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sz20044
sz20044
Known Participant
March 28, 2019
Answered

How to get bounding box of a layer mask?

  • March 28, 2019
  • 1 reply
  • 4055 views

I am trying to get the bounding box of a layer mask, as well as a group containing layer masks... yet no matter what I do, it always returns the full size of the canvas 0,0 to max.  Is there a way to do this via javascript?  I would think Photoshop is smart enough to spit this back, considering I can scale a layer mask and the mask portion is scaled, not the entire canvas size.

This topic has been closed for replies.
Correct answer r-bin

I appreciate the help.  Sorry guys, I am not an avid Photoshop or Javascript expert here in scripting.

I have tried your selection script and it errors out if I fill in the mask channel name.  I have also tried just RGB and I get the same error:

Error: Illegal Argument

Tried:

selection_from_channel("RGB");

//selection_from_channel("Msk ");

and

selection_from_channel("HL Mask");      <--- Name of the Layer Mask Channel

//selection_from_channel("Msk ");


sz20044 

I appreciate the help.  Sorry guys, I am not an avid Photoshop or Javascript expert here in scripting.

I have tried your selection script and it errors out if I fill in the mask channel name.  I have also tried just RGB and I get the same error:

Error: Illegal Argument

Tried:

selection_from_channel("RGB");

//selection_from_channel("Msk ");

and

selection_from_channel("HL Mask");      <--- Name of the Layer Mask Channel

//selection_from_channel("Msk ");

This is not a channel name, but a four-character CharID for standard channels.

You had to do it that way.
if (selection_from_channel("Msk "))
    {
    try { var b = activeDocument.selection.bounds; } catch(e) { alert("No selection");  }
    alert(b);
    }
function selection_from_channel(ch_name)
    {
    try {
        var d = new ActionDescriptor();
        var r1 = new ActionReference();
        var r2 = new ActionReference();
        r1.putProperty(charIDToTypeID("Chnl" ), charIDToTypeID("fsel"));
        r2.putEnumerated(charIDToTypeID("Chnl"), charIDToTypeID("Chnl"), charIDToTypeID(ch_name));
        d.putReference(charIDToTypeID("null"), r1);
        d.putReference(charIDToTypeID("T   "), r2);
        executeAction(charIDToTypeID("setd"), d, DialogModes.NO);
        return true;
        }
    catch(e) { alert("No mask"); return false; }
    }

You can rewrite the function to use more understandable StringID

if (selection_from_channel("mask"))
    {
    try { var b = activeDocument.selection.bounds; } catch(e) { alert("No selection");  }
    alert(b);
    }
function selection_from_channel(ch_name)
    {
    try {
        var d = new ActionDescriptor();
        var r1 = new ActionReference();
        var r2 = new ActionReference();
        r1.putProperty(stringIDToTypeID("channel"), stringIDToTypeID("selection"));
        r2.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("channel"), stringIDToTypeID(ch_name));
        d.putReference(stringIDToTypeID("null"), r1);
        d.putReference(stringIDToTypeID("to"), r2);
        executeAction(stringIDToTypeID("set"), d, DialogModes.NO);
        return true;
        }
    catch(e) { alert("No mask"); return false; }
    }

1 reply

R
r-bin
Legend
March 28, 2019

1. Convert Mask channel to selection

2. Use selection.bounds

R
r-bin
Legend
March 29, 2019

Selection from any channel: Re: Selecting custom pixels

sz20044
sz20044Author
Known Participant
March 29, 2019

sz20044 

I appreciate the help.  Sorry guys, I am not an avid Photoshop or Javascript expert here in scripting.

I have tried your selection script and it errors out if I fill in the mask channel name.  I have also tried just RGB and I get the same error:

Error: Illegal Argument

Tried:

selection_from_channel("RGB");

//selection_from_channel("Msk ");

and

selection_from_channel("HL Mask");      <--- Name of the Layer Mask Channel

//selection_from_channel("Msk ");

This is not a channel name, but a four-character CharID for standard channels.

You had to do it that way.
if (selection_from_channel("Msk "))
    {
    try { var b = activeDocument.selection.bounds; } catch(e) { alert("No selection");  }
    alert(b);
    }
function selection_from_channel(ch_name)
    {
    try {
        var d = new ActionDescriptor();
        var r1 = new ActionReference();
        var r2 = new ActionReference();
        r1.putProperty(charIDToTypeID("Chnl" ), charIDToTypeID("fsel"));
        r2.putEnumerated(charIDToTypeID("Chnl"), charIDToTypeID("Chnl"), charIDToTypeID(ch_name));
        d.putReference(charIDToTypeID("null"), r1);
        d.putReference(charIDToTypeID("T   "), r2);
        executeAction(charIDToTypeID("setd"), d, DialogModes.NO);
        return true;
        }
    catch(e) { alert("No mask"); return false; }
    }

You can rewrite the function to use more understandable StringID

if (selection_from_channel("mask"))
    {
    try { var b = activeDocument.selection.bounds; } catch(e) { alert("No selection");  }
    alert(b);
    }
function selection_from_channel(ch_name)
    {
    try {
        var d = new ActionDescriptor();
        var r1 = new ActionReference();
        var r2 = new ActionReference();
        r1.putProperty(stringIDToTypeID("channel"), stringIDToTypeID("selection"));
        r2.putEnumerated(stringIDToTypeID("channel"), stringIDToTypeID("channel"), stringIDToTypeID(ch_name));
        d.putReference(stringIDToTypeID("null"), r1);
        d.putReference(stringIDToTypeID("to"), r2);
        executeAction(stringIDToTypeID("set"), d, DialogModes.NO);
        return true;
        }
    catch(e) { alert("No mask"); return false; }
    }


Thank you, this helps!

On this same note, is there an easy way to check if a particular group is one that contains these layer masks?  Obviously having to run different code for ones that do vs ones that don't.  I know I can check to see what the activeLayer type is (for example if it is a LayerSet) ... is there a way to check if that activeLayer is a mask or contains masks?

if(doc.activeLayer.typename == 'LayerSet')

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