"PDF Open Options" in 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

Thanks for that!
(If those parameters are deprecated since CS2, it's probably bad form for Adobe to use them in their documentation for CS3. Just sayin'!)
Anyway, it looks like the shell script you quoted gives the page height in points with an assumed resolution of 72 DPI. I can use that with my target dimension to calculate what to set the resolution to.
In case it helps anyone else, here's the working code I came up with:
-- ("str_replace" is a custom function to find and replace text in a string, it's not built-in to Applescript)
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
try
with timeout of 5 seconds
open alias ("WABEL0457937:Users:Charles:Desktop:Test:image_prep:" & image_id & ".pdf") 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}
end timeout
on error
-- I have some sections here that check for and handle progress windows, password prompts, and such
-- so the script can either continue or fail gracefully
end try
All of the images coming out of this script are just over 1000 pixels at their widest dimension. Since it's not critical that they be exactly 1000 (just very close), I was able to completely eliminate the resizing portion of the script to save even more processing time.
Thanks for the pointers, everyone!