Delete all the channels faster

[jboissinot]

Hi,

I use the activeDocument.channels.removeAll() function for deleting all the channels, it works well but can be long.

I have a 6K PSD file with 12 extra channels and it takes 2 min to remove them all.

I'm looking for a way to delete all the channels faster.

I tried with actions but I don't achieve to speed up this step.

Is it possible to delete all the channels like the "Delete Hidden Layers" action which is quickly even with a huge PSD file containing many layers ? Or anything else ? If you have any idea or solution.

Thanks

[c.pfaffenbichler]

You could do a saveAs and exclude the channels (PhotoshopSaveOptions.alphaChannels) – but I’m not sure it is much faster and you would have to replace and close the original file, I guess.

[jboissinot]

Yes it can be a solution. But I'm doing a clean-up of a PSD file before doing some export actions. It would be useful to have the possibility to duplicate a document without channels.

Back to my problem, if I drag&drop all the channels I have selected by hand, it's fast. I could do this with an action but I need the channels name, and the problem is that parsing the channels is so long because of it gets channel objects.

[Michael_L_Hale]

The code below uses the Action Manager API to remove alpha and spot channels from a document. It should be faster than the DOM and as fast as possible with a script.

function deleteAlphaAndSpotChannels(){
     function isAlphaOrSpotChannel(){
     var ref = new ActionReference();
     ref.putEnumerated( charIDToTypeID("Chnl"), charIDToTypeID("Ordn"), charIDToTypeID("Trgt") ); 
     return executeActionGet(ref).hasKey( stringIDToTypeID('ID') );
     }
     function deleteChannelByIndex( idx ){
          var desc = new ActionDescriptor();
               var ref = new ActionReference();
               ref.putIndex(charIDToTypeID( "Chnl" ), idx )
          desc.putReference( charIDToTypeID( "null" ), ref );
          executeAction( charIDToTypeID( "Dlt " ), desc, DialogModes.NO );
     }
     function getNumberOfChannels(){     
          var ref = new ActionReference();
          ref.putEnumerated( charIDToTypeID("Dcmn"), charIDToTypeID("Ordn"), charIDToTypeID("Trgt") ); 
          return executeActionGet(ref).getInteger( stringIDToTypeID('numberOfChannels'))// does not count layer masks
     }
     function numberOfComponentChannels(){     
          var ref = new ActionReference();
          ref.putEnumerated( charIDToTypeID("Dcmn"), charIDToTypeID("Ordn"), charIDToTypeID("Trgt") ); 
          var mode = typeIDToStringID( executeActionGet( ref ).getEnumerationValue( stringIDToTypeID('mode') ) );
          var numberOfComponentChannels = 4;// set default for CMYK
          switch ( mode ){
               case "RGBColor":
                    numberOfComponentChannels = 3;
                    break;
               case "labColor":
                    numberOfComponentChannels = 3;
                    break;
               case "grayScale":
                    numberOfComponentChannels = 1;
                    break;
          }
          return numberOfComponentChannels;
     }
     while( getNumberOfChannels() > numberOfComponentChannels() ){
          makeChannelActiveByIndex( getNumberOfChannels(), false );
          if( isAlphaOrSpotChannel() ){
               deleteChannelByIndex( getNumberOfChannels() );
          }
     }
     function makeChannelActiveByIndex( idx, visible ){
          var desc = new ActionDescriptor();
               var ref = new ActionReference();
               ref.putIndex(charIDToTypeID( "Chnl" ), idx)
               desc.putReference( charIDToTypeID( "null" ), ref );
               desc.putBoolean( charIDToTypeID( "MkVs" ), visible );
          executeAction( charIDToTypeID( "slct" ), desc, DialogModes.NO );
     }
}
deleteAlphaAndSpotChannels();

[JohnVo]

yeah it's amazing fast!

a question should be in *.js , ansi or unicode?

windows version

thanks

[Michael_L_Hale]

Although the .js extension will work Adobe recommends using .jsx. Save as plain text.

[JohnVo]

thanks

i use notepad++ , plain text is ansi

thank again!