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adwul62
Inspiring
February 20, 2022
Answered

Why are my scanned documents so blurry?

  • February 20, 2022
  • 2 replies
  • 19649 views

I vainly spent a lot of time on trying to get text of scanned documents look crispy.

For one reason or the other they look blurry.

Attached 3 examples.

It is screenshot of text from Word, saved as a PNG file

1. Left is the screenshot opened by a viewer
2. In the middle is that screenshot converted to PDF - r-click convert to PDF - no, or no significant, loss
3. I printed the PNG file, printout looked fine, and then scanned it - result on the right.
View is 100%, scan is 300dpi, document size A4 (210x297mm) scanner Epson 5620

 

FWIW I have put some screenshots here.

 

Hope someone has a clue...

Thanks in advance.

 

    This topic has been closed for replies.
    Correct answer adwul62

    @gary_sc 
    For your info, the settings I am scanning with are in the 4th attachment. 300dpi. At that point there is 'Exact Search'

     

     

     

     

     

    However, I just found out: I should disable optimize... resulting in a fine scan. 

    have added them as an attachment as I believe they don't come thru when pasting in this thread.
    Pls do check out the attachments.

     

     

     

     

    2 replies

    gary_sc
    Community Expert
    gary_scCommunity Expert
    Community Expert
    February 21, 2022

    Hi Adwul62,

     

    Quick question for you. First, thanks for showing us your application settings, that helps. However, there was one I did not see. If you go to the Settings in OCR, you can get there one way here (there are several ways to this setting)

    After opening that up, there are three ways to process the content, see below:

    Which of the three ways is your system set to? Whatever it is set to, please try one of the others.

     

    Also, I noticed that in your 3nd screenshot, you show using PNG format. Please try selecting TIF.

     

    Lastly, In the last screenshot, there is an option to use the Scanner's software ("Show Scanner's User Interface.") Can you show what the default settings are when that box is checked?

     

    Thank you,

     

     

     

    A
    adwul62AuthorCorrect answer
    Inspiring
    February 22, 2022

    @gary_sc 
    For your info, the settings I am scanning with are in the 4th attachment. 300dpi. At that point there is 'Exact Search'

     

     

     

     

     

    However, I just found out: I should disable optimize... resulting in a fine scan. 

    have added them as an attachment as I believe they don't come thru when pasting in this thread.
    Pls do check out the attachments.

     

     

     

     

    gary_sc
    Community Expert
    gary_scCommunity Expert
    Community Expert
    February 24, 2022

    Hello again, 

    Thank you very much for your elaborate reply. Truly appreciated.

    Usually, when scanning documents, the ADF of my printer is  used (i.e. the Automatic Document Feeder).
    Frankly, not being an expert at all, Acrobat is mostly set to use its default settings.
    For example: vainly searched but did not find any settings relating to scanning, specifically how to disable 'Optimize Image' by default. It is something one tends to forget when starting the next scan, so the result may be blurry again, hence the scan should be performed again...
    Any suggestions?


    Another example: all these years, after scanning, or whatever, Acrobat showed the page in a different size (not 100%).
    It could be 108%, or 112%, so I changed it to 100% in the dropdown.
    Didn't know what and how to set this in the Preferences > Page Display. I know, it is just a minor thing, but still...
    Just now, whilst writing here and going thru the settings again, I think... I have found it. 

     

    Peferences > Accessibility:

    Override Page Display
    v Always use Page Layout Style: Single Page
    v Always use Zoom Setting: 100%    < instead of 'Fit Page'.

     

    As for the PDF size, to be honest, I do not care too much. Diskspace is cheap, some of my PDF files are 500-600 and one even 750MB.

    As for PNG converting I have set this as below. I believe this is correct for the best possible results?
    I know about TIFF being the best possible format (huge format), however, in my case, considering that usually any image that may require converting, are screenshots only.

    Below are the settings.

     

     

    Again thanks for your help!


    Hi Adwul62,

     

    OK, lots of stuff to cover here, let's see what I can do. First off, let me point out that I'm on a Mac, and my scanner is a flatbed photograph scanner (Epson V800), so my options are different from yours. As such, I cannot know for sure. So, I have no real knowledge of what to suggest so that you do not have to always reset the "Optimize Image." Please remember that Acrobat cannot scan and everything that you see is Acrobat dealing with your scanner's software. 

     

    The 100% issue, congrats, that's what you needed. 

     

    Disk space issues: Yes, you are correct about how cheap disk space is. However, there are other considerations to be aware of. The larger the document size, the more computer resources may be needed to process and work with that document. Add to the challenges that one has to electronically send that document to someone else (and the imposition to send a very large document to someone who may not have as much RAM or disk storage as you). I might be comparing apples to avocados here but my camera can take a 20 MB image. That's 5472 p x 3648 p. If I converted that image to the TIF (no compression) format, it's about 57 MB storage size. If I bring that down to 1500 pixels wide (the size one should bring it to for email purposes, as a TIF image it's now down to 4.3 MB. If I save that as a JPG, it's 480 kb. Now, I have lots of storage space but that does not justify sending you that image that's 57 MB. [Note: if you double the size of an image, the storage size quadruples.]

     

    PNG format: be aware that there are two kinds of PNG: 8-bit and 24-bit. The former can contain up to 256 different shades and colors. The 24-bit can contain up to 12 million shades and colors. But if you have a document that is a text document saved in 24-bit, it will be significantly larger than the 8-bit. Unfortunately, Adobe does not specify which one they are using (and I do not know).

     

    Here's another piece of trivia. when I scan a full page of text as a TIF document, it's about 8 MB. When I convert that into a PDF, it's about 80-150 kb. Same document. [Caveat to that: if I have lots of background imagery, that gets PDFed as well and the document can easily be 2-4 MB.

     

    What all this is to say is that you need to experiment and see what works and what's best for you. Also, be considerate: what's best for you may not be the same as to whom you send a document. It's the "and then what" syndrome. If you send a 750 MB document to someone, then what do they do with it? How will/can you send it?

     

    Hey, if it was all easy, how much fun would that be??

     

     

    Amal.
    Community Manager
    Amal.Community Manager
    Community Manager
    February 21, 2022

    Hi there

     

    Hope you are doing well and sorry to hear that.

     

    Would you mind sharing the version of the Acrobat DC you are using? To check the version go to Help > About Acrobat and make sure you have the recent version 21.11.20039. Go to Help > Check for updates and reboot the computer once.

     

    Also try to create the PDF from the scanner as described here https://helpx.adobe.com/acrobat/using/scan-documents-pdf.html and see if that works for you.

     

    Also check for any missing/pending updates for scanner driver and firmware and try updating it and check.

     

    Regards

    Amal

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