Adjust Contrast/Brightness in Multi-Page PDFs?

[tallis]

Hey there. Are there any programs that easily allow one to adjust the brightness and contrast in multi-page pdf files? I know I do it one page at a time in Photoshop, but with a book-length scan, this is not a practical option. Thanks in advance for your help.

[Natobasso]

Yes! You can perform "Batch" functions by selecting all pages in a doc opened in preview and any action you choose gets applied to all pages. More here (scroll down to #5):
http://www.usingmac.com/2008/8/5/10-...ication-tricks

[tallis]

Strangely, when working with a b/w .pdf, the "Adjust Color" option is greyed out in the Preview menu. Very frustrating.

[Natobasso]

Um, it's because there's no color in black and white pdfs. You have to adjust contrast or brightness only with b/w pdfs.

[tallis]

Well, yes, I realize there's no color. The problem is that the brightness/contrast adjustment in Preview as described by the link you posted is hidden in the "Adjust Color" option. If you can successfully adjust the contrast or brightness on a multi page BW pdf and explain how you did it without separating the pages, I'd be really grateful.

Thanks!

[tallis]

Bump? Still haven't figured this one out.

[Natobasso]

1. Open the pdf in Preview.
2. Make sure the preview pages are showing
3. Click page one
4. "Select All" (or Command + A), All pages are selected
5. Run any Preview tool/filter and all pages will be affected simultaneously

If your pdf is locked, you will not be able to perform this operation.

[tallis]

Again, "adjust color" is still greyed out on all pdf files for me, including the unlocked ones. It works fine on jpegs. Is there some tool or filter set that I'm somehow missing that is controllable from elsewhere than the "adjust color" option?