How to increase the contrast for a PDF file in a batch method

[朱裕85022250]

I have a pdf file to processing here.

I note I can import the pdf file as a image for every page content. like this

I can auto-adjust the contrast by Alt+Shitf+Ctrl+L for every page. Then I will get a very good page like this

I have to say I get a larger improvement for this page, but if my pdf have 200+ pages, I don't know how to adjust and export it in batch method. Can anybody help me out?

[c.pfaffenbichler · Accepted solution]

That seems to be a fairly suboptimal pdf to begin with … the type appears to be pixels.

I am afraid the task exceeds Photoshop’s default functionality, but Scripting would provide a work-around:

Photoshop Scripting

But mind you: The pages apparently already being images you should open the images, not the pages, to avoid resampling and the ensuing image degradation.

[c.pfaffenbichler]

When you post over n the Scripting Forum please also explain what exact output you want to get: file format, individual images, a re-assembled pdf, …

[c.pfaffenbichler]

But maybe I am misunderstanding your intention and Image Processor would suffice.

[c.pfaffenbichler]

Have you made any headway on this issue yet?

[朱裕85022250]

Thanks very much. I have make it by c++ and OpenCV afterwards.. Sorry for later response, I have to say I get none notification about your answer totally..

[richdesign00]

This seems like it should be a fairly obvious feature for Acrobat to have - but then Acrobat is a weird product.

The best I have found is to export the pages as images, batch process each image in Photoshop as required and then use the Photoshop PDF Presentation feature (File/ Automate/ PDF Presentation) to recombine the images back into a PDF with control over the compression (Acrobat seems to compress images if imported directly using Combine files).

[c.pfaffenbichler]

The best I have found is to export the pages as images

Which would be a bad idea if the text was type or the pdf contained vector components, which in this case does not seem to be the case, though.

[richdesign00]

I was assuming scanned text, therefore a raster format.