Signature image appears blurry and discolored

[axel_7277]

Hello Adobe Community,

I’ve encountered a rendering issue in the latest release of Adobe Acrobat Reader DC (64-bit, Windows 11, 25.001.20630).

When using qualified electronic signatures (QES) created with Digiseal desktop software, the signature image inside the signed PDF looks blurry, slightly grayish, and less color-accurate in the latest Acrobat Reader DC.

However:

• In older Acrobat Reader DC  of this year versions (e.g. 25.001.20577,), the same signed PDF displays the signature image perfectly — sharp and color-accurate.

• In other PDF viewers (Edge, Foxit, Sumatra, etc.), the PDFs also display perfectly.

If i print the file the ourcome is terrible.

I tried a lot with Digiseal to use different images and formats, field sizes, image sizes. Sometimes it gets a little better but nothing works like it did before.

As this is a big deal for me i would welcome any help or insights that could help me out!

Thanks a lot!

[Amal.]

Hi there,

Hope you are doing well and thanks for reaching out and for providing such detailed information about the issue.

From what you describe, the problem seems specific to the latest release of Acrobat Reader DC (25.001.20630) and how it renders the signature appearance from Digiseal QES. Since the same PDF displays correctly in earlier Acrobat versions and in other PDF viewers, this points to a rendering change or regression introduced in the new build.

A few things you can try:

1. Check other digital signatures: Please try to use a different digital signature (other than Digiseal QES) and check if the issue exists. Try to create a new digital signature as described here: https://adobe.ly/4oNbvKH 

2. Check your rendering preferences: Go Preferences (Ctrl,Cmd+K) > Page Display and select Smooth Images or change the Rendering settings to see if this improves clarity.

3. Test with “Enable Enhanced Security” disabled: Sometimes, security restrictions can affect how signature appearances load. Go to Preferences (Ctrl,Cmd+K) > Enhanced Security > Turn Off the Protected mode at start up and Uncheck , enhanced Security > Click OK and reboot the application and see if that helps.
Note: Please turn on the security after testing to avoid any security risk.

Let us know how it goes. 

~Amal

[axel_7277]

Hi, thanks for your suggestions. I tested the proposed steps, but unfortunately the issue persists:

1. Testing with a different digital signature
   I created different signatures that did not work out. The issue still occurs. 

2. Disabling Enhanced Security & Protected Mode
   I turned off both “Enable Protected Mode at startup” and “Enable Enhanced Security” in Preferences and restarted Acrobat.
   → No improvement, the problem remains.

3. Checking rendering preferences
   I have tested changing the the settings, but the problem also exists across different signature images and formats, and it only affects the latest Acrobat Reader DC builds.
   Since the same PDFs display perfectly in older Acrobat Reader DC versions and in other PDF viewers, this strongly suggests a regression in the current rendering engine rather than a configuration problem on my end (?)

4. Could you please escalate this issue to the engineering team? It seems specific to how Acrobat now renders signature appearance streams in the newest release.

[MikelKlink]

Can you share an example PDF illustrating the issue for analysis?

Could you please escalate this issue to the engineering team? It seems specific to how Acrobat now renders signature appearance streams in the newest release.

Please be aware that the issue might not be an error of the newest Acrobat but actually a fix in it; the way the software in question creates the appearance might be wrong and only an error in earlier Acrobat versions might have allowed it to render as intended; other PDF viewers might have followed Acrobat in that error. 

(I don't say that necessarily is the case, but it just might be.)

[axel_7277]

Hi again (and thank you for every support!),

i tried a lot of different ways and sigantures that i use and worked with chat gpt to maybe find a solution for myself. after a lot of reseach i still cant help myself, but i have a signature that works "fine" and one that does not...

If i compare the two PDFs (unfortunately i cant share them because of the sensitive images of my signature and seal) i have a PDF with a signature image that renders perfectly and another one where the signature image looks blurry and slightly grayish in the latest Acrobat Reader DC.

Here some conect chat gpt gabe to me:

Important findings from the technical comparison:

• Both PDFs are created using the same software (Digiseal Desktop) and the same image format (24-bit PNG).

• In older Acrobat Reader DC versions both PDFs render perfectly.

• In all other PDF viewers (Edge, Foxit, Sumatra etc.), both PDFs render perfectly.

• The only technical difference inside the PDFs is:

  • Good PDF → /FlateDecode + /DeviceRGB

  • Bad PDF → /DCTDecode + /CalRGB

This strongly suggests that recent Acrobat versions handle /CalRGB images embedded via /DCTDecode differently, which leads to blurry and grayish rendering — even though the PDFs themselves are perfectly valid and QES-compliant.

The attached PDF contains a signature "test" that looks terrible in the latest adobe version and "good" in the older ones. Maybe you might have a look if this might be an error or a fix...

[Amal.]

Hi there 

Thanks for sharing the details, Please give us some time to get it checked with the development team, we will share the update as soon as we get any information.

Thank you for your understanding.

~Amal

[Amal.]

Hi there, our engineering team is unable to reproduce the issue in house and need more information.

Could you share a screenshot of the 'About Acrobat' box. Click on the hamburger menu at the top left of the application > Help > About Adobe Acrobat.  

~Amal

[Damian_K_6128]

I have joined this forum specifically to back up Axel's findings.

I represent a major healthcare company in my country that monitors the health and well-being of all children born in this country under the age of 5.

As part of our services, we generate growth charts over time for each of the children in our care.

these growth charts are provided to the parents of said children, so this issue not only affects our staff, but also members of the public provided said growth charts for their children.

we use a custom tool to generate these growth chart graphs as image elements which are then embeded into a PDF file.

While investigating the issue detailed by Axel above, we identified that these graph image elements are using a CalRGB colour profile, while our organisation logo does not.

the organisation logo displays perfectly (DeviceRGB) while the graph images (CalRGB) are distorted in exactly the same way that axel describes.

We have implemented a work-around were all future growth charts will be generated using DeviceRGB colour profile and the new charts look fine, but we have thousands of PDF files out there with families that still contain the offending CalRGB profile.

As Axel has stated, only the latest version of the Acrobat Reader desktop application are affected.  all other PDF viewers (including the Adobe Chrome Extension) display correctly.

We look forward to you resolving this issue in a future patch.
(I can't supply you any examples as the growth charts include private medical data of the children)

[Amal.]

Hi there 

Hope you are doing well and sorry for the trouble. 

Could you share the screenshot of the 'About Acrobat' box as requested earlier, so that our engineering team may  further look into it.

~Amal

[axel_7277]

I’ve attached a screenshot showing the versions I’m using.

Additionally, I’ve conducted several tests that may have brought me closer to understanding the issue — at least partially:

• When running Adobe Acrobat Reader DC inside a Hyper-V virtual machine (tested on both Windows 10 and Windows 11) over RDP, the described rendering problem with the signature image always occurs.

• However, when I tested the same PDFs on a physical desktop PC using the latest Acrobat Reader version, the issue does NOT occur — everything looks sharp and color-accurate.

• This suggests that the problem might be related to rendering or GPU handling in a virtualized environment.

I have already tried several approaches, including:

• Setting bEnableHardwareAcceleration=0 in the registry

• Launching Acrobat with the /disableDirectX start parameter

• Changing the Windows graphics settings to force Acrobat into power-saving mode

Unfortunately, none of these workarounds improved the situation.

[Amal.]

Hi there 

Thanks for sharing the details. 

Please give us some time to get this checked by our development team. We will share the update soon.

~Amal

[Amal. · Accepted solution]

Hi there, 

Our team has checked the details you shared and found that you are using the 32-bit version of the Acrobat Reader application. They are working on a fix for this issue. We will share the update as soon as we get more information. 

As a workaround, you can try using the 64-bit version of the Acrobat Reader application here: https://get.adobe.com/reader/enterprise/  and see if that works for you. 

~Amal

[axel_7277]

After switching to the 64-bit version of Adobe Acrobat Reader DC, the issue with the blurry and grayish signature images is resolved. I really appreciate the help!

However, I would like to ask whether there are any plans to fix this problem in the 32-bit version as well.
My signed documents are frequently used by customers, authorities and external partners, and i am sure many of them are still using the 32-bit version of Acrobat Reader.
I would like to avoid situations where my signature appearance looks incorrect or unprofessional on their systems....

[PravalJain]

Apologies for the inconvience. This issue is fixed in the latest update. Release notes - https://www.adobe.com/devnet-docs/acrobatetk/tools/ReleaseNotesDC/continuous/dccontinuoussep2025sec.....

Please do a "Help -> Check for updates" to update to the latest version and let us know if you still see issues.