Scripting Photoshop
For the first time, I needed to script the exporting of images from Photoshop documents. Normally, I would use my scriptable photo editing tool of choice for this: Acorn, but Acorn was unable to open these particular Photoshop documents and retain full fidelity.
So, I had to learn to script Photoshop.
My task is to convert a document containing an MRI image of the human brain and many layers highlighting structures within these MRI images into a series of PNG files.
Opening Documents
The first problem is that Photoshop’s open command does not return a reference to the opened document. The workaround is this:
set theDocument to choose file -- Get the Photoshop document to open
tell application "System Events"
set theDocumentName to name of theDocument -- Get the document's name
set theDocument to path of theDocument -- Photoshop does not accept the aliases returned by `choose file`, we need an HFS path
end tell
tell application "Adobe Photoshop CC 2019"
-- Open the document if its not already open
if not (exists document theDocumentName) then
open file theDocument
end if
tell document theDocumentName
-- commands directed at the opened document
get name
end tell
end tell
Manipulating Layers & Exporting
My task involved exporting individual layers from my Photoshop document. I accomplish this like this:
set exportFolder to "Users:mall:Desktop:Exported Images:" -- HFS path to the folder where the image should be written
set layersToShow to {"Background", "Lateral Fissure"}
tell application "Adobe Photoshop CC 2019"
tell document theDocumentName
-- Prepare the layers for export
set visible of every layer to false -- turn off all layers
set visible of layers whose name is in layersToShow to true -- turn on the layers I want
-- Export the visible layers as a PNG file
export as save for web in file (exportFolder & "Lateral Fissure.png") with options {class:save for web export options, web format:PNG}
end tell
end tell
Closing Documents
And finally, when you are done with the document, you need to close it:
tell application "Adobe Photoshop CC 2019"
tell document theDocumentName
close saving no -- use `close saving yes` to save changes to your Photoshop document
end tell
end tell