ここに別のアプローチがあります... 注:icnsファイルが作成される前に、元のpngが予想されるサイズにスケーリングされます。元の png のコピーを保持する場合は、最初に複製します。スクリプトに行を追加して、自動的に行うこともできます。
property expectedSizes : {16, 32, 48, 128, 256, 512, 1024, 9999999}
set myFiles to choose file with multiple selections allowed
repeat with aFile in myFiles
tell application "System Events" to set bPath to POSIX path of (container of aFile)
set newPath to bPath & "/" & bName(aFile) & ".icns" as text
set aFile to quoted form of (POSIX path of aFile)
set {W, H} to {paragraph 1, paragraph 2} of (do shell script "sips -g pixelWidth -g pixelHeight " & aFile & " | grep -Eo [0-9]*$")
set {W, H} to {W as number, H as number}
if W > H then
set W to eSize(W)
do shell script "sips " & aFile & " -Z " & W & " -p " & W & space & W & " --padColor FFFFFF -i"
delay 1
else if H > W then
set H to eSize(H)
do shell script "sips " & aFile & " -Z " & H & " -p " & H & space & H & " --padColor FFFFFF -i"
delay 1
-- H = W but not in expected sizes
else if H is not in expectedSizes then
set H to eSize(H)
do shell script "sips " & aFile & " -Z " & H & " -p " & H & space & H & " --padColor FFFFFF -i"
delay 1
end if
do shell script "sips -s format icns " & aFile & " --out " & quoted form of newPath
end repeat
on bName(theFile)
tell application "Finder" to set {name:fileName, name extension:nameExtension} to theFile
set baseName to text 1 thru ((get offset of "." & nameExtension in fileName) - 1) of fileName
end bName
on eSize(lDimen)
repeat with i from 1 to 8
if lDimen < item i of expectedSizes then return item (i - 1) of expectedSizes
end repeat
end eSize