How can I rasterize a PDF in Photoshop with specific pixel dimensions using Applescript?

Question

So I am trying to batch convert a bunch of PDFs to JPEG files as part of a larger Applescript, and I'm finding that some of the parameters in "PDF Open Options" are ignored. Namely, the "height", "width" and "constrain proportions" parameters.

This code is lifted directly from the Photoshop CS3 Scripting Guide (with filename changed, of course):

tell application "Adobe Photoshop CS3"
set myFilePath to alias "WABEL0457937:Users:Charles:Desktop:8925.pdf"
with timeout of 10000 seconds
open myFilePath as PDF with options {class:PDF open options, height:pixels 100, width:pixels 200, mode:RGB, resolution:72, use antialias:true, page:1, constrain proportions:false}
end timeout
end tell

In the resulting file, the "resolution" is correct, but the height and width are calculated using the PDF's original height and width multiplied by the resolution, and the image is constrained to the original proportions.

I thought it might be a collision with specifying the resolution and the height/width in pixels, so I tried omitting the resolution, but then it just defaults to 300.

Anyone else create a script that opens PDFs and run into this?

Answer 1

In looking at the AS Dictionary for Photoshop CS3, it states that the height, width, and constrain proportions properties for PDF open options have all been deprecated since CS2. (But leave it to Adobe to not clean up after themselves and thus furthering the inconsistencies of their interfaces.)

Answer 2

The way I worked out to do this was to determine the resolution of the PDF at 72DPI using a shell script, and then calculate the optimal resolution to rasterize to arrive at the desired dimensions.

(FYI: "str_replace" is a custom function to find and replace text in a string -- it's not a built-in Applescript function.)

set pageHeight to do shell script "/usr/bin/mdls -name kMDItemPageHeight " & quoted form of (POSIX path of this_item as string)
set pageHeight to my str_replace("kMDItemPageHeight = ", "", pageHeight)
set pageWidth to do shell script "/usr/bin/mdls -name kMDItemPageWidth " & quoted form of (POSIX path of this_item as string)
set pageWidth to my str_replace("kMDItemPageWidth = ", "", pageWidth)

if (pageHeight as number) is greater than (pageWidth as number) then
set pdf_resolution to round (1000 / (pageHeight as number) * 72) rounding up
else
set pdf_resolution to round (1000 / (pageWidth as number) * 72) rounding up
end if

open this_item as PDF with options {class:PDF open options, resolution:pdf_resolution, mode:RGB, use antialias:true, suppress warnings:false, use page number:true, page:1, crop page:media box}

I used "rounding up" to ensure that the result is equal to or slightly over my target resolution. It's only ballpark accurate, but it's better than what I started with.

Answer 3

Thanks zanseattle I was having the same problem!

@ Philip Regan: lol for completely missing the point, especially ending your misdirected discussion of zanseattle's great solution with "sorry" haha.