File abnormally huge (1.8GB) flat 24X24 350dpi how to reduce non-destructively

[Garret Moore]

This is a Photoshop file to print Giclée art so it is, of course, large, but this is a ginormously large file and I don't know how the PSD file is 6 times larger than other files the same size. It is flat, 350 dpi cannot have a reduction in print-size no effects or layers at all. I ran it through Lightroom to do some image processing as it was a 4X5 scanned of artwork to print. Physical size is 24" X 24" but has a wide white margin and the image is only 16" sq. Have I accumulated embedded processing information in Lightroom and Photoshop that is in the file itself and cannot be removed? I had to convert the file to PSB at 1.8 GB size was choking the system pipe a bit.
So the question: How can I reduce the file size while not reducing resolution, size, color information or anything that makes it a viable art print file? See image example to know it's printable qualities.

One answer I will try is converting it to a Tif or a PNG then bringing it back into a PSD hoping that nullifies the embedded data from processes. What do we think?

I've been a photoshop artist since 1992 and digital artist since 1983 previously to that.

 

[admin]

Hello and welcome to PSG.

A few things you can try:

• Uncheck the option "Maximize Compatibility". You can find this in 'Edit -> Preferences -> File Handling' if you have disabled the popup when saving. This can save a lot of file size.
• If you have out of bounds data you can select all and then crop image to remove this.
• As you have suggested, export the image in a lossless format, choose 'Metadata = None' to strip the EXIF and XMP data form the image. Then you can create a PSD from that file if you like, it should be smaller if you had a lot of metadata.
• Use a third party tool to completely strip the metadata if the image is still too large. ExifTool is one, there are other similar tools as well.

 

[Paul MR]

Another problem could be "DocumentAncestors" in the metadata, this can sometimes get Huge.
Here is a script to remove this field:-

#target photoshop;
var File1 = File.openDialog("Please select Image","*.*");
if(File1.exists) {
    removeAncestors( File1);
    alert("Please check file now");
    }

function removeAncestors( file){
if ( !ExternalObject.AdobeXMPScript ) ExternalObject.AdobeXMPScript = new ExternalObject('lib:AdobeXMPScript');
        var xmpf = new XMPFile( File(file).fsName, XMPConst.UNKNOWN, XMPConst.OPEN_FOR_UPDATE );
        var xmp = xmpf.getXMP();
        xmp.deleteProperty(XMPConst.NS_PHOTOSHOP, "DocumentAncestors");
      if (xmpf.canPutXMP( xmp )) {
         xmpf.putXMP( xmp );
      }
      xmpf.closeFile( XMPConst.CLOSE_UPDATE_SAFELY );
}

 

[thebestcpu]

Hi Garret
At 24 inches on a size at 350 ppi and 16bit depth would only be around 423 MB assuming to compression so you definitely have a of data lurking in there somewhere.
I do not know your workflow so sharing you file on a image sharing platform (e.g. dropbox) would make it much easier to confirm what is going on.
Without that a very common place for a lot of data to be hiding is alpha channels in the channels panel. Those do not go away when the image is flattened.
Neither do paths in the Paths panel yet those typically don't take up any room. You an go look in those two places manually and delete the alpha channels and paths and see where you are after that.
Metadata can hide a lot as well as already pointed out
Hope that helps
John Wheeler

 

[Garret Moore]

Hello and welcome to PSG.

A few things you can try:

• Uncheck the option "Maximize Compatibility". You can find this in 'Edit -> Preferences -> File Handling' if you have disabled the popup when saving. This can save a lot of file size.
• If you have out of bounds data you can select all and then crop the image to remove this.
• As you have suggested, export the image in a lossless format, choose 'Metadata = None' to strip the EXIF and XMP data from the image. Then you can create a PSD from that file if you like, it should be smaller if you had a lot of metadata.
• Use a third-party tool to completely strip the metadata if the image is still too large. ExifTool is one, there are other similar tools as well.

Thanks, The file has no out of bounds data, I usually expand or scrub the layer in all 4 directions when making the file. Hard to do now at this weight but a double-check can be done. I also select to boundary and "crop" to delete out-of-bound data.
I did export to a TIF to strip out any Photoshop specific information, then re-converted and overwrote the original PSD, but at this level, I don't know if there is inheritance with Tif due to layer information being supported in that of oldest image formats, but assumed no layer would squelch any inherited data. Tif convert did not help BTW. I am looking into the other suggestions but deep in production for an exhibition this week. Still a mystery I intend to solve and record for others experiencing this.

 

[Garret Moore]

Another problem could be "DocumentAncestors" in the metadata, this can sometimes get Huge.
Here is a script to remove this field:-

#target photoshop;
var File1 = File.openDialog("Please select Image","*.*");
if(File1.exists) {
    removeAncestors( File1);
    alert("Please check file now");
    }

function removeAncestors( file){
if ( !ExternalObject.AdobeXMPScript ) ExternalObject.AdobeXMPScript = new ExternalObject('lib:AdobeXMPScript');
        var xmpf = new XMPFile( File(file).fsName, XMPConst.UNKNOWN, XMPConst.OPEN_FOR_UPDATE );
        var xmp = xmpf.getXMP();
        xmp.deleteProperty(XMPConst.NS_PHOTOSHOP, "DocumentAncestors");
      if (xmpf.canPutXMP( xmp )) {
         xmpf.putXMP( xmp );
      }
      xmpf.closeFile( XMPConst.CLOSE_UPDATE_SAFELY );
}

Great! I'm from way back in the Dos and CPM era and know how this works, but will try this stripper code. No I am wondering how many other cool functions you can do at this level.

 

[Paul MR]

Hi Garret, there are lots that can be done via scripting, a few examples can be found here:- https://github.com/Paul-Riggott/PS-Scripts