image processing with applescript III

a little while ago we had a look at how to use applescript and sips to scale image files without the hassle of going through photoshop – see image processing with applescript II. open the terminal application, type in “man sips” and you’ll find there’s a whole bunch stuff you can do with images without ever opening photoshop — pretty cool :
screen grab of the sips manual in terminal

… but you can play around with all that another time. today we’re focussing on extending the functionality of the image resize script from that post to make it a little more user friendly. rather than a have script that’s hard-wired to scale images to 500px high, we’ll create one that can accept user input, so that the pixel dimensions can be changed each time the script is run.

to do that we need to first create a dialog. unfortunately the dialog possibilities with standard applescript are pretty crap — particularly when compared to all the options available to applescript dialogs in InDesign – border panels, columns, rows, checkbox controls, dropdowns, enabling groups, event listeners, comboboxes, editboxes, radiobuttons, etc.

here is all you get with standard dialogs :
screen grab of dialog entry in standard additions dictionary

well, although that’s pretty diabolical, it’s still enough for what we need. here’s the first part of the script :

display dialog "enter the pixel ratio you want these scaled to" with title "resize images" default answer "800" buttons {"cancel", "wide", "high"} default button 1
set mgResult to result
set mgText to text returned of mgResult
set mgButton to button returned of mgResult

that’ll give us a dialog something like this :
screen grab of resize images script dialog

… which gives us two pieces of information — the text entered and the button clicked – both captured into variables. if you want to make the script fool-proof, you’ll need to add some error handling to ensure that the text entered is an integer. but in its current form, the script assumes that the user is not an idiot.

the next part of the script creates a subfolder in the finder to save the transformed images into (this script creates duplicates of the original images rather than overwriting the originals with the resized versions) – then creates a reference to that folder for use later in the script :

set mgFolder to (mgText & "px") as string

tell application "Finder"
  set mgItems to selection
  set mgContainer to container of item 1 of mgItems
  set mgContainer to mgContainer as alias
  if (exists folder mgFolder of folder mgContainer) is false then
    make folder at mgContainer with properties {name:mgFolder}
  end if
end tell

set mgFinalFolder to mgContainer & mgFolder & ":" as string

then comes the key to the adaptability of this script — altering the final sips command based on the user’s choices in the dialog. we capture this into a variable called mgScriptString :

if mgButton is "high" then
  set mgScriptString to "sips --resampleHeight '" & mgText & "' "
  if mgButton is "wide" then
    set mgScriptString to "sips --resampleWidth '" & mgText & "' "
  end if
end if

the rest of the script is pretty much as per the previous post except that we insert the mgScriptString variable into the do shell script command :

repeat with mgItem in mgItems
  set mgName to name of mgItem
  set mgFinalpath to mgFinalFolder & mgName
  set mgPath to POSIX path of (mgItem as text)
  --convert mgFinalpath to POSIX form
  set text item delimiters to ":"
  set mgFinalpath to text items 2 thru -1 of mgFinalpath
  set text item delimiters to "/"
  set mgFinalpath to mgFinalpath as string
  set text item delimiters to ""
  set mgFinalpath to quoted form of mgFinalpath
    do shell script mgScriptString & quoted form of POSIX path of mgPath & " --out " & mgFinalpath
    do shell script "sips -m '/System/Library/ColorSync/Profiles/sRGB Profile.icc' -i " & mgFinalpath
  end try
end repeat

wrap all that in an open handler (and delete the line “set mgItems to selection”) and you’ll have a script that looks like this :
screen grab of finished script

save that as an application and whack it in your sidebar. drag and drop as many images as you like onto the app — they’ll all be scaled quicker than you could do it through photoshop. don’t worry about accidentally dropping non-image files — these just get skipped.

you can also go here to get the complete image processing script.

have a good one

macgrunt icon