Photoshop Javascript : load selection of opaque pixels but not the transparent pixels.

[billouparis]

Photoshop Javascript : load selection of opaque pixels but not the transparent pixels of a layer.

I really despair to achieve this in a simple javascript script.

I kinda understood I needed to first load a channel, and then perform a selection from this channel, but I just failed doing this. I don't know how to get the corresponding channel that contains the transparent pixels of the current layer.

The original file is a PNG, it has a single layer.

There is no alpha channel, only R, G and B, although the image has transparent areas.

When I go to select, load Selection, Photoshop suggests by default a channel called layer_name+" Transparency",

therefore I tried something like:

doc.selection.load(doc.channels[layer_name + "Transparency"], SelectionType.EXTEND);

But this just failed.

I think I don't understand the way I am supposed to work with selections and channels

Thanks for any help!

Bill

[Chuck Uebele]

Can you load the selection by ctrl/cmd clicking on the layer's thumbnail in the layer panel?

[billouparis]

Hello Chuck,

yes I can.

[Kukurykus · Accepted solution]

sTT = stringIDToTypeID;
(ref1 = new ActionReference()).putProperty(c = sTT('channel'), sTT('selection'));
(dsc = new ActionDescriptor()).putReference(sTT('null'), ref1);
(ref2 = new ActionReference()).putEnumerated(c, c, sTT('transparencyEnum'))
dsc.putReference(sTT('to'), ref2), executeAction(sTT('set'), dsc);

[billouparis]

This seems to be working.

Can you tell me what it does exactly, and how you came up with this solution?

Also I would like to get the coodinates of the bounding box around this selection, can I easily find them?

Can I associate this selection to a selection object in javascript?

Thank you!

Bill

[billouparis]

I found out what I needed

Thank you all!

Bill

[Kukurykus]

You can use ScriptListener to get similar code.

Bounding box coordinates you're taking using:

activeDocument.selection.bounds

I don't know what you mean by last question?

[JJMack]

A Selection includes feathering It may well not a B/W cutout there the gray area. Its a grayscale channel