I have a need to make a bunch of PDF's into high-quality PNG files. I have done 14 so far, and for some reason there is a variance in a couple instances that is driving me nuts.

I open each PDF in Photoshop CS6 64-bit and save it for the web as a PNG. Every time I use the exact same settings. This is an example of most of the files outputting correctly:

On the Left is the PNG, on the right is the original PDF  Note the dark lines and weight of the lines

Incidentally, the blue tinged background is because they are transparent and the system image previewer in windows has this bluish background.

Here is an example of one of the few that does not output correctly.

On the Left is the PNG, on the right is the original PDF. Note how the lines are very light in the PNG as compared to the PDF

I have looked at everything I can think of to try to account for some difference, but I cannot figure it out. Any help in pointing me in the right direction would be appreciated. Much thanks in advance!

  • Are you referring tot he very faint, fine paths in sample 2?? For the untrained eye, can you explain what's different? My guess would be those thin lines are smaller than 1pt or 1pixel so they are being anti-aliased. – Scott Mar 3 '15 at 2:04
  • Yes the faint lines in the sample 2 PNG. Both PDF's are using the same line weight and so in theory I would expect the sample 2 PNG's lines to look dark like my sample 1. Nonetheless, your thought bares checking, so I will take a look and make sure the lines are the same weight. Thanks! – BitBug Mar 3 '15 at 2:51
  • for converting a file from pdf to PNG use pdf2png.com – Mohammad Kermani Mar 3 '15 at 5:07
  • How are the results when you export to PNG using Acrobat? – Max Wyss Mar 3 '15 at 11:11
  • It is left unsaid, but they look OK in Photoshop before export? Have you tried, for the sake of testing, placing a solid white layer below the line drawing and flattening before export? Is there color information that is getting flattened on export (i.e. 256 grey levels flattened to 8 etc) – Yorik Mar 3 '15 at 16:38

PDF is a vector kind of file and it's better handled in a Illustrator.
If you open it in illustrator you can break down the items (release clipping mask and break compound path) and then you should check:
-Line width
-Line Opacity
-Line Color
Once you have checked everything you can export the entire thing with: File>export>PNG, then choose "use artboards" and if you need to change the background transparency to white.

| improve this answer | |

@Scott gets credit for making me think about anti-alias being the culprit which led me to a solution.

When you open a PDF in Photoshop CS6 it starts with an Import PDF dialog box. In the section Page Options is a check box for Anit-aliased. That box was checked by default. Unchecking this box solved the issue and my PNG came out great!

enter image description here

Thank you to all for your help!

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.