Help with script saving PNG.. currently only says as 72DPI.. how can I make it retain the DPI?

[abUSER23]

Hi there... I have a script I can run that will save a PNG of the current visiable layers, and then increment the file name. I use this script inside actions to allow me ot save out files during edits.

This is my current script.

var saveFolder = new Folder( "d:\\PathTo\\SaveFolder" );  
var saveExt = 'png';  
var saveSufixStart = '_';  
var saveSufixLength = 3;  
// End of user options   
//==========================================   
  
var docName = decodeURI ( activeDocument.name );  
docName = docName.match( /(.*)(\.[^\.]+)/ ) ? docName = docName.match( /(.*)(\.[^\.]+)/ ) : docName = [ docName, docName, undefined ];  
var saveName = docName[ 1 ]; // activeDocument name with out ext  
var files = saveFolder.getFiles( saveName + '*.' + saveExt );// get an array of files matching doc name prefix  
  
var saveNumber = files.length + 1;  
//alert("New file number: " + zeroPad( saveNumber, saveSufixLength ));  
var saveFile = new File( saveFolder + '/' + saveName + '_' + zeroPad( saveNumber, saveSufixLength ) + '.' + saveExt );  
sfwPNG24( saveFile, 80 );  
//activeDocument.saveAs( saveFile, jpgSaveOptions ,true ,Extension.LOWERCASE);  
  
function zeroPad ( num, digit ) {   
   var tmp = num.toString();   
   while (tmp.length < digit) { tmp = "0" + tmp;}   
   return tmp;  
}  
  
function sfwPNG24( saveFile, quality ) {  
    var pngOpts = new ExportOptionsSaveForWeb;  
    pngOpts.format = SaveDocumentType.PNG;  
    pngOpts.PNG8 = false;  
    pngOpts.transparency = true;  
    pngOpts.interlaced = false;  
    pngOpts.quality = quality;  
    activeDocument.exportDocument( new File( saveFile ), ExportType.SAVEFORWEB ,pngOpts);  
}  

I had this made for me as I have zero understanding about scripting and programming.. I think the problem is the "ExportType.SAVEFORWEB"?

Basically if I have

• 800DPI image
• 2119x2883 pix
• 6.73x9.15cm

I want it to stay that way... at the moment the script is outputting this...

• 72DPI
• 2119x2883 pix
• 74.75x101.71cm

How would I midify this script to retain the existing DPI and print size of a document?

Thank you for any help you may have.

[Stephen_A_Marsh]

That is correct, the Save for Web code needs to be swapped out for a standard Save As code in order to retain the resolution metadata.

Just for the record, the PNG-pHYs specification does not use pixels per inch, it uses pixels per meter, so the saved resolution will be 31496 ppm, which Photoshop "translates" into a PPI value for display (314.96 cm x 2.54 cm [metric to inch] = 799.9984 ppi, rounded to 800 ppi).

[abUSER23]

thank you... but I have no diea how to chaneg this... what would the correct code be for the behaviour I am looking for?

[Stephen_A_Marsh]

I'll look at the code this evening if nobody has helped before then.

[abUSER23]

thanks for your time.

[Stephen_A_Marsh · Accepted solution]

@abUSER23 – OK, I managed to look at this earlier than expected, try this:

var saveFolder = new Folder( "d:\\PathTo\\SaveFolder" );  
var saveExt = 'png';  
var saveSufixStart = '_';  
var saveSufixLength = 3;  
// End of user options   
  
var docName = decodeURI ( activeDocument.name );  
docName = docName.match( /(.*)(\.[^\.]+)/ ) ? docName = docName.match( /(.*)(\.[^\.]+)/ ) : docName = [ docName, docName, undefined ];  
var saveName = docName[ 1 ]; // activeDocument name with out ext  
var files = saveFolder.getFiles( saveName + '*.' + saveExt );// get an array of files matching doc name prefix  
  
var saveNumber = files.length + 1;  
//alert("New file number: " + zeroPad( saveNumber, saveSufixLength ));  
var saveFile = new File( saveFolder + '/' + saveName + '_' + zeroPad( saveNumber, saveSufixLength ) + '.' + saveExt );  
saveAsPNG(saveFile, 9);  
  
function zeroPad ( num, digit ) {   
   var tmp = num.toString();   
   while (tmp.length < digit) { tmp = "0" + tmp;}   
   return tmp;  
}

function saveAsPNG(saveFile, quality) { 
    pngOpts = new PNGSaveOptions();
    pngOpts.compression = quality; //0-9
    pngOpts.interlaced = false;
    activeDocument.saveAs(File(saveFile), pngOpts, true); 
}

[Stephen_A_Marsh]

@abUSER23 - So how did the updated script go?

[abUSER23]

Sorry... for some reason I missed the notification email that there was a new reply.

I just tested the script and it apears to bne working as I hoped. Just saved a 800DPI image.. and the resulting png was the correct size,pixel count,dpi.... thanks man.

[Stephen_A_Marsh]

You're welcome, notifications have been spotty for weeks, which is why I followed up.