (I have many photographs that predate GPS systems.)  I also maintain different several JPEG versions of each photograph generated from a base PSD with different cropping and resolutions that are intended for different purposes.  I wrote a Bridge script to check and update the metadata of all versions of one or more images in a batch after updating PSD metadata.  The script works very well except for the GPS latitude and longitude data.
The problem is that using the XMPMeta object that comes with ExtendScript Toolkit 3.8.0.13 (the latest version, I believe) the GPS coordinates are returned as string data in an "Adobe format", e.g. “35,24.3467N”. This format does not always accurately represent the underlying EXIF data.  (I have also written my own script for getting and setting the GPS data in Photoshop.)
Furthermore, comparisons between PSD and JPEG formats are impossible because XMPMeta.getProperty only returns up to two decimal places for minutes when querying a PSD file, whereas it returns up to four decimal places for JPEGs.  I have checked the actual EXIF GPS data for a PSD image and a JPEG image generated from that PSD with EXIFTool and the data is identical, but XMPMeta.getProperty returns “35,24.3467N” from the JPEG and “35,24.35N” from the PSD. Setting GPS coordinates using four decimal places produces the same EXIF data for both PSD and JPEG images.
The English translation of the “Exif Version 2.3” standard description for GPSLatitude states:
The latitude is expressed as three RATIONAL values giving the degrees, minutes, and seconds, respectively. If latitude isexpressed as degrees, minutes and seconds, a typical format would be dd/1,mm/1,ss/1. When degrees and minutes are used and, for example, fractions of minutes are given up to two decimal places, the format would be dd/1,mmmm/100,0/1.
It is clear that XMPMeta.getProperty does not always return a string that accurately represents the original EXIF data and it can be inconsistent between PSD and JPEG images.
Is there some way to obtain an accurate representation of GPS data using ExtendScript?
...Jim

Answer 1

I have seen some Photoshop Scripts on the Web the retrieve and use the exif GPG data.   But from what you write I would think your doing the same as those scripts do. Something like this:
// Open Map from GPS Location.jsx
// Version 1.0
// Shaun Ivory ([email protected])
// Feel free to modify this script.  If you do anything interesting with it,
// please let me know.
// JJMack I just used my sledge hammer on Shaun's Photoshop script
// I sucked in his include file and removed his include statement
// then I commented out his dialog and just Goolge Map the GPS location
<javascriptresource>
<about>$$$/JavaScripts/GoogleMapGPS/About=JJMack's Google Map GPS.^r^rCopyright 2014 Mouseprints.^r^rScript utility for action.^rNOTE:Modified Shaun's Ivory just Google Map GPS location</about>
<category>JJMack's Action Utility</category>
</javascriptresource>
// Constants which identify the different mapping sites
c_MapWebsites =
    "google",
    "mappoint",
    "virtualearth"
var c_nDefaultMapWebsiteIndex = 2;
var c_strTemporaryUrlFile = "~/TemporaryPhotoshopMapUrl.url";
var c_strPhotoCaption = "Photo%20Location";
// EXIF constants
c_ExifGpsLatitudeRef   = "GPS Latitude Ref"
c_ExifGpsLatitude      = "GPS Latitude"
c_ExifGpsLongitudeRef  = "GPS Longitude Ref"
c_ExifGpsLongitude     = "GPS Longitude"
c_ExifGpsAltitudeRef   = "GPS Altitude Ref"
c_ExifGpsAltitude      = "GPS Altitude"
c_ExifGpsTimeStamp     = "GPS Time Stamp"
c_ExifMake             = "Make"
c_ExifModel            = "Model"
c_ExifExposureTime     = "Exposure Time"
c_ExifAperture         = "F-Stop"
c_ExifExposureProgram  = "Exposure Program"
c_ExifIsoSpeedRating   = "ISO Speed Ratings"
c_ExifDateTimeOriginal = "Date Time Original"
c_ExifMaxApertureValue = "Max Aperture Value"
c_ExifMeteringMode     = "Metering Mode"
c_ExifLightSource      = "Light Source"
c_ExifFlash            = "Flash"
c_ExifFocalLength      = "Focal Length"
c_ExifColorSpace       = "Color Space"
c_ExifWidth            = "Pixel X Dimension"
c_ExifHeight           = "Pixel Y Dimension"
function GetRawExifValueIfPresent(strExifValueName)
    // Empty string means it wasn't found
    var strResult = new String("");
    // Make sure there is a current document
    if (app.documents.length)
        // Loop through each element in the EXIF properties array
        for (nCurrentElement = 0, nCount = 0; nCurrentElement < activeDocument.info.exif.length; ++nCurrentElement)
            // Get the current element as a string
            var strCurrentRecord = new String(activeDocument.info.exif[nCurrentElement]);
            // Find the first comma
            var nComma = strCurrentRecord.indexOf(",");
            if (nComma >= 0)
                // Everything before the comma is the field name
                var strCurrentExifName = strCurrentRecord.substr(0, nComma);
                // Is it a valid string?
                if (strCurrentExifName.length)
                    // Is this our element?
                    if (strCurrentExifName == strExifValueName)
                        // Everything after the comma is the value, so
                        // save it and exit the loop
                        strResult = strCurrentRecord.substr(nComma + 1);
                        break;
    return strResult;
// Convert a Photoshop latitude or longitude, formatted like
// this:
//      Example: 47.00 38.00' 33.60"
// to the decimal form:
//      Example: 47.642667
// It returns an empty string if the string is in an unexpected
// form.
function ConvertLatitudeOrLongitudeToDecimal(strLatLong)
    var nResult = 0.0;
    // Copy the input string
    var strSource = new String(strLatLong);
    // Find the first space
    nIndex = strSource.indexOf(" ");
    if (nIndex >= 0)
        // Copy up to the first space
        strDegrees = strSource.substr(0, nIndex);
        // Skip this part, plus the space
        strSource = strSource.substr(nIndex + 1);
        // Find the tick mark
        nIndex = strSource.indexOf("'");
        if (nIndex >= 0)
            // Copy up to the tick mark
            strMinutes = strSource.substr(0, nIndex);
            // Skip this chunk, plus the tick and space
            strSource = strSource.substr(nIndex + 2);
            // Find the seconds mark: "
            nIndex = strSource.indexOf("\"");
            if (nIndex >= 0)
                // Copy up to the seconds
                strSeconds = strSource.substr(0, nIndex);
                // Convert to numbers
                var nDegrees = parseFloat(strDegrees);
                var nMinutes = parseFloat(strMinutes);
                var nSeconds = parseFloat(strSeconds);
                // Use the correct symbols
                nResult = nDegrees + (nMinutes / 60.0) + (nSeconds / 3600.0);
    return nResult;
function GetDecimalLatitudeOrLongitude(strExifLatOrLong, strExifLatOrLongRef, strResult)
    var strResult = "";
    // Get the exif values
    strLatOrLong = GetRawExifValueIfPresent(strExifLatOrLong);
    strLatOrLongRef = GetRawExifValueIfPresent(strExifLatOrLongRef);
    // If we were able to read them
    if (strLatOrLong.length && strLatOrLongRef.length)
        // Parse and convert to a decimal
        var nResult = ConvertLatitudeOrLongitudeToDecimal(strLatOrLong);
        // If we are in the southern or western hemisphere, negate the result
        if (strLatOrLongRef[0] == 'S' || strLatOrLongRef[0] == 'W')
            nResult *= -1;
        strResult = nResult.toString();
    return strResult;
function CreateGoogleMapsUrl(strLatitude, strLongitude)
    return "http://maps.google.com/maps?ll=" + strLatitude + "," + strLongitude + "&spn=0.01,0.01";
function CreateMappointUrl(strLatitude, strLongitude)
    return "http://mappoint.msn.com/map.aspx?L=USA&C=" + strLatitude + "%2c" + strLongitude + "&A=50&P=|" + strLatitude + "%2c" + strLongitude + "|39|" + c_strPhotoCaption +"|L1|"
function CreateVirtualEarthUrl(strLatitude, strLongitude)
    return "http://virtualearth.msn.com/default.aspx?v=2&style=h&lvl=17&cp=" + strLatitude + "~" + strLongitude + "&sp=an." + strLatitude + "_" + strLongitude + "_" + c_strPhotoCaption + "_";
function CMapSiteSelection()
    // Initialize default map provider
    this.Site = c_MapWebsites[c_nDefaultMapWebsiteIndex];
    return this;
function ShowMyDialog(strLatitude, strLongitude)
    // Use the default website
    var strCurrentSite = c_MapWebsites[c_nDefaultMapWebsiteIndex];
    dlgMain = new Window("dialog", "Choose a Map Website");
    // Add the top group
    dlgMain.TopGroup = dlgMain.add("group");
  dlgMain.TopGroup.orientation = "row";
  dlgMain.TopGroup.alignChildren = "top";
  dlgMain.TopGroup.alignment = "fill";
    // Add the left group
    dlgMain.TopGroup.LeftGroup = dlgMain.TopGroup.add("group");
    dlgMain.TopGroup.LeftGroup.orientation = "column";
    dlgMain.TopGroup.LeftGroup.alignChildren = "left";
    dlgMain.TopGroup.LeftGroup.alignment = "fill";
    dlgMain.AspectRatioGroup = dlgMain.TopGroup.LeftGroup.add("panel", undefined, "Map Website");
    dlgMain.AspectRatioGroup.alignment = "fill";
    dlgMain.AspectRatioGroup.orientation = "column";
    dlgMain.AspectRatioGroup.alignChildren = "left";
    // Add radio buttons
    dlgMain.virtualEarth = dlgMain.AspectRatioGroup.add("radiobutton", undefined, "Windows Live Local (aka Virtual Earth)");
    dlgMain.virtualEarth.onClick = function virtualEarthOnClick()
        strCurrentSite = "virtualearth";
    dlgMain.mappoint = dlgMain.AspectRatioGroup.add("radiobutton", undefined, "MSN Maps && Directions (aka MapPoint)");
    dlgMain.mappoint.onClick = function mappointOnClick()
        strCurrentSite = "mappoint";
    dlgMain.google = dlgMain.AspectRatioGroup.add("radiobutton", undefined, "Google Local (aka Google Maps)");
    dlgMain.google.onClick = function googleOnClick()
        strCurrentSite = "google";
    // Set the checked radio button
    if (strCurrentSite == "google")
        dlgMain.google.value = true;
    else if (strCurrentSite == "mappoint")
        dlgMain.mappoint.value = true;
    else
        dlgMain.virtualEarth.value = true;
    // Add the button group
    dlgMain.TopGroup.RightGroup = dlgMain.TopGroup.add("group");
    dlgMain.TopGroup.RightGroup.orientation = "column";
    dlgMain.TopGroup.RightGroup.alignChildren = "left";
    dlgMain.TopGroup.RightGroup.alignment = "fill";
    // Add the buttons
    dlgMain.btnOpenSite = dlgMain.TopGroup.RightGroup.add("button", undefined, "Open");
    dlgMain.btnClose = dlgMain.TopGroup.RightGroup.add("button", undefined, "Exit");
    dlgMain.btnClose.onClick = function()
        dlgMain.close(true);
    dlgMain.btnOpenSite.onClick = function()
        // Which website?
        var strUrl = "";
        switch (strCurrentSite)
        case "mappoint":
            strUrl = CreateMappointUrl(strLatitude, strLongitude);
            break;
        case "google":
            strUrl = CreateGoogleMapsUrl(strLatitude, strLongitude);
            break;
        case "virtualearth":
        default:
            strUrl = CreateVirtualEarthUrl(strLatitude, strLongitude);
            break;
        // Create the URL file and launch it
        var fileUrlShortcut = new File(c_strTemporaryUrlFile);
        fileUrlShortcut.open('w');
        fileUrlShortcut.writeln("[InternetShortcut]")
        fileUrlShortcut.writeln("URL=" + strUrl);
        fileUrlShortcut.execute();
    // Set the button characteristics
    dlgMain.cancelElement = dlgMain.btnClose;
    dlgMain.defaultElement = dlgMain.btnOpenSite;
    dlgMain.center();
    return dlgMain.show();
function GoogleMap(strLatitude, strLongitude)
  strUrl = CreateGoogleMapsUrl(strLatitude, strLongitude)
  try{
  var URL = new File(Folder.temp + "/GoogleMapIt.html");
  URL.open("w");
  URL.writeln('<html><HEAD><meta HTTP-EQUIV="REFRESH" content="0; ' + strUrl + ' "></HEAD></HTML>');
  URL.close();
  URL.execute();   // The temp file is created but this fails to open the users default browser using Photoshop CC prior Photoshop versions work
  }catch(e){
  alert("Error, Can Not Open.");
function OpenMapUrl()
    // Get the latitude
    var strDecimalLatitude = GetDecimalLatitudeOrLongitude(c_ExifGpsLatitude, c_ExifGpsLatitudeRef);
    if (strDecimalLatitude.length)
        // Get the longitude
        var strDecimalLongitude = GetDecimalLatitudeOrLongitude(c_ExifGpsLongitude, c_ExifGpsLongitudeRef);
        if (strDecimalLongitude.length)
            //ShowMyDialog(strDecimalLatitude, strDecimalLongitude);
  GoogleMap(strDecimalLatitude, strDecimalLongitude);
function Main()
    if (app.documents.length > 0)
        OpenMapUrl();
    else
        alert("You don't have an image opened.  Please open an image before running this script.");
Main();