Can the "Description" metadata fields be deleted with a Photoshop Script?

[Chris S]

Any gurus here with Photoshop scripting knowledge that can help me clear out just the 4 metadata fields below with a Photoshop script?

• [EXIF] ImageDescription
• [XMP-dc] Description
• [IPTC] Caption-Abstract
• [XMP-Photoshop] DocumentAncestors

First, let me say that I know this can easily be done with the ExifTool code below:

exiftool -m -overwrite_original_in_place -EXIF:ImageDescription= -XMP:dc:Description= -IPTC:Caption-Abstract= [DIR]

While this works great for me, I would like to do this same thing with a Photoshop script, if possible, since all of the sites that will be using this don't have ExifTool. Also, with a script I can ensure it automatically gets checked/done when a file is opened/saved in Photoshop.

Below is the .jsx script I have so far:

function deleteUnwantedMetadata() {
    whatApp = String(app.name);
    if(whatApp.search("Photoshop") > 0)  {
        if(!documents.length) {
        alert("No open documents. Open a file to run script.")
        return;
        }
        if (ExternalObject.AdobeXMPScript == undefined) ExternalObject.AdobeXMPScript = new ExternalObject("lib:AdobeXMPScript");
        var xmp = new XMPMeta( activeDocument.xmpMetadata.rawData);
           xmp.deleteProperty(XMPConst.NS_PHOTOSHOP, "DocumentAncestors");
           if (xmp.doesArrayItemExist(XMPConst.NS_DC, "description", 1))
            {
                xmp.deleteArrayItem(XMPConst.NS_DC, "description", 1);
             }
            app.activeDocument.xmpMetadata.rawData = xmp.serialize();
         }
  }
 deleteUnwantedMetadata();

This script is invoked with the Photoshop Scripts Events Manager on Document Open.

Observations:

TIFF: Works as desired... all 4 fields are cleared.

PSD, PSB and JPG: 3 of the 4 fields ([EXIF]ImageDescription, [IPTC]Caption-Abstract and [XMP-Photoshop]DocumentAncestors) are cleared as I'd like. However, for these image formats, the data that was once in [EXIF]ImageDescription is now in [XMP-dc]Description.

I noticed that if I open the PSD, PSB and JPG files a second time and run through the script, then everything gets cleared out on these files as well.

If I add xmp.setLocalizedText(XMPConst.NS_DC, "description", null, "x-default", " "); below xmp.deleteArrayItem(XMPConst.NS_DC, "description", 1);. above, this will at least clear everything out and just include a space for the field, but would rather have the filed empty if possible (null doesn't appear to work here).

Assumptions:

I believe this has something to do with how the [EXIF]ImageDescription and [XMP-dc]Description work together, but not sure how to resolve. It would appear this script is clearing the [XMP-dc]Description, pulling the contents of the [EXIF]ImageDescription into it, which then clears the [EXIF]ImageDescription. Since [EXIF]ImageDescription was cleared by the script the first time, running it a second time puts that cleared value of the XMP-dcescription into itself, thereby freeing all of them up.

If my assumptions are correct, this leaves a few questions...

Questions:

1) Is there a way to amend the code to clear out the [EXIF]ImageDescription first? If so, how?

2) If not, any suggestions how I could modify the code to run only once to ensure the PSD/PSB/JPG is fixed the first time? I tried the two things below that didn't work:
- Called the function from within the script twice
- Added the script to 2 events (On Open & On Close)

PS: I don't want to delete all metadata, just these fields.

References:

Test image and .jsx script are attached for reference.

Posted similar question to PS-Scripts, Adobe Support Community and Stack Overflow... no solutions yet.

I found this post on Exiftool's forum that was helpful in understanding the interplay of the description fields.

 

[lumigraphics]

Adobe's XMP/EXIF implementation doesn't work with all metadata fields. Its FAR easier to use EXIFTool for this. I have written a numberŕof utility scripts but finally had to write an integration for Bridge/Photoshop and EXIFTool to actually deal with metadata the way I needed.